Coffee and tea consumption, patient-reported, and clinical outcomes in a longitudinal study of patients with breast cancer

Background

Higher consumption of coffee and tea has been associated with improved health outcomes in the general population and improved breast cancer (BC) prognosis. This study investigated patterns of coffee and tea consumption and association with patient‐reported outcomes (PROs) and clinical outcomes among survivors of BC.

Methods

The authors included survivors of stage I–III BC enrolled in the CANTO cohort (NCT01993498) that provided post‐treatment assessment of coffee and tea consumption from years 1 to 4 after diagnosis. Group‐based trajectory modeling clustered patients according to daily consumption of coffee and tea. Multivariable mixed models and Cox models examined associations between consumption, PROs and clinical outcomes.

Results

Among 3788 patients, the authors identified four stable patterns of consumption: “Low” (25.8%), “Moderate” (37.6%), “High” (25.3%), and “Very high” (11.3%), corresponding to <1, 2, 3, and ≥ 4 cups of coffee and/or tea per day. Patients in the “Very high” group (vs. “Low”), were more likely to be younger, smokers, with higher monthly income and education. PROs and survival outcomes were similar across the four groups.

Conclusions

Over one in three survivors of BC reported high or very high consumption of coffee and/or tea. The authors found no association between higher consumption of coffee and/or tea, worse PROs and clinical outcomes.

More than 30% of survivors of breast cancer report high post‐diagnostic consumption of coffee and tea. In this study, the authors did not find any detrimental association between higher consumption of coffee and tea and patient‐reported or clinical outcomes.

Low level of Fibrillarin, a ribosome biogenesis factor, is a new independent marker of poor outcome in breast cancer

Background

A current critical need remains in the identification of prognostic and predictive markers in early breast cancer. It appears that a distinctive trait of cancer cells is their addiction to hyperactivation of ribosome biogenesis. Thus, ribosome biogenesis might be an innovative source of biomarkers that remains to be evaluated.

Methods

Here, fibrillarin (FBL) was used as a surrogate marker of ribosome biogenesis due to its essential role in the early steps of ribosome biogenesis and its association with poor prognosis in breast cancer when overexpressed. Using 3,275 non-metastatic primary breast tumors, we analysed FBL mRNA expression levels and protein nucleolar organisation. Usage of TCGA dataset allowed transcriptomic comparison between the different FBL expression levels-related breast tumours.

Results

We unexpectedly discovered that in addition to breast tumours expressing high level of FBL, about 10% of the breast tumors express low level of FBL. A correlation between low FBL mRNA level and lack of FBL detection at protein level using immunohistochemistry was observed. Interestingly, multivariate analyses revealed that these low FBL tumors displayed poor outcome compared to current clinical gold standards. Transcriptomic data revealed that FBL expression is proportionally associated with distinct amount of ribosomes, low FBL level being associated with low amount of ribosomes. Moreover, the molecular programs supported by low and high FBL expressing tumors were distinct.

Conclusion

Altogether, we identified FBL as a powerful ribosome biogenesis-related independent marker of breast cancer outcome. Surprisingly we unveil a dual association of the ribosome biogenesis FBL factor with prognosis. These data suggest that hyper- but also hypo-activation of ribosome biogenesis are molecular traits of distinct tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09552-x.

CANTO-RT: Skin toxicities evaluation of a multicenter large prospective cohort of irradiated patients for early-stage breast cancer

Skin damage is the most common and most important toxicity during and after radiotherapy. Its assessment and understanding of the factors influencing its occurrence, is a major issue in the management of patients irradiated for an early breast cancer CANTO is a prospective clinical cohort study of 10 150 patients with stage I-III BC treated from 2012-2017 in 26 cancer centers. In this study, we used CANTO-RT, a sub-cohort of CANTO, including 3480 patients who received RT. We are focus on specifical skin toxicities: Erythema, fibrosis, telangiectasia, and cutaneous pigmentation The prevalence of toxicities of interest varied over time, so at M3-6, 41.1% of patients had erythema while 24.8% of patients had fibrosis. At M12 and M36, the prevalence of erythema decreased respectively while fibrosis remains stable. The prevalence of telangiectasia increases from 1% to 7.1% from M3-6 to M36. After adjustments, we showed an association between the occurrence of skin erythema and obesity; the type of surgery; the presence of axillary dissection; the use of taxane-based CT and the 3DvsIMRT irradiation technique. Regarding fibrosis, an association is found, at M3-6, with age at diagnosis, obesity, tobacco, and the use of boost. Only obesity and the type of surgery received by the patient remained statistically significant at M12 and M36. In this study we identified several risk factors for acute and late skin. The use of a boost was mainly related to the occurrence of fibrosis while the use of IMRT-type technique decreased the occurrence of skin erythema.

Dynamics of Long-Term Patient-Reported Quality of Life and Health Behaviors After Adjuvant Breast Cancer Chemotherapy

We aimed to characterize long-term quality of life (QOL) trajectories among patients with breast cancer treated with adjuvant chemotherapy and to identify related patterns of health behaviors.

Somatic Genomic Testing in Patients With Metastatic or Advanced Cancer: ASCO Provisional Clinical Opinion

PURPOSE

An ASCO provisional clinical opinion offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This provisional clinical opinion addresses the appropriate use of tumor genomic testing in patients with metastatic or advanced solid tumors.

CLINICAL CONTEXT

An increasing number of therapies are approved to treat cancers harboring specific genomic biomarkers. However, there is a lack of clarity as to when tumor genomic sequencing should be ordered, what type of assays should be performed, and how to interpret the results for treatment selection.

PROVISIONAL CLINICAL OPINION

Patients with metastatic or advanced cancer should undergo genomic sequencing in a certified laboratory if the presence of one or more specific genomic alterations has regulatory approval as biomarkers to guide the use of or exclusion from certain treatments for their disease. Multigene panel-based assays should be used if more than one biomarker-linked therapy is approved for the patient's disease. Site-agnostic approvals for any cancer with a high tumor mutation burden, mismatch repair deficiency, or neurotrophic tyrosine receptor kinase (NTRK) fusions provide a rationale for genomic testing for all solid tumors. Multigene testing may also assist in treatment selection by identifying additional targets when there are few or no genotype-based therapy approvals for the patient's disease. For treatment planning, the clinician should consider the functional impact of the targeted alteration and expected efficacy of genomic biomarker-linked options relative to other approved or investigational treatments.Additional information is available at www.asco.org/assays-and-predictive-markers-guidelines.

The Polarity and Specificity of Antiviral T Lymphocyte Responses Determine Susceptibility to SARS-CoV-2 Infection in Patients with Cancer and Healthy Individuals

Vaccination against coronavirus disease 2019 (COVID-19) relies on the in-depth understanding of protective immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We characterized the polarity and specificity of memory T cells directed against SARS-CoV-2 viral lysates and peptides to determine correlates with spontaneous, virus-elicited, or vaccine-induced protection against COVID-19 in disease-free and cancer-bearing individuals. A disbalance between type 1 and 2 cytokine release was associated with high susceptibility to COVID-19. Individuals susceptible to infection exhibited a specific deficit in the T helper 1/T cytotoxic 1 (Th1/Tc1) peptide repertoire affecting the receptor binding domain of the spike protein (S1-RBD), a hotspot of viral mutations. Current vaccines triggered Th1/Tc1 responses in only a fraction of all subject categories, more effectively against the original sequence of S1-RBD than that from viral variants. We speculate that the next generation of vaccines should elicit Th1/Tc1 T-cell responses against the S1-RBD domain of emerging viral variants.

SIGNIFICANCE

This study prospectively analyzed virus-specific T-cell correlates of protection against COVID-19 in healthy and cancer-bearing individuals. A disbalance between Th1/Th2 recall responses conferred susceptibility to COVID-19 in both populations, coinciding with selective defects in Th1 recognition of the receptor binding domain of spike. See related commentary by McGary and Vardhana, p. 892. This article is highlighted in the In This Issue feature, p. 873.

Characterization of Depressive Symptoms Trajectories After Breast Cancer Diagnosis in Women in France

IMPORTANCE

Breast cancer (BC) diagnosis and treatment expose patients to a 5-fold higher risk of depression compared with the general population, with an estimated prevalence of 10% to 25%. A depressive episode in patients with BC has implications for the tolerance of and adherence to treatment, impairing quality of life and reducing life expectancy.

OBJECTIVE

To identify and characterize distinct longitudinal patterns of depressive symptoms in patients with BC from diagnosis to 3 years after treatment.

DESIGN, SETTINGS, AND PARTICIPANTS

The CANTO-DEePRESS (Deeper in the Understanding and Prevention of Depression in Breast Cancer Patients) cohort study included women in the French multicenter CANTO (CANcer TOxicities) cohort study (conducted between March 20, 2012 and December 11, 2018), who were 18 years or older with invasive stage I to III BC and no previous BC treatment. The study aimed to characterize toxicities over a 5-year period following stage I to III primary BC treatment. Assessments of depressive symptoms were performed on a subset of patients with available data at diagnosis and at least 2 other time points. All data were extracted from the CANTO database on October 1, 2020.

MAIN OUTCOMES AND MEASURES

The primary outcome was the level of depressive symptoms at each assessment time point measured with the Hospital Anxiety and Depression Scale and depression subscale at BC diagnosis and at 3 to 6, 12, and 36 months after the end of treatment. The group-based trajectory modeling was used to identify trajectory groups, and multinomial logistic regression models were used to characterize the following factors associated with trajectory group affiliation: demographic, socioeconomic, clinical, lifestyle, and quality-of-life data.

RESULTS

A total of 4803 women (mean [SD] age, 56.2 [11.2] years; 2441 patients [50.8%] with stage I BC) were included in the study. Six trajectory groups that described the heterogeneity in the expression of depressive symptoms were identified: noncases with no expression of symptoms (n = 2634 [54.8%]), intermediate worsening (1076 [22.4%]), intermediate improvement (480 [10.0%]), remission (261 [5.4%]), delayed occurrence (200 [4.2%]), and stable depression (152 [3.2%]). HADS-D scores at diagnosis were consistently associated with the 5 depressive trajectory group affiliations, with an estimated higher probability per point increase of experiencing subthreshold or clinically significant depressive symptoms between diagnosis and the 3 years after the end of BC treatment. The higher probabilities ranged from 1.49 (95% CI, 1.43-1.54) for the intermediate worsening group to 10.53 (95% CI, 8.84-12.55) for the stable depression group. Trajectory groups with depressive symptoms differed from the noncases group without symptoms by demographic and clinical factors, such as having dependent children, lower household income, cancer stage, family history of BC, previous psychiatric hospitalizations, obesity, smoking status, higher levels of fatigue, and depression at diagnosis.

CONCLUSIONS AND RELEVANCE

In this cohort study, nearly a third of patients with BC experienced temporary or lasting significant depressive symptoms during and after treatment. Improving early identification of women at risk of developing long-term or delayed depression is therefore critical to increase quality of life and overall survival. Subjected to validation, this study is an important first step toward personalized care of patients with BC at risk of depression.

Pan-cancer Analysis of Homologous Recombination Repair-associated Gene Alterations and Genome-wide Loss-of-Heterozygosity Score

PURPOSE

To study associations across tumor types between genome-wide loss of heterozygosity (gLOH) and alterations in homologous recombination repair (HRR)-associated genes beyond BRCA1 and BRCA2.

EXPERIMENTAL DESIGN

Genomic profiling using a targeted next-generation sequencing assay examining 324-465 genes (FoundationOne, FoundationOne Heme, and FoundationOne CDx; Foundation Medicine, Inc.) was performed in a cohort of 160,790 samples across different tumor types. Zygosity predictions and gLOH status were calculated and linked with alterations in 18 HRR-associated genes (BRCA1, BRCA2, PALB2, BARD1, ATR, ATRX, ATM, BAP1, RAD51B, RAD51C, RAD51D, BRIP1, NBN, CHEK1, CHEK2, FANCA, FANCC, MRE11) and other genomic features, using Fisher's exact test and Mann-Whitney U tests.

RESULTS

We identified a strong correlation between elevated gLOH and biallelic alterations in a core set of HRR-associated genes beyond BRCA1 and BRCA2, such as BARD1, PALB2, FANCC, RAD51C, and RAD51D (particularly in breast, ovarian, pancreatic, and prostate cancer). Monoallelic/heterozygous alterations in HRR-associated genes were not associated with elevated gLOH. gLOH was also independently associated with TP53 loss. Co-occurrence of TP53 loss and alterations in HRR-associated genes, and combined loss of TP53-PTEN or TP53-RB1, was associated with a higher gLOH than each of the events separately.

CONCLUSIONS

Biallelic alterations in core HRR-associated genes are frequent, strongly associated with elevated gLOH, and enriched in breast, ovarian, pancreatic, and prostate cancer. This analysis could inform the design of the next generation of clinical trials examining DNA repair-targeting agents, including PARP inhibitors.

Long-Term Longitudinal Patterns of Patient-Reported Fatigue After Breast Cancer: A Group-Based Trajectory Analysis

PURPOSE

Fatigue is recognized as one of the most burdensome and long-lasting adverse effects of cancer and cancer treatment. We aimed to characterize long-term fatigue trajectories among breast cancer survivors.

METHODS

We performed a detailed longitudinal analysis of fatigue using a large ongoing national prospective clinical study (CANcer TOxicity, ClinicalTrials.gov identifier: NCT01993498) of patients with stage I-III breast cancer treated from 2012 to 2015. Fatigue was assessed at diagnosis and year 1, 2, and 4 postdiagnosis. Baseline clinical, sociodemographic, behavioral, tumor-related, and treatment-related characteristics were available. Trajectories of fatigue and risk factors of trajectory-group membership were identified by iterative estimates of group-based trajectory models.

RESULTS

Three trajectory groups were identified for severe global fatigue (n = 4,173). Twenty-one percent of patients were in the high-risk group, having risk estimates of severe global fatigue of 94.8% (95% CI, 86.6 to 100.0) at diagnosis and 64.6% (95% CI, 59.2 to 70.1) at year 4; 19% of patients clustered in the deteriorating group with risk estimates of severe global fatigue of 13.8% (95% CI, 6.7 to 20.9) at diagnosis and 64.5% (95% CI, 57.3 to 71.8) at year 4; 60% were in the low-risk group with risk estimates of 3.6% (95% CI, 2.5 to 4.7) at diagnosis and 9.6% (95% CI, 7.5 to 11.7) at year 4. The distinct dimensions of fatigue clustered in different trajectory groups than those identified by severe global fatigue, being differentially affected by sociodemographic, clinical, and treatment-related factors.

CONCLUSION

Our findings highlight the multidimensional nature of cancer-related fatigue and the complexity of its risk factors. This study helps to identify patients with increased risk of severe fatigue and to inform personalized interventions to ameliorate this problem.

Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer

BACKGROUND

In a previous analysis of this phase 3 trial, first-line ribociclib plus letrozole resulted in significantly longer progression-free survival than letrozole alone among postmenopausal patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether overall survival would also be longer with ribociclib was not known.

METHODS

Here we report the results of the protocol-specified final analysis of overall survival, a key secondary end point. Patients were randomly assigned in a 1:1 ratio to receive either ribociclib or placebo in combination with letrozole. Overall survival was assessed with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods after 400 deaths had occurred. A hierarchical testing strategy was used for the analysis of progression-free survival and overall survival to ensure the validity of the findings.

RESULTS

After a median follow-up of 6.6 years, 181 deaths had occurred among 334 patients (54.2%) in the ribociclib group and 219 among 334 (65.6%) in the placebo group. Ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole. Median overall survival was 63.9 months (95% confidence interval [CI], 52.4 to 71.0) with ribociclib plus letrozole and 51.4 months (95% CI, 47.2 to 59.7) with placebo plus letrozole (hazard ratio for death, 0.76; 95% CI, 0.63 to 0.93; two-sided P = 0.008). No new safety signals were observed.

CONCLUSIONS

First-line therapy with ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole in patients with HR-positive, HER2-negative advanced breast cancer. Median overall survival was more than 12 months longer with ribociclib than with placebo. (Funded by Novartis; MONALEESA-2 ClinicalTrials.gov number, NCT01958021.).

Randomised, open-label, multicentric phase III trial to evaluate the safety and efficacy of palbociclib in combination with endocrine therapy, guided by ESR1 mutation monitoring in oestrogen receptor-positive, HER2-negative metastatic breast cancer patients: study design of PADA-1

INTRODUCTION

The combination of a CDK4/6 inhibitor with an aromatase inhibitor (AI) has recently become the gold standard for AI-sensitive first line treatment of oestrogen receptor-positive (ER+) HER2-negative (HER2-) advanced breast cancer. However, most patients receiving this combination will ultimately progress and require further therapies.Several studies have demonstrated that the onset of a ESR1 gene mutation lead to AIs resistance in the advanced setting. ESR1 mutations can be detected in circulating tumour DNA (ctDNA) using a digital PCR assay. Our study aims to prove the clinical efficacy of periodic monitoring for emerging or rise of ESR1 mutations in ctDNA to trigger an early change from AI plus palbociclib to fulvestrant plus palbociclib treatment while assessing global safety.

METHODS

PADA-1 is a randomised, open-label, multicentric, phase III trial conducted in patients receiving AI and palbociclib as first line therapy for metastatic ER +HER2- breast cancer. 1000 patients will be included and treated with palbociclib in combination with an AI. Patients will be screened for circulating blood ESR1 mutation detection at regular intervals. Patients for whom a rising circulating ESR1 mutation is detected without tumour progression (up to N=200) will be randomised (1:1) between (1) Arm A: no modification of therapy; and (2) Arm B: palbociclib in combination with fulvestrant, a selective ER down-regulator. At tumour progression, an optional crossover will be offered to patients randomised in arm A. The coprimary endpoints are (1) Grade ≥3 haematological toxicities and their associations with baseline characteristics and (2) progression-free survival in randomised patients.

ETHICS AND DISSEMINATION

The study has been approved by the French medicines agency (ANSM) and by an ethics committee (ref 01/17_1 CPP Ouest-IV Nantes) in January 2017. The trial results will be published in academic conference presentations and international peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

EudraCT: 2016-004360-18; NCT03079011.

Abstract GS2-01: Overall survival subgroup analysis by metastatic site from the phase 3 MONALEESA-2 study of first-line ribociclib + letrozole in postmenopausal patients with advanced HR+/HER2− breast cancer

Background: MONALEESA-2 (ML-2) recently reported a statistically significant overall survival (OS) benefit with first-line ribociclib (RIB) + letrozole (LET) over placebo (PBO) + LET in postmenopausal patients with HR+/HER2- advanced breast cancer (ABC) (median, 63.9 vs 51.4 months; hazard ratio, 0.76; 95% CI, 0.63-0.93; P = .004). Understanding OS outcomes in clinically relevant subgroups of patients is important for improving personalized care and prognosis. Here, we report the results of a prespecified exploratory OS analysis in select patient subgroups by baseline location and number of metastatic sites.. Methods: Postmenopausal patients with HR+/HER2− ABC were randomized 1:1 to receive first-line RIB or PBO with LET. Prespecified exploratory OS analyses were performed for subgroups of special interest by baseline location (bone only [yes or no], liver involvement [yes or no], liver or lung involvement [yes or no]) and number of metastatic sites (&lt; 3 or ≥ 3). The data are hypothesis generating since this analysis was exploratory and not powered for statistical significance.. Results: A total of 668 patients were included in the analysis. A consistent improvement in OS was observed with RIB + LET vs PBO + LET in all subgroups regardless of baseline metastatic site (Table). RIB + LET demonstrated an OS benefit over PBO + LET in clinically relevant subgroups by baseline location and number of metastatic sites, including subgroups of patients with liver metastases, liver or lung metastases, and ≥ 3 metastatic sites, who generally have a worse prognosis.. Conclusion: Consistent with the intent-to-treat population of ML-2, the results of this prespecified exploratory analysis demonstrated an OS benefit with RIB + LET independent of the site and number of metastatic lesions.

TableTreatment Arm (n)HR (95% CI)Bone-only metastasisYesRIB + LET (69)0.78 (0.50-1.21)PBO + LET (79)NoRIB + LET (265)0.77(0.61-0.96)PBO + LET (255)Liver involvementYesRIB + LET (59)0.81 (0.54-1.24)PBO + LET (72)NoRIB + LET (275)0.77 (0.62-0.97)PBO + LET (262)Liver or lung involvementYesRIB + LET (182)0.81(0.62-1.05)PBO + LET (190)NoRIB + LET (152)0.71 (0.53-0.96)PBO + LET (144)No. of metastatic sites&lt; 3RIB + LET (220)0.78(0.61-1.00)PBO + LET (222)≥ 3RIB + LET (114)0.71(0.51-0.98)PBO + LET (112)

Citation Format: Joyce O'Shaughnessy, Salomon M Stemmer, Howard A Burris, Yoon-Sim Yap, Gabe Sonke, Lowell Hart, Mario Campone, Katarina Petrakova, Eric P Winer, Wolfgang Janni, Pierfranco Conte, David A Cameron, Fabrice André, Carlos Arteaga, Juan Pablo Zarate, Arunava Chakravartty, Tetiana Taran, Fabienne Le Gac, Paolo Serra, Gabriel N Hortobagyi. Overall survival subgroup analysis by metastatic site from the phase 3 MONALEESA-2 study of first-line ribociclib + letrozole in postmenopausal patients with advanced HR+/HER2− breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-01.

Abstract GS2-00: Correlative analysis of overall survival by intrinsic subtype across the MONALEESA-2, -3, and -7 studies of ribociclib + endocrine therapy in patients with HR+/HER2− advanced breast cancer

Background: The MONALEESA (ML)-2, -3, and -7 trials have shown a significant benefit in overall survival (OS) with ribociclib (RIB) + endocrine therapy (ET) over placebo (PBO) + ET in HR+/HER2− advanced breast cancer. HR+ breast cancer is a clinically and biologically heterogeneous disease, with identified intrinsic subtypes that vary in incidence, survival rate, and response to treatment. In a pooled analysis of the ML studies, patients with both luminal and HER2-enriched (HER2E) subtypes exhibited a consistent progression-free survival benefit with RIB + ET. The HER2E subtype (RIB, 14%; PBO, 11%), which is associated with ET resistance and poor outcomes, exhibited the greatest relative reduction in risk of progression or death (61%) with RIB + ET. Here, we report a pooled analysis of the ML-2, -3, and -7 trials, presenting OS by intrinsic subtype.. Methods: Tumor samples from patients enrolled in the ML-2, -3, and -7 trials underwent PAM50-based subtyping (blinded from clinical data), and the correlation between intrinsic subtype and OS was analyzed. Gene expression profiling of formalin-fixed, paraffin-embedded tumor samples was performed using a customized NanoString nCounter GX 800-gene panel. The prognostic and/or predictive relationship between PAM50-based subtypes and OS was evaluated using univariable and multivariable Cox proportional hazards models. Multivariable models were adjusted for known clinical prognostic factors, including age, prior chemotherapy, prior ET, ECOG performance status, visceral disease (presence of liver/lung metastases), bone-only metastases, histological grade, number of metastatic sites, tumor type, and de novo metastatic disease.. Results: From the pooled patient population (N = 2066), 997 tumor (71% primary) samples from the RIB (n = 585) and PBO (n = 412) arms of the ML trials (ML-2, n = 318; ML-3, n = 414; ML-7, n = 265) were profiled. Subtype distribution was consistent across treatment arms (Table). A similar benefit with RIB vs PBO was observed in the ITT (hazard ratio [HR], 0.76; 95% CI, 0.67-0.86) and biomarker (HR, 0.75; 95% CI, 0.63-0.89) populations. In both univariable and multivariable analyses, intrinsic subtype was prognostic for OS in both the RIB and PBO arms (P &lt; .0001 for both arms); patients with luminal A subtype had the best OS outcomes in both arms, whereas patients with basal-like subtype had the worst OS outcomes. Intrinsic subtype was also predictive of OS (subtype-treatment interaction: P = .016 [univariable], P = .007 [multivariable]) with a consistent OS benefit with RIB treatment in all subtypes except for basal-like (Table). Patients with HER2E (HR, 0.60; P = .018), luminal B (HR, 0.69; P = .023), and luminal A (HR, 0.75; P = .021) subtypes all derived benefit from RIB. In patients with the basal-like subtype (n = 30), the HR was 1.89 (P = .148); these results should be interpreted with caution due to the small sample size (3% in each arm) and exploratory nature of this analysis.Conclusions: This pooled analysis of the ML trials confirmed the prognostic and predictive value of intrinsic subtype (PAM50 based) for OS. The addition of RIB to ET resulted in consistent OS benefit across all subtypes except for basal-like. The. consistent survival benefit in the HER2E subtype, which is associated with endocrine resistance and a very poor prognosis compared with luminal disease, warrants further investigation.

SubtypeTreatment ArmDistribution, n (%)OS, median (95% CI), monthsHR (95% CI)P ValueaLuminal ARIB320 (55)68.0 (61.5-NR)0.75 (0.58-0.96).021PBO222 (54)54.6 (48.3-66.2)Luminal BRIB154 (26)58.8 (48.3-79.2)0.69 (0.50-0.95).023PBO124 (30)44.9 (35.5-52.6)HER2-enrichedRIB95 (16)40.3 (33.4-49.0)0.60 (0.40-0.92).018PBO52 (13)29.4 (23.9-42.0)Basal-likeRIB16 (3)19.4 (10.7-33.2)1.89 (0.80-4.47).148PBO14 (3)21.2 (12.8-NR)aP values are all two-sided. NR, not reached.

Citation Format: Lisa Carey, Nadia Solovieff, Fabrice André, Joyce O'Shaughnessy, David A Cameron, Wolfgang Janni, Gabe S Sonke, Yoon-Sim Yap, Denise A Yardley, Juan Pablo Zarate, Tetiana Taran, Faye Su, Agnes Lteif, Aleix Prat. Correlative analysis of overall survival by intrinsic subtype across the MONALEESA-2, -3, and -7 studies of ribociclib + endocrine therapy in patients with HR+/HER2− advanced breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-00.

Abstract P3-19-01: CANTO RT: The largest prospective multicenter cohort of early breast cancer patients treated with radiotherapy including full DICOM RT data

Purpose: In this paper, we describe the methodology used, and provide a first characterization of the study population and radiotherapy (RT) data in CANTO-RT (CANcer TOxicities Radiotherapy), the largest available multicenter prospective cohort of early breast cancer (BC) patients treated with RT that aims to identify predictors of development, and persistence of long-term toxicities. Methods: CANTO (NCT01993498) is a French prospective clinical cohort study of 10 150 patients with stage I-III BC from 26 cancer centers. Patients matching all CANTO inclusion and exclusion criteria, who received RT and were still in follow up, in the 10 top recruiting CANTO centers, with a minimum follow up of 3 years, were selected for CANTO-RT. Eligible patients had breast/chest wall +/- lymph node RT with curative intent. Individual full DICOM RT files (CT, RT Structure, RT Dose, RT Plan) were collected, anonymized, structured and analyzed on the CANTO-RT/UNITRAD web platform using AQUILAB Share Place™ and Analytics Dose module. Characteristics of the patients and tumors (including TNM, histology, HER2, estrogen and progesterone receptor) were recorded at baseline. Characteristics of the treatments, skin, lung, cardiovascular, neurological, musculoskeletal toxicities (CTCAE v4.0), QOL (BR23, QLQC30), cosmetic, and oncological outcomes were assessed at diagnosis (baseline), 3-6 (M0), 12 (M12), 36 (M36) and 60 (M60) months after completion of primary surgery, chemotherapy or radiotherapy whichever came last together, with blood, plasma and serum tests. Results: CANTO-RT enrolled 3875 BC patients between June 2012 and February 2017 with a median follow-up of 64 months :1947 (50.2%) left side, 1850 (47.8%) right side and 78 (2%) bilateral BC. The vast majority of patients had hormone receptor-positive tumors 3321 (85.7%) and 553 (14.3%) had human epidermal growth factor 2 (HER2) positive tumors; 2586 (66.7%) had stage pT1 and 2525 (65.2%) pN0 disease; 2087 (53.8%) neoadjuvant or adjuvant chemotherapy, 477 (12.3%) adjuvant trastuzumab and 3138 (81%) adjuvant endocrine therapy. Among 3797 patients with unilateral RT, 3065 (80.4%) had breast conserving surgery, 747 (19.6%) total mastectomy; 2712 (71.5%) sentinel node and 1080 (28.5%) axillary dissection. Tumor bed boost was delivered in 2658 patients (68.5%) and lymph node RT in 1356 patients (35%) including internal mammary chain in 844 patients (21.8%). Most patients 3691 (95.3%) were treated with 3D conformal RT and 184 (4.7%) with intensity-modulated RT. Normofractionated RT (2Gy/fraction) was mostly used (69.9%). Clinical target (breast, chest wall, lymph nodes) and contoured organs at risk (heart, left anterior descending coronary, lung, spinal cord, esophagus, thyroid, brachial plexus, contralateral breast, humeral head) contours and dose/volume histograms were automatically extracted after quality control procedure excluding corrupted files and inconsistencies 36 (1%) (Table 1). Conclusion: CANTO-RT is the largest early breast cancer prospective cohort with full individual clinical and DICOM RT data available. CANTO-RT is a valuable resource, open for collaborative projects, for identification and validation of clinical and dosimetric predictive factors of RT related toxicities. Further long term follow up is ongoing.

Table 1.Baseline characteristics of the CANTO RT breast cancer patients.CharacteristicsBreast Cancer Patients [N(%) or Mean (range)]Age at enrolmentMean (range), years56.5 (23.3-85.8)Tumour size (pT)T037 (1)T12586 (66.7)T21058 (27.3)T3177 (4.6)Missing17 (0.4)Nodal status (pN)02525 (65.2)11035 (26.7)2223 (5.8)379 (2)Missing13 (0.3)Tumour histologyInfiltrating Ductal3011 (77.7)Lobular473 (12.2)Others (including mixed)381 (9.8)Missing10 (0.3)Hormone Receptors positiveNegative541 (14)Positive3321 (85.7)Missing13 (0.3)HER2Negative3305 (85.3)Positive553 (14.3)Missing17 (0.4)Type of chemotherapyNo chemotherapy1788 (46.1)Neoadjuvant chemotherapy450 (11.6)Adjuvant chemotherapy1629 (42)Peri-adjuvant chemotherapy (neo + adjuvant)8 (0.2)Hormonal therapyNo730 (18.8)Yes3138 (81)Missing7 (0.2)Herceptin treatmentNo or Not applicable3378 (87.2)Yes477 (12.3)Missing20 (0.5)Type of breast surgerylumpectomy3113 (80.3)Mastectomy734 (18.9)Right lumpectomy and Left mastectomy13 (0.3)Right mastectomy and Left lumpectomy9 (0.2)None6 (0.2)Type of lymph node surgerySentinel node2746 (70.9)Axillary dissection1086 (28)Right sentinel node, Left axillary dissection20 (0.5)Right axillary dissection, left sentinel node12 (0.3)None11 (0.3)Radiation therapyRight Side1850 (47.8)Left Side1947 (50.2)Bilateral78 (2.0)Patients with boostNo or Not applicable1217 (31.4)Yes2658 (68.6)Lymph node levels treatedNone2519 (65)Yes1356 (35)Level 1284 (20.9)Level 2340 (25.1)Level 31072 (79.1)Level 41348 (99.4)Internal mammary chain844 (62.2)Irradiation techniques3D3691 (95.3)IMRT184 (4.7)Fractionation regimensNormofractionation 25-fractions2707 (69.9)Hypofractionation 15-16 fractions166 (4.3)Hypofractionation and Partial breast irradiation51 (1.3)Unspecified fractionation - CTV breast or chest wall not delineated951 (24.5)

Citation Format: Thomas Sarrade, Rodrigue Allodji, Youssef Ghannam, Guillaume Auzac, Sibille Everhard, Ophélie Querel, Youlia Kirova, Karine Peignaux, Philippe Guilbert, Claire Charra-Brunaud, Julien Blanchecotte, Rezart Belshi, David Pasquier, Séverine Racadot, Céline Bourgier, Sandrine Ducornet, David Gibon, Fabrice André, Florent De Vathaire, Sofia Rivera. CANTO RT: The largest prospective multicenter cohort of early breast cancer patients treated with radiotherapy including full DICOM RT data [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-01.

Abstract PD8-02: Trastuzumab deruxtecan (T-DXd) for advanced breast cancer patients (ABC), regardless HER2 status: A phase II study with biomarkers analysis (DAISY)

Background: The HER2-targeted antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) demonstrated efficacy in heavily pretreated HER2-over- and HER2-low expressing ABC (1, 2). We aimed to assess the activity of T-DXd in HER2-over-, HER2-low and HER2-nul expressing ABC, to describe the drug mechanisms of action in the 3 cohorts and to identify biomarkers associated to drug response or resistance. Study Description: DAISY is a multicenter, open-label phase II trial designed to assess the efficacy of single agent T-DXd at 5.4 mg/kg dose in ABC with extensive biomarkers analysis. Three cohorts of patients were included: Cohort 1 (HER2 over-expressing: HER2 3+ on immunohistochemistry (IHC) or HER2 IHC2+/in situ hybridization [ISH]+), Cohort 2 (HER2 low-expressing: IHC1+ or IHC2+/ISH-) and cohort 3 (HER2-nul: IHC0+). Biopsy of metastatic sites was performed: at baseline, on treatment (mandatory for cohort 1, optional for cohort 2/3) and at tumor progression; blood samples for ctDNA were collected at baseline. The primary endpoint was the Best Overall Response (BOR) in each cohort, according to the investigator assessment. Secondary endpoints were BOR by central assessment, clinical benefit rate, duration of response (DOR), progression-free (PFS), overall survival (OS) and safety. Results:185 women and 1 man were enrolled between November 2019 and March 2021. Among the patients enrolled in the safety population (see Table 1), median (range) age was 55 (24-82) years, all received at least one prior line of therapy and 12 patients were TN. Table 2 shows investigator-reported T-Dxd activity in the 3 cohorts at a median follow-up of 10.1 months [95%CI: 9.2-11.1]. A total of 170 patients (95%) had at least one treatment-related toxicity. Key grade ≥3 treatment-related toxicities included neutropenia (10.6% of patients), fatigue (5.6%), leucopenia (4.5%), vomiting (4.5%) and anemia (3.4%). A total of 4 patients had drug-related interstitial lung disease or pneumonitis (grade 1 in 3 patients and grade 2 in 1 patient), 11 patients discontinued treatment due to treatment-related adverse events. No drug-related deaths occurred. Conclusions: T-DXd showed clinically meaningful activity in patients with HER2-overexpressing ABC and interestingly also in those with HER2low and HER2-nul ABC. Safety profile was consistent with previous reports. 1.Modi S et al N Engl J Med 2020 2.Mosi S et al J Clin Oncol 2020

Table 1.Analysis populationsTotalCohort 1 (HER2 over-expressing)Cohort 2 (HER2 low-expressing)Cohort 3 (HER2 non-detected)Enrolled population186727440Safety population*179687338 (including 12 TN)Full analysis Set**176687236TN: Triple Negative. *: safety population = enrolled population except 7 patients who did not receive at least one dose of study drug. **: Full Analysis Set = safety population except 3 patients (2 who did not have a valid first post-baseline assessment of disease status or who did not have progressive disease and 1 who did not have at least one radiologically measurable lesion according to RECIST v1.1)

Table 2.T-DXd activity in the three cohorts according to investigator assessmentTotalCohort 1Cohort 2Cohort 3BOR confirmedn/N82/176 (46.6%)47/68 (69.1%)24/72 (33.3%)11/36 (30.6%)[95%CI][39.1; 54.2][56.7; 79.8][22.7; 45.4]16.3; 48.1]Median DORmonths7.69.97.66.8[95%CI][6.2; 9.7][5.4; NR][4.4; 8.7][2.8; 8.3]Median PFSmonths6.911.16.74.2[95%CI][6.7; 8.7][8.4; NR][4.6; 8.5][2.1; 6.9]NR: Not Reached

Citation Format: Véronique Diéras, Elise Deluche, Amélie Lusque, Barbara Pistilli, Thomas Bachelot, Jean-Yves Pierga, Frédéric Viret, Christelle Levy, Laura Salabert, Fanny Le Du, Florence Dalenc, Christelle Jouannaud, Laurence Venat-Bouvet, Jean-Philippe Jacquin, Xavier Durando, Thierry Petit, Céline Mahier - Aït Oukhatar, Thomas Filleron, Maria Fernanda Mosele, Magali Lacroix-Triki, Agnès Ducoulombier, Fabrice André. Trastuzumab deruxtecan (T-DXd) for advanced breast cancer patients (ABC), regardless HER2 status: A phase II study with biomarkers analysis (DAISY) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD8-02.

Abstract PD10-05: Activity of atezolizumab (atezo) plus paclitaxel (pac) in metastatic triple-negative breast cancer (mTNBC) according to Burstein molecular subtype: Analysis of the IMpassion131 trial

Background: In contrast to the IMpassion130 trial evaluating atezo + nab-pac [Schmid, NEJM 2018], the randomized phase 3 IMpassion131 trial (NCT03125902) did not demonstrate significantly improved progression-free survival (PFS; primary endpoint) and showed no improvement in overall survival (OS; secondary endpoint) with the addition of atezo to pac as first-line therapy for mTNBC in either the PD-L1+ or the intention-to-treat (ITT) population [Miles, Ann Oncol 2021]. In IMpassion130, enhanced PFS and OS improvement with atezo + nab-pac were seen in the basal-like immune-activated (BLIA) subtype, whereas potential resistance to atezo + nab-pac was observed in the luminal androgen receptor (LAR) subtype [Emens, ASCO 2021]. LAR may be more prevalent in Asian populations [Ding, Oncotarget 2019], which represented one-third of patients enrolled in IMpassion131 and could have influenced the overall result. PFS outcomes were numerically worse in Asian vs non-Asian subgroups in IMpassion131 [Miles, Ann Oncol 2021]. To investigate potential reasons for observing different effects in IMpassion130 and IMpassion131, we explored the prevalence and impact on clinical outcomes of TNBC molecular subtypes and race in IMpassion131. Patients and Methods: Patients with mTNBC (no prior systemic therapy or ≥12 months since [neo]adjuvant chemotherapy) were randomized 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m2 (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity, stratified by tumor PD-L1 status, prior taxane, liver metastases, and geographic region. Molecular subtypes according to Burstein classification were determined by RNA sequencing (Illumina TruSeq RNA Access) of baseline tumor samples. Prevalence of Burstein molecular subtypes [Burstein, Clin Cancer Res 2015] was assessed in Asian (of whom 69% were enrolled in China) and non-Asian populations; clinical outcomes were assessed according to molecular subtype and race using Cox proportional hazards analysis. All analyses were performed using the final data cut-off (Sep 4, 2020; median follow-up duration: 14.4 months). Results: The biomarker-evaluable population (BEP; n=471) was representative of the ITT population (n=651) with respect to baseline characteristics and PFS hazard ratio (HR; 0.75 [95% CI 0.61-0.92] vs 0.81 [95% CI 0.68-0.96], respectively). Distribution of molecular subtypes in the BEP was: 30% BLIA, 41% basal-like immune suppressed (BLIS), 24% LAR, 5% mesenchymal (MES), similar to IMpassion130. Among the BLIA samples, 82% were PD-L1+ and 18% PD-L1-; corresponding percentages were 41% vs 59% for BLIS, 31% vs 69% for LAR, and 32% vs 68% for MES. Compared with non-Asian patients, the Asian subgroup (n=117) included more LAR (31% vs 22%) and fewer MES (1% vs 6%) samples; this was particularly pronounced in the cohort enrolled in China (n=79; 37% LAR, 0% MES). PFS was improved with atezo + pac in the BLIA subtype (HR 0.66, 95% CI 0.45-0.97). None of the Burstein subgroups derived OS benefit from atezo + pac. Findings were similar irrespective of PD-L1 status. Direction of effect for PFS and OS favored the placebo + pac arm in the LAR Asian subgroup (n=30). Conclusion: In these exploratory analyses, the distribution of molecular subtypes and enhanced effect of atezo + pac in the BLIA subtype are consistent with findings from IMpassion130. The lack of improved efficacy with the combination of atezo + pac in the IMpassion131 trial cannot be explained by overrepresentation of a Burstein subtype less sensitive to atezo in the trial population.

Citation Format: Fabrice André, Regula Deurloo, Aditi Qamra, David Cameron, Joseph Gligorov, Andreas Schneeweiss, Carlos Barrios, Binghe Xu, Ching-Wei Chang, Luciana Molinero, Shilpen Patel, Andrea Liptrot, Leilani Morales, David Miles, Joyce O’Shaughnessy. Activity of atezolizumab (atezo) plus paclitaxel (pac) in metastatic triple-negative breast cancer (mTNBC) according to Burstein molecular subtype: Analysis of the IMpassion131 trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD10-05.

Abstract P4-11-01: Development of a clinico-bio-behavioral model for cancer-related fatigue (CRF) incorporating inflammatory biomarkers and proteomic data

Background: We previously developed a clinico-behavioral model of CRF and reported an increased risk of severe CRF among survivors of breast cancer (BC) receiving adjuvant hormonal therapy (HT) (Di Meglio A, ASCO 2021). We now aim to comprehensively explore the contribution of relevant serum proteins in explaining CRF. We adopted a multimodal approach, both (1) hypothesis-driven, based on the rationale that deregulation of systemic inflammatory processes and mediators of immunologic or neuroendocrine activation are associated with vulnerability to CRF, and (2) discovery-driven, based on proteomic analyses. Methods: Women with stage I-III HR+/HER2- tumors receiving HT (N=1153) were included from the multicenter, prospective CANTO cohort (NCT01993498). The primary outcome of interest was severe post-treatment global CRF at year-2 (Y2) after diagnosis (score ≥ 40/100, EORTC QLQ-C30). Secondary outcomes included CRF dimensions (physical, emotional, cognitive; EORTC QLQ-FA12). For the hypothesis-driven analyses, pre-treatment blood samples were profiled (Randox Laboratories Limited, UK) at diagnosis of BC, using a multi-biomarker panel assessing IL6, TNFα, IL1RA, CRP, IL2, IL1β, IFNγ, IL10, IL1A, IL4, and IL8. Pre-specified pre-treatment clinico-behavioral covariates (age, BMI, smoking status, psychological, and pre-treatment symptom burden, based on previously developed models) were forced into a multivariable logistic regression. Biomarkers were retained by Augmented Backwards Elimination (p&lt;0.05) only if significantly associated with CRF. For the discovery approach, we used hyper-reaction monitoring mass spectrometry for the unbiased quantification of all detectable peptides and proteins in human plasma samples at diagnosis (Biognosys, CH), among a discovery subset (N=462). We then aimed to identify a proteomic signature associated with severe CRF at Y2. Log-transformed protein intensities were analyzed in terms of differential expression. The proteins that were identified to be significantly different among the patients reporting and not reporting severe CRF were then used to train a logistic regression model. Results: Prevalence of severe global CRF increased from 21.6% at diagnosis to 34.8% at Y2. In the final model, higher pre-treatment levels of IL6 and lower levels of IFNγ and IL10 were significant predictors of severe global CRF at Y2 (Table). The AUC of this clinico-bio-behavioral model was 0.78 (95%CI 0.75 - 0.82) and was suggestive of an improved performance as compared to clinico-behavioral models. Among CRF dimensions, a significant association emerged only between CRP and severe cognitive CRF (outcome prevalence at Y2 14.2%; adjusted OR per CRP log-unit increase 1.40 [95%CI 1.01-1.93]).

In the discovery subset, several proteins were identified as differentially regulated (p&lt;0.05) among patients reporting and not reporting severe CRF at Y2. Most of these were related to coagulation pathways (including C4BPA, C4BPB, HABP2, PLF4, PROS). However, models incorporating proteomic data did not seem to augment the predictive ability compared to clinico-behavioral models. Conclusions: Using clinical and biological pre-treatment measurements, it may be possible to identify a subset of BC patients at high risk for increased post-treatment CRF while on HT. This provides the possibility of testing dedicated preventive interventions.

Table. Clinico-bio-behavioral model of pre-treatment predictors of severe global CRF at Y2, incorporating circulating inflammatory biomarkers.Adjusted OR§ (95% CI)Age, per additional 1 year0.98 (0.96-0.99)BMI, per additional unit1.02 (0.99-1.06)Current smoker, vs never2.27 (1.47-3.51)Former smoker, vs never0.97 (0.64-1.46)Anxiety case*, vs normal1.13 (0.75-1.70)Doubtful anxiety*, vs normal1.11 (0.73-1.68)Pre-treatment Insomnia**, per additional 10 points1.09 (1.04-1.15)Pre-treatment Pain**, per additional 10 points1.10 (1.01-1.18)Severe pre-treatment CRF**, vs no4.70 (3.13-7.05)IL6***1.72 (1.25-2.36)IL1RA***1.24 (0.85-1.81)IL2***1.43 (0.99-2.08)IFNγ***0.54 (0.30-0.95)IL10***0.40 (0.18-0.87)IL4***1.47 (0.67-3.20)IL8***1.15 (0.83-1.60)OR= Odds Ratio; CI= Confidence Interval; §by all factors in Table; *HADS; **QLQ-C30; ***per log-unit increase

Citation Format: Antonio Di Meglio, Stergios Christodoulidis, Davide Soldato, Antonin Della Noce, Daniele Presti, Julie Havas, Florine Dubuisson, Barbara Pistilli, Valerie Camara-Clayette, Cecile Charles, Patricia A Ganz, Julienne Bower, Ann H Partridge, Alexandra Jacquet, Sibille Everhard, Sandrine Boyault, Fabrice André, Paul-Henry Cournede, Stefan Michiels, Caroline Pradon, Ines Vaz-Luis. Development of a clinico-bio-behavioral model for cancer-related fatigue (CRF) incorporating inflammatory biomarkers and proteomic data [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-01.

Abstract P4-11-34: An integrated clinical, behavioral and biological model to predict the risk of weight gain among breast cancer survivors (BCS)

Background: Weight management is an integral part of survivorship care. Excess weight in BCS is associated with worse clinical outcomes and quality of life. Early identification of BCS at risk of gaining substantial weight could lead to prompt and tailored interventions. We aimed at developing a predictive model of weight gain that integrates clinical, behavioral and biological data. Methods: We included patients with stage I-III BC from the CANTO cohort (NCT01993498). CANTO collects longitudinal data, including objective anthropometric measures, at diagnosis (dx), 1 (T1), 2 (T2) and 4 (T3) years after dx. In addition, profiling of blood samples obtained at dx was performed for two sub-cohorts with HR+/HER2- BC for quantification of: (1) inflammatory and metabolic biomarkers (IL6, TNFα, IL1RA, CRP, IL2, IL1β, IFNγ, IL10, IL1A, IL4, IL8, ADPN, LEPT, INS, RETN) and (2) detectable proteins using hyper reaction mass spectrometry (Biognosys). Our outcome of interest was weight gain (increase ≥ 5%) compared to dx. First, multivariable logistic regression with bootstrapped Augmented Backwards Elimination (ABE) retained associations between weight gain and clinico-behavioral covariates. To assess contribution of biologic data, ABE retained associations between weight gain and biomarkers, correcting for significant covariates. Models were validated using internal cross-validation and overoptimism-correction. For proteomics, proteins relative intensity was calculated, and a bootstrapped differential protein expression analysis identified proteins associated with weight gain that were then included in logistic regression. Models performance was assessed in terms of Area Under the Curve (AUC). Results: In the overall cohort (N=9541) mean age was 56.8 (SD 11.4), mean BMI was 25.9 Kg/m2 (SD 5.4), 48.9% of pts were overweight or obese, and 52.9% received chemotherapy (CT). Overall, 16.9% (T1), 23.4% (T2), and 27.2% (T3) BCS gained weight (absolute mean change (95% CI): 6.1 kg (5.9-6.2), 6.7 kg (6.5-6.9) and 7.2 kg (6.9-7.3) at T1, T2, T3, respectively). In clinico-behavioral models, younger age, current smoking, lower income and education, receipt of CT and radiotherapy were associated with increased risk of weight gain (Table). Among 1261 BCS with biomarkers data, higher levels of IL1α (OR for 1-unit log increase [95%CI] 0.11 [0.02 - 0.65]) and of ADPN (1.36 [1.01 - 1.85]) were associated with lower and higher risk of weight gain at T2 and T3, respectively. Performance of models integrating these biomarkers was similar to clinico-behavioral models. Among 462 BCS with proteomic profiling, preliminary data showed that higher relative abundance of IgG Fc Binding Protein (OR 0.44, p&lt;.05) and Tubulin-1 (OR 0.73, p&lt;.05) was associated with lower risk of weight gain at T1. AUC of model integrating clinical and proteomics data was 0.74 (0.58-0.90). Conclusions: Over one-in-four BCS in the CANTO cohort experienced meaningful weight gain 4 years after dx. This large, multidimensional study confirms the role of clinico-behavioral risk factors for weight gain. However, the predictive ability of clinico-behavioral models seems suboptimal. The exploitation of additional data dimensions, including serum proteins and proteomic data, may help improve predictive ability and inform underlying biological processes implicated in weight gain after BC. Further studies will aim at improving model stability, particularly for proteomics analyses.

Table. Models of weight gain in the overall cohort.T1 (N= 8397)T2 (N= 7663)T3 (N= 5802)Clinical predictors OR* (95% CI)OR* (95% CI)OR* (95% CI)Age, 1-year increase0.96 (0.94 - 0.97)0.96 (0.95 - 0.97)0.96 (0.95 - 0.97)BMI, 1-unit increaseNRNS0.97 (0.94 - 0.99)Education, primary vs collegeNS1.57 (1.04 - 2.39)NREducation, high school vs college1.38 (1.04 - 1.83)1.54 (1.21 - 1.98)NRIncome, ≥ 1500 and &lt;3000 vs &gt;3000NRNR1.29 (1.00 - 1.66)Smoke, current vs never1.70 (1.24 - 2.33)NR1.53 (1.12 - 2.08)Chemotherapy, yes vs no1.40 (1.07 - 1.82)1.31 (1.01 - 1.69)NRRadiotherapy, yes vs no2.10 (1.10 - 3.99)NR1.83 (1.08 - 3.12)AUC (95% CI) - clinical models0.65 (0.63 - 0.68)0.64 (0.61 - 0.67)0.65 (0.63 - 0.68)AUC (95% CI) - clinical + inflammatory and metabolic biomarkers models, [N]0.65 (0.60 - 0.70), [1179]0.66 (0.62 - 0.70), [948]0.67 (0.63 - 0.71), [1017]AUC (95% CI) - clinical and proteomics models, [N]0.74 (0.58 - 0.90), [462]0.65 (0.50 - 0.81), [462]NEOR= Odds Ratio, CI= Confidence Interval, NR= Not Retained, NS= Not significant, NE= Not evaluated *Adjusted by age, menopause, smoke, socioeconomic, psychological, tumor and treatments **Significant covariates from previous models were forced and ABE selected significant variables among all circulating biomarkers.

Citation Format: Davide Soldato, Antonio Di Meglio, Caroline Pradon, Antonin Della Noce, Daniele Presti, Julie Havas, Florine Dubuisson, Barbara Pistilli, Valerie Camara-Clayette, Fabrice André, Alexandra Jacquet, Sibille Everhard, Sandrine Boyault, Paul-Henry Cournede, Stefan Michiels, Ines Vaz-Luis, Stergios Christodoulidis. An integrated clinical, behavioral and biological model to predict the risk of weight gain among breast cancer survivors (BCS) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-34.

Abstract P4-07-17: Association between plasma-based sequential windowed acquisition mass spectrometry (SWATH-MS) and invasive disease free survival (iDFS) in HR+/HER2- early breast cancer in the CANTO cohort

Background: The definition of breast cancer (BC) prognosis has historically relied on clinico-pathological factors. Novel omics markers including proteomic analyses could improve our understanding of the biological host drivers of breast cancer recurrence and survival. We aimed at identifying patients (pts) at high risk of recurrence based on proteomic markers in plasma.Methods: CANTO is a multicenter, prospective cohort study of stage I-III BCS (NCT01993498). Plasma samples were collected on HR+/HER2- pts at diagnosis (dx) and analyzed by SWATH-MS, implemented by Biognosys AG (Schlieren, Switzerland), resulting in a relative quantification of the abundance of 500 proteins in the plasma. A Cox model was fitted to estimate to associate proteomic and clinical variables with the primary endpoint IDFS Clinical covariates consisted of age, stage and grade. An adaptive Lasso method was used to perform model selection. The discrimination performances of the model were assessed on 100 random train-test partitions of the cohort. Results: There were 457 pts with analyzed plasma samples. The median age at dx was 59.3 years, and the repartition of cancer stage was 52% for stage I, 37% for stage II and 11% for stage III. The mean duration of follow-up was 5.4 years, and 53 (11.5%) IDFS events (non local recurrences, second primary cancers and deaths) were reported. In total, 7 proteins were selected by the adaptive Lasso process; associated with the age, the stage and the grade at dx, 3 proteins were retained as having a significant impact on the IDFS: GTP-binding nuclear protein Ran (RAN), involved in cell division and GTP metabolic process, C4b-binding protein alpha-chain (C4BPA), involved in complement activation, and prothrombin (THRB), involved in acute-phase response and blood activation. Concordance indices were computed on 100 random test subsets of the cohort for the model with clinical variables only (0.67+/- 0.08), for the model with selected protein features only (0.74 +/- 0.07) and for the model with both proteomic and clinical covariates (0.75 +/-0.06). Conclusion: The discrimination performances of the estimated model suggest that proteomics provide relevant markers associated with BC prognosis. Validation on an independent validation set is required. Host related plasma proteins represent an avenue worth exploring to improve our understanding of BC relapse risk

Table 1.Estimated hazard ratios of the linear Cox model.FeaturesHR* (95% CI)p-valuesRAN (for 1 SD increase)0.66 (0.51-0.85)&lt;0.005THRB (for 1 SD increase)1.43 (0.99-2.06)0.05C4BPA (for 1 SD increase)1.44 (1.02-2.02)0.04stage--II vs I1.68 (0.82-3.46)0.16III vs I4.29 (1.88-9.75)&lt;0.005HR = hazard ratio CI = confidence interval * adjusted by age and grade

Citation Format: Antonin Della Noce, Stergios Christodoulidis, Antonio Di Meglio, Julie Havas, Alicia Tran-Dien, Fabrice André, Ines Vaz-Luis, Paul-Henry Cournède, Stefan Michiels. Association between plasma-based sequential windowed acquisition mass spectrometry (SWATH-MS) and invasive disease free survival (iDFS) in HR+/HER2- early breast cancer in the CANTO cohort [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-07-17.

Abstract OT2-11-06: SERENA-4: A Phase III comparison of AZD9833 (camizestrant) plus palbociclib, versus anastrozole plus palbociclib, for patients with ER-positive/HER2-negative advanced breast cancer who have not previously received systemic treatment for advanced disease

Background: More than two thirds of patients with advanced breast cancer (ABC) have estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2−) tumors. In most countries, current standard-of-care first-line treatments include an aromatase inhibitor or fulvestrant, a selective ER degrader, combined with cyclin-dependent kinase 4/6 inhibitors. Concurrent use of luteinizing hormone-releasing hormone agonists is recommended for men and premenopausal women with ABC. Nevertheless, almost all ABCs eventually become resistant to endocrine therapy and the disease is incurable in these cases. New therapies are needed to combat endocrine therapy resistance, maintain patient health-related quality-of-life, and delay the need for chemotherapy. AZD9833 (camizestrant) is a highly potent, next-generation selective ER degrader and pure ER antagonist that has demonstrated anticancer properties across a range of preclinical models, including those with ER-activating mutations (Scott et al, AACR 2020). A Phase I dose-escalation and expansion study (SERENA-1) has demonstrated that AZD9833 is well tolerated and has a promising antitumor activity when administered alone or in combination with the cyclin-dependent kinase 4/6 inhibitor palbociclib (Baird et al, SABCS 2020). SERENA-4 (NCT04711252) is a randomized, multicenter, double-blind, Phase III trial to evaluate the safety and efficacy of AZD9833 in combination with palbociclib for patients with ER+/HER2− ABC who have not received systemic treatment in the advanced disease setting. Methods: SERENA-4 will enroll 1342 patients with de novo or recurrent ER+/HER2− ABC who have not previously received systemic treatment for their locoregionally recurrent or metastatic disease. Patients with recurrent disease must have received adjuvant aromatase inhibitor or tamoxifen therapy for at least 24 months without relapse. Patients will be randomized 1:1 to receive oral treatment with either (a) AZD9833 75 mg once daily, palbociclib 125 mg once daily for 21 days followed by 7 days off treatment and a placebo for anastrozole 1 mg once daily or (b) anastrozole 1 mg once daily, palbociclib (same as active arm) and a placebo for AZD9833 75 mg once daily. Men and premenopausal women will also receive a luteinizing hormone-releasing hormone agonist. The primary endpoint is progression-free survival (PFS; up to 5 years). Secondary endpoints include overall survival (up to 8 years), second PFS, time to chemotherapy, objective response rate, and changes in health-related quality-of-life measures. Enrollment began in January 2021. As of 02 July 2021, the number of open sites is 57 across 15 countries. Acknowledgments: We thank Julia Mawer, PhD, of Oxford PharmaGenesis, Oxford, UK, for providing medical writing support funded by AstraZeneca Funding: The SERENA-4 trial is funded and overseen by AstraZeneca. © 2021 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2021 ASCO Annual Meeting. All rights reserved.

Citation Format: Fabrice André, Seock-Ah Im, Patrick Neven, Richard D Baird, Johannes Ettl, Matthew P Goetz, Erika Hamilton, Hiroji Iwata, Zefei Jiang, Anil Abraham Joy, Vincent Haddad, Andrew Walding, Manuel Selvi Miralles, Cynthia Huang Bartlett, Antonio Llombart-Cussac. SERENA-4: A Phase III comparison of AZD9833 (camizestrant) plus palbociclib, versus anastrozole plus palbociclib, for patients with ER-positive/HER2-negative advanced breast cancer who have not previously received systemic treatment for advanced disease [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT2-11-06.

Abstract P4-11-09: Cancer-related cognitive impairment (CRCI) in early breast cancer (BC) survivors

Background: Up to 35% BC survivors who receive adjuvant treatment (tx) experience severe CRCI, which has a significant impact on quality of life, disrupting daily functioning as well as self-esteem, self-confidence, and work ability. However, limited tools exist to predict the risk of CRCI. We aimed to develop a comprehensive model of severe CRCI, including clinical and serum inflammatory protein data. Methods: We included 8875 patients (pts) with stage I-III BC from the multicenter, prospective CANTO cohort (NCT01993498). Longitudinal data were collected at diagnosis (dx), 1 (T1), 2 (T2) and 4 (T3) years post-dx. Our outcome of interest was severe cognitive impairment at T1, T2, and T3 (score &lt; 75/100, EORTC QLQ-C30, Giesinger JM 2020). Multivariable logistic regression models retained associations between baseline clinical variables (sociodemographic, psychological, tumor, and tx-related) with severe CRCI by bootstrapped Augmented Backwards Elimination (ABE). Among a subset of patients with HR+/HER2- BC (N= 1151), blood samples were profiled at dx using a multi-biomarker inflammatory panel assessing IL6, TNFα, IL1RA, CRP, IL2, IL1β, IFNγ, IL10, IL1A, IL4, IL8, and monocyte chemoattractant protein-1 (MCP-1). All biomarkers were incorporated simultaneously into a model of severe CRCI and retained only if significantly associated with CRCI by ABE (p&lt;0.05). Previously retained clinical associations were forced into the model. Results: In the overall cohort, mean age at dx was 56.7 years (SD 11.3), and 52.7% and 81.3% of pts received chemotherapy and hormonal therapy, respectively. Prevalence rates of severe CRCI were 31.2% (dx), 31.4% (T1), 30.9% (T2), and 29.9% (T3). Severe post-tx CRCI was consistently associated with severe pre-tx pain and severe pre-tx CRCI. Severe pre-tx fatigue, younger age, anxiety symptoms and hot flashes at dx were also associated with increased odds of severe CRCI at some post-dx time-points (Table 1). Models Area Under the Curve (AUC) were 0.73 (95% confidence intervals [CI] 0.70-0.76) at T1, 0.69 (CI 0.65-0.72) at T2, and 0.68 (CI 0.63-0.72) at T3. Among pts with available serum biomarkers, no significant associations were observed between inflammatory proteins and CRCI at any time point. Performance of models incorporating inflammatory biomarkers was similar to clinical-only models (Table 2). Conclusions: Almost 1/3 of BC survivors in this cohort reported severe CRCI. This rate was stable throughout the survivorship period and did not seem to be affected by cancer-specific or tx-related factors, or inflammatory biomarkers. Pts age and concomitant symptom burden at dx emerged as consistent associations with severe CRCI. A description of the average population risk of CRCI using a self-reported, global evaluation scale may not fully describe the granularity of this phenomenon. Further studies building on dedicated, objective measurements, may help identify latent classes of pts experiencing a major decline in cognitive function following BC tx, and for whom a contribution of biology may help explain inter-individual variability and underlying biological processes.

Table 1.Models of severe CRCI in the overall cohort: clinical predictors.T1 (N=7724)T2 (N=6825)T3 (N=4706)OR* (95% CI)OR* (95% CI)OR* (95% CI)Severe Pain**, vs no1.50 (1.09-2.07)1.93 (1.39-2.69)1.55 (1.03-2.34)Severe pre-tx CRCI**, vs no3.69 (2.70-5.05)2.53 (1.85-3.46)2.21 (1.47-3.32)Severe Fatigue**, vs no1.50 (1.06-2.11)1.61 (1.13-2.28)1.08 (0.69-1.70)Age (continous)0.98 (0.97-0.99)NR0.98 (0.96-0.99)Menopause, post- vs pre-NR0.73 (0.54-0.98)NRAnxiety, case vs normalNRNR1.82 (1.13-2.92)Anxiety, borderline vs normalNRNR1.84 (1.17-2.91)Hot flashes, vs no1.25 (0.92-1.69)1.20 (0.87-1.65)1.64 (1.10-2.43)Corrected AUC0.73 (0.70-0.76)0.69 (0.65-0.72)0.68 (0.63-0.72)OR= Odds Ratio, CI= Confidence Interval, NR= Not Retained; *Adjusted by BMI, alcohol, smoke, socioeconomic, psychological, tumor and tx; **QLQ-C30

Table 2.Models of severe CRCI in the overall cohort**: biological biomarkers.T1 (N=1094)T2 (N=1091)T3 (N=870)OR* (95% CI)OR* (95% CI)OR* (95% CI)IL6NR0.80 (0.46-1.40)1.01 (0.64-1.60)IL1RA0.66 (0.37-1.17)0.88 (0.50-1.55)NRCRP0.94 (0.60-1.48)1.44 (0.92-2.27)NRIL20.93 (0.55-1.57)1.10 (0.61-1.97)NRIL1βNR1.55 (0.71-3.40)NRIFNγ1.86 (0.69-5.01)0.75 (0.25-2.22)NRIL101.05 (0.34-3.27)1.27 (0.58-2.78)NRIL1A0.71 (0.15-3.33)0.80 (0.17-3.66)NRIL80.96 (0.58-1.58)NRNRTNFαNR1.35 (0.67-2.73)NRMCP-11.07 (0.64-1.78)0.83 (0.51-1.35)0.80 (0.48-1.31)Corrected AUC0.72 (0.67-0.77)0.70 (0.65-0.75)0.67 (0.62-0.72)OR= Odds Ratio, CI= Confidence Interval, NR= Not Retained; *Adjusted by BMI, alcohol, smoke, socioeconomic, psychological, tumor and tx; ** Clinical predictors from previous models were forced in the models at each time-point

Citation Format: Daniele Presti, Florence Joly, Davide Soldato, Stergios Christodoulidis, Antonin Della Noce, Julie Havas, Florine Dubuisson, Barbara Pistilli, Valerie Camara-Clayette, Fabrice André, Anne-Laure Martin, Alexandra Jacquet, Sandrine Boyault, Ivan Bièche, Charles Coutant, Paul-Henry Cournede, Stefan Michiels, Caroline Pradon, Ines Vaz-Luis, Antonio Di Meglio. Cancer-related cognitive impairment (CRCI) in early breast cancer (BC) survivors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-09.

Abstract GS1-10: Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST

Background: While studies have shown feasibility and reported preliminary evidence of utility, there is no evidence that multigene sequencing improves outcome in patients with metastatic cancer. The aim of the present study was to assess the clinical utility of multigene sequencing and DNA copy number analyses.. Methods: In SAFIR02-BREAST (NCT: 02299999) and SAFIR-PI3K (NCT: 03386162), open-label multicentric phase II randomized trials, patients were selected if they had a Her2-negative metastatic breast cancer eligible to 1st or 2nd line chemotherapy. Patients underwent a pre-treatment biopsy of metastatic disease when feasible, followed by genomic analysis by next generation sequencing and SNParray. After 6 to 8 cycles of induction chemotherapy, patients without progressive disease and presenting an actionable genomic alteration, were randomized between targeted therapies matched to genomic alterations or maintenance chemotherapy. The primary objective was to evaluate whether targeted therapies guided by genomics improves progression-free survival (PFS) as compared to maintenance chemotherapy, in a pooled analyses of SAFIR02-BREAST and SAFIR-PI3K populations. A hierarchical testing was applied. The efficacy of targeted therapies matched to genomic alterations was first tested in patients presenting an ESCAT I/II alteration (ESMO Scale of Actionability of Molecular Targets). If a p value &lt;0.1 was observed in the first step, analyses were then performed in the Intent-to-treat population. Results: Out of the 1462 patients included, 238 (16%) were subsequently randomized between maintenance chemotherapy (n=81) and targeted therapy (n=157). In 115 patients presenting an ESCAT I/II genomic alteration, the median PFS was 9.1 months (90%CI: 7.1-9.8) and 2.8 (90%CI: 2.1-4.8) in matched targeted therapy and maintenance chemotherapy arms respectively (adjusted HR for stratification factors =0.41;90%CI: 0.27-0.61, p&lt;0.001). In the overall population, there was no significant difference in the duration of PFS between the two arms (adjusted HR: 0.77 (95%CI: 0.56- 1.06, p=0.109). ESCAT classification was highly predictive for the benefit of targeted therapies matched to genomic alterations (interaction test, p= 0.004). Targeted therapies matched to genomic alterations were not effective in patients without ESCAT I/II alteration (HR: 1.15, 95%CI: 0.76-1.75). The SNP array analyses (n=926) identified 21 genes altered more frequently in metastases as compared to primary tumors (TCGA+ METABRIC). Of these, focal TERT amplifications were associated with a poor outcome. Focal CDK4 amplifications were observed after resistance to CDK4 inhibitors. Finally, high HRD was associated with longer PFS in patients with BRCA mutation treated with olaparib (HR: 0.32 [95%CI: 0.12;0.83], p=0.013).. Conclusion: SAFIR02/PI3K trials report that the clinical use of multigene sequencing must be driven by a framework of actionability, and identifies new genomic alterations associated with metastatic evolution and drug resistance or sensitivity.

Citation Format: Fabrice André, Anthony Gonçalves, Thomas Filleron, Florence Dalenc, Amélie Lusque, Mario Campone, Marie-Paule Sablin, Hervé Bonnefoi, Ivan Bieche, Ludovic Lacroix, Alicia Tran-Dien, Marta Jimenez, Alexandra Jacquet, Qing Wang, Etienne Rouleau, David Gentien, Isabelle Soubeyran, Alain Morel, Monica Arnedos, Thomas Bachelot. Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS1-10.

Abstract PD2-05: Genomic profiling of PAM50-based intrinsic subtypes in HR+/HER2- advanced breast cancer (ABC) across the MONALEESA (ML) studies

Background: In the ML program, PAM50-based intrinsic subtypes (ie, luminal A [LumA], luminal B [LumB], HER2 enriched [HER2E], and basal-like [Basal]) were found to be prognostic and predictive of ribociclib benefit in ABC (Prat et al. J Clin Oncol. 2021). While ribocliclib demonstrated benefit in all subtypes (except Basal, with a limited sample size), LumB and HER2E derived the largest benefit. However, DNA features of the intrinsic subtypes in the advanced setting remain unknown. Here, we report the results of genomic profiling of baseline circulating tumor DNA (ctDNA) by PAM50-based intrinsic subtypes across ML studies. Methods: A total of 883 of 2066 patients recruited in the ML-2, -3, and -7 phase 3 trials had both tumor intrinsic subtype and plasma ctDNA next-generation sequencing (NGS)-based data obtained at baseline (ie, before starting treatment). The NGS-based panel targeted exonic regions in approximately 550 genes sequenced on an Illumina HiSeq instrument. A total of 130 patients had the normal-like subtype and were excluded from further analyses. For genes altered in &gt; 5% of patients, we assessed the differences in frequency across intrinsic subtypes. Genetic alterations included mutations, indels, and copy number alterations. For each gene, a Fisher exact test was used to test for differences in frequency across the subtypes. A false discovery rate (FDR) correction was used to adjust for multiple testing. For genes with FDR &lt; 0.10, a logistic regression model was used to quantify the relationship between subtypes and alteration status. Also, we evaluated differences across subtypes for tumor mutational burden (TMB) using analysis of variance and for ctDNA fraction using a Kruskal-Wallis test. Results: Overall, gene amplifications were more frequent in the LumB, HER2E, and Basal subtypes. CCND1 (and genes FGF3/4/19 found in the same amplicon) was more frequently altered in HER2E (14.6%) and LumB (14.3%) than in the LumA (4.8%) subtype. Similarly, FGFR1 and MYC were more frequently altered in HER2E (13% and 9.8%), Basal (12.5% and 12.5%), and LumB (8.6% and 10%) than in the LumA (3.3% and 2.3%) subtype. PIK3CA alterations, including hotspot somatic mutations, were less frequent in Basal (12.5%) than in the LumB (27.6%), LumA (33.8%), and HER2E (37.4%) subtypes. In contrast, TP53 alterations were more frequent in Basal (66.7%) and HER2E (29.3%) than in the LumB (16.2%) and LumA (12.4%) subtypes. ERBB2 alterations (n = 25) were found in the LumA, LumB, and HER2E subtypes at similar frequencies (3%-4%). ESR1 did not show any significant difference across subtypes. TMB did not differ by subtype (P = .20), even when a TMB cutoff ≥ 10 was used (P = .23). Finally, ctDNA fraction differed across subtypes (P &lt; .001), being significantly higher in the LumB (P &lt; .001) and HER2E (P &lt; .001) than in the LumA subtype. Conclusions: This is the first combined report of ctDNA NGS profiling and intrinsic molecular subtype in ABC. Differences in tumor DNA profiles were observed across PAM50 subtypes, with a trend for higher copy number alterations in HER2E and LumB than in the LumA subtype. LumA and Basal subtypes were found to have the most distinct genomic features. The Basal subtype is known to be similar to triple-negative BC from a clinical and biological perspective, which may explain the limited activity of ribociclib in this subgroup, as shown previously (Prat et al. J Clin Oncol. 2021). The pronounced activity of ribociclib in HER2E and LumB subtypes, which are enriched with somatic alterations associated with endocrine therapy resistance and tend to have a worse prognosis, warrants further investigation.

Citation Format: Aleix Prat, Nadia Solovieff, Faye Su, Aditya Bardia, Patrick Neven, Gabriel N. Hortobagyi, Debu Tripathy, Stephen Chia, Dennis Slamon, Yen-Shen Lu, Tetiana Taran, Agnes Lteif, Carlos L. Arteaga, Fabrice André. Genomic profiling of PAM50-based intrinsic subtypes in HR+/HER2- advanced breast cancer (ABC) across the MONALEESA (ML) studies [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD2-05.

Abstract P1-18-16: First line aromatase inhibitor (AI) + palbociclib with randomized switch to fulvestrant + palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Global safety results of PADA-1, a UCBG-GINECO phase III trial

Background: Aromatase inhibitors (AI) in combination with a CDK 4/6 inhibitor have been established as the standard first line treatment of non AI-resistant hormone receptor-positive (HR+) HER2- metastatic breast cancer (mBC) patients (pts). ESR1 mutations are known drivers of resistance to AIs in the metastatic setting but their actionability remains unknown. The phase 3 PADA-1 trial aimed both at refining the global safety of palbociclib combined to any AI as first line treatment of HR+ HER2- mBC pts, and at evaluating the clinical benefit associated with a switch to fulvestrant-palbociclib upon detection of a rising ESR1 mutation in blood (bESR1mut). Methods: PADA-1 (NCT03079011), a multicenter, randomized, open-label, phase 3 trial, enrolled HR+ HER2- mBC pts with no prior therapy for mBC, in the absence of AI-resistance. In the first step, pts received a combination of any AI and palbociclib at standard recommended doses and underwent centralized bESR1mut screening every two months. In the second step, bESR1mut+ pts with no clinical/imaging concomitant disease progression were randomized between continuing the same therapy (standard arm) or switching to fulvestrant-palbociclib (experimental arm). The third step consisted in an optional cross-over after tumor progression for patients randomized in the standard arm. PADA-1 co-primary endpoints were global safety of the combination of palbociclib + endocrine therapy in the whole population of patients, throughout the study, with focus on hematological toxicities; and PFS in the second step. We present here the results of the global safety co-primary endpoint. Results: From 3/2017 to 01/2019, 1017 pts were accrued in 83 sites. As per 05/2021, 272 pts were still in step 1, 35 in step 2, and 8 in step 3. The overall follow-up was 33.7 months. 232 pts have deceased. 333 SAEs have been reported, including 21 grade 5, 35 grade 4, 183 grade 3, 53 grade 2, 26 grade 1 and 15 unknown grade. Among the grade 5 cases, 2 have been declared as potentially related to the underlying treatment (Death of unknown cause, pulmonary embolism). No pt died of SARS-CoV2 infection. The main hematological toxicities encountered, as well as selected non-hematological events are described in Table 1. Permanent discontinuation of the treatment due to toxicity occurred in 39 pts/1017 (3.8%). Palbociclib dose decreases occurred in 419 (41.2%) pts. Conclusion: By the number of included patients, PADA-1 is the largest prospective trial with 1st line AI and palbociclib. Data confirm the favorable safety profile of palbociclib when combined to any AI +/- switch to fulvestrant. Hematological toxicity appears limited and is mostly restricted to non-clinically significant neutropenia. Permanent discontinuation was exceptional. Detailed per-step analyses will be presented.

Table 1.Adverse events (% pts)Grade 3, N (%)Grade 4, N (%)Neutropenia628 (61.8%)83 (8.2%)Febrile neutropenia4 (0.4%)0Thrombocytopenia18 (1.8%)3 (0.3%)Anemia24 (2.4%)0Lymphocytopenia58 (5.7%)5 (0.5%)Insterstitial lung disease4 (0.4%)0Liver enzymes increase (AST/ALT)5 (0.5%)0Mucositis10 (1%)0

Citation Format: Suzette Delaloge, Anne-Claire Hardy-Bessard, Thomas Bachelot, Jean-Yves Pierga, Jean-Luc Canon, Florian Clatot, Fabrice André, Thibault De La Motte Rouge, Barbara Pistilli, Florence Dalenc, Nadine Dohollou, Olivier Arsene, Thierry Petit, Cecilia Riedl, François Morvan, Adina Marti, Emma Lachaier, Mihaela Achille, Michel Gozy, Anne Escande, Dominique Mille, Fanny Trouboul, Sandrine Marques, Jerome Lemonnier, Frederique Berger, François-Clément Bidard. First line aromatase inhibitor (AI) + palbociclib with randomized switch to fulvestrant + palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Global safety results of PADA-1, a UCBG-GINECO phase III trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-16.

Uptake of Recommendations for Posttreatment Cancer-Related Fatigue Among Breast Cancer Survivors

BACKGROUND

Physical activity (PA) and psychosocial interventions are recommended management strategies for cancer-related fatigue (CRF). Randomized trials support the use of mind-body techniques, whereas no data show benefit for homeopathy or naturopathy.

METHODS

We used data from CANTO (ClinicalTrials.gov identifier: NCT01993498), a multicenter, prospective study of stage I-III breast cancer (BC). CRF, evaluated after primary treatment completion using the EORTC QLQ-C30 (global CRF) and QLQ-FA12 (physical, emotional, and cognitive dimensions), served as the independent variable (severe [score of ≥40/100] vs nonsevere). Outcomes of interest were adherence to PA recommendations (≥10 metabolic equivalent of task [MET] h/week [GPAQ-16]) and participation in consultations with a psychologist, psychiatrist, acupuncturist, or other complementary and alternative medicine (CAM) practitioner (homeopath and/or naturopath) after CRF assessment. Multivariable logistic regression examined associations between CRF and outcomes, adjusting for sociodemographic, psychologic, tumor, and treatment characteristics.

RESULTS

Among 7,902 women diagnosed from 2012 through 2017, 36.4% reported severe global CRF, and 35.8%, 22.6%, and 14.1% reported severe physical, emotional, and cognitive CRF, respectively. Patients reporting severe global CRF were less likely to adhere to PA recommendations (60.4% vs 66.7%; adjusted odds ratio [aOR], 0.82; 95% CI, 0.71-0.94; P=.004), and slightly more likely to see a psychologist (13.8% vs 7.5%; aOR, 1.29; 95% CI, 1.05-1.58; P=.014), psychiatrist (10.4% vs 5.0%; aOR, 1.39; 95% CI, 1.10-1.76; P=.0064), acupuncturist (9.8% vs 6.5%; aOR, 1.46; 95% CI, 1.17-1.82; P=.0008), or CAM practitioner (12.5% vs 8.2%; aOR, 1.49; 95% CI, 1.23-1.82; P<.0001). There were differences in recommendation uptake by CRF dimension, including that severe physical CRF was associated with lower adherence to PA (aOR, 0.74; 95% CI, 0.63-0.86; P=.0001) and severe emotional CRF was associated with higher likelihood of psychologic consultations (aOR, 1.37; 95% CI, 1.06-1.79; P=.017).

CONCLUSIONS

Uptake of recommendations to improve CRF, including adequate PA and use of psychosocial services, seemed suboptimal among patients with early-stage BC, whereas there was a nonnegligible interest in homeopathy and naturopathy. Findings of this large study indicate the need to implement recommendations for managing CRF in clinical practice.

Development and Validation of a Predictive Model of Severe Fatigue After Breast Cancer Diagnosis: Toward a Personalized Framework in Survivorship Care

PURPOSE

Fatigue is common and troublesome among breast cancer survivors; however, limited tools exist to predict its risk.

PATIENTS AND METHODS

Participants with stage I-III breast cancer were prospectively included from CANTO (ClinicalTrials.gov identifier: NCT01993498), collecting longitudinal data at diagnosis (before the initiation of any cancer treatment) and 1 (T1), 2 (T2), and 4 (T3) years after diagnosis. The main outcome was severe global fatigue at T2 (score ≥ 40/100, European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-C30). Analyses at T3 were exploratory. Secondary outcomes included physical, emotional, and cognitive fatigue (EORTC Quality of Life Questionnaire-FA12). Multivariable logistic regression models retained associations with severe fatigue by bootstrapped Augmented Backward Elimination. Validation methods included 10-fold internal cross-validation, overoptimism-corrected area under the receiver operating characteristic curves, and external validation.

RESULTS

Among 5,640, 5,000, and 3,400 patients at T1, T2, and T3, respectively, the prevalence of post-treatment severe global fatigue was 35.6%, 34.0%, and 31.5% in the development cohort. Retained risk factors for severe global fatigue at T2 were severe pretreatment fatigue (adjusted odds ratio v no 3.191 [95% CI, 2.704 to 3.767]); younger age (for 1-year decrement 1.015 [1.009 to 1.022]), higher body mass index (for unit increment 1.025 [1.012 to 1.038]), current smoking behavior (v never 1.552 [1.291 to 1.866]), worse anxiety (v noncase 1.265 [1.073 to 1.492]), insomnia (for unit increment 1.005 [1.003 to 1.007]), and pain at diagnosis (for unit increment 1.014 [1.010 to 1.017]), with an area under the receiver operating characteristic curve of 0.73 (95% CI, 0.72 to 0.75). Receipt of hormonal therapy was a risk factor for severe fatigue at T3 (v no 1.448 [1.165 to 1.799]). Dimension-specific risk factors included body mass index for physical fatigue and emotional distress for emotional and cognitive fatigue.

CONCLUSION

We propose a predictive model to assess fatigue among breast cancer survivors, within a personalized survivorship care framework. This may help clinicians to provide early management interventions or to correct modifiable risk factors and offer more tailored monitoring and education to patients at risk of severe post-treatment fatigue.

Identifying the Steps Required to Effectively Implement Next-Generation Sequencing in Oncology at a National Level in Europe

Next-generation sequencing (NGS) may enable more focused and highly personalized cancer treatment, with the National Comprehensive Cancer Network and European Society for Medical Oncology guidelines now recommending NGS for daily clinical practice for several tumor types. However, NGS implementation, and therefore patient access, varies across Europe; a multi-stakeholder collaboration is needed to establish the conditions required to improve this discrepancy. In that regard, we set up European Alliance for Personalised Medicine (EAPM)-led expert panels during the first half of 2021, including key stakeholders from across 10 European countries covering medical, economic, patient, industry, and governmental expertise. We describe the outcomes of these panels in order to define and explore the necessary conditions for NGS implementation into routine clinical care to enable patient access, identify specific challenges in achieving them, and make short- and long-term recommendations. The main challenges identified relate to the demand for NGS tests (governance, clinical standardization, and awareness and education) and supply of tests (equitable reimbursement, infrastructure for conducting and validating tests, and testing access driven by evidence generation). Recommendations made to resolve each of these challenges should aid multi-stakeholder collaboration between national and European initiatives, to complement, support, and mutually reinforce efforts to improve patient care.

Seroconversion rate after vaccination against COVID-19 in cancer patients-a systematic review

Background

Coronavirus disease 2019 (COVID-19) has affected >210 million people worldwide. An optimal therapeutic approach for COVID-19 remains uncertain, to date. Since the history of cancer was linked to higher mortality rates due to COVID-19, the establishment of a safe and effective vaccine coverage is crucial in these patients. However, patients with cancer (PsC) were mostly excluded from vaccine candidates' clinical trials. This systematic review aims to investigate the current available evidence about the immunogenicity of COVID-19 vaccines in PsC.

Patients and methods

All prospective studies that evaluated the safety and efficacy of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were included, with immunogenicity after the first and the second dose as the primary endpoint, when available.

Results

Vaccination against COVID-19 for PsC seems overall safe and immunogenic after well-conducted vaccination schedules. Yet the seroconversion rate remains lower, lagged or both compared to the general population. Patients with hematologic malignancies, especially those receiving B-cell-depleting agents in the past 12 months, are the most at risk of poor seroconversion.

Conclusion

A tailored approach to vaccination may be proposed to PsC, especially on the basis of the type of malignancy and of the specific oncologic treatments received.

A phase II randomised study of preoperative trastuzumab alone or combined with everolimus in patients with early HER2-positive breast cancer and predictive biomarkers (RADHER trial)

INTRODUCTION

Resistance to trastuzumab in breast cancer is an ongoing challenge. Clinical and biological effects of co-targeting HER2 and mammalian target of rapamycin (mTOR) in patients with HER2-positive early operable breast cancer via the addition of everolimus to preoperative trastuzumab were evaluated in a phase II randomised study.

METHODS

Patients were randomised 1:1 to receive trastuzumab (4 mg/kg initial dose then 2 mg/kg weekly for 5 weeks) alone or combined with everolimus (10 mg/day for 6 weeks) and then underwent surgery. Tumours were assessed by clinical examination and echography at the baseline and on treatment. The primary end-point was the clinical response rate at 6 weeks. Pathological response and safety were also evaluated. Baseline and surgery tumour samples were assessed by immunohistochemistry and multiplex immunoanalysis for predictive downstream effectors of the PI3K/AKT/mTOR and MAP kinase (MAPK) pathways.

RESULTS

Eighty-two patients were enrolled, 41 per arm. The clinical response rates were 34.1% and 43.9% with trastuzumab alone and combined with everolimus, respectively. Pathological response rates were 43.6% and 47.5%, respectively. Addition of everolimus increased toxicity, notably mucositis (82.5% versus 5.0%) and rash (57.5% versus 10.0%), but grade III/IV events were rare. No correlation between response to treatments and baseline candidate biomarkers was identified, except for PIK3CA mutations which were found to predict trastuzumab resistance. Significant changes were seen in several MAPK pathway effectors after combination therapy.

CONCLUSIONS

The addition of everolimus did not improve the efficacy, but induced MAPK signalling. Combination therapy to overcome pathway cross-talk should be considered to maximise the effectiveness of trastuzumab in this setting. ClinicalTrial.gov Identifier NCT00674414.

PI3K inhibitors are finally coming of age

Overactive phosphoinositide 3-kinase (PI3K) in cancer and immune dysregulation has spurred extensive efforts to develop therapeutic PI3K inhibitors. Although progress has been hampered by issues such as poor drug tolerance and drug resistance, several PI3K inhibitors have now received regulatory approval - the PI3Kα isoform-selective inhibitor alpelisib for the treatment of breast cancer and inhibitors mainly aimed at the leukocyte-enriched PI3Kδ in B cell malignancies. In addition to targeting cancer cell-intrinsic PI3K activity, emerging evidence highlights the potential of PI3K inhibitors in cancer immunotherapy. This Review summarizes key discoveries that aid the clinical translation of PI3Kα and PI3Kδ inhibitors, highlighting lessons learnt and future opportunities.

Intestinal microbiota influences clinical outcome and side effects of early breast cancer treatment

The prognosis of early breast cancer (BC) relies on cell autonomous and immune parameters. The impact of the intestinal microbiome on clinical outcome has not yet been evaluated. Shotgun metagenomics was used to determine the composition of the fecal microbiota in 121 specimens from 76 early BC patients, 45 of whom were paired before and after chemotherapy. These patients were enrolled in the CANTO prospective study designed to record the side effects associated with the clinical management of BC. We analyzed associations between baseline or post-chemotherapy fecal microbiota and plasma metabolomics with BC prognosis, as well as with therapy-induced side effects. We examined the clinical relevance of these findings in immunocompetent mice colonized with BC patient microbiota that were subsequently challenged with histo-compatible mouse BC and chemotherapy. We conclude that specific gut commensals that are overabundant in BC patients compared with healthy individuals negatively impact BC prognosis, are modulated by chemotherapy, and may influence weight gain and neurological side effects of BC therapies. These findings obtained in adjuvant and neoadjuvant settings warrant prospective validation.

Plasma proteomics identifies leukemia inhibitory factor (LIF) as a novel predictive biomarker of immune-checkpoint blockade resistance

BACKGROUND

Immune checkpoint blockers (ICBs) are now widely used in oncology. Most patients, however, do not derive benefit from these agents. Therefore, there is a crucial need to identify novel and reliable biomarkers of resistance to such treatments in order to prescribe potentially toxic and costly treatments only to patients with expected therapeutic benefits. In the wake of genomics, the study of proteins is now emerging as the new frontier for understanding real-time human biology.

PATIENTS AND METHODS

We analyzed the proteome of plasma samples, collected before treatment onset, from two independent prospective cohorts of cancer patients treated with ICB (discovery cohort n = 95, validation cohort n = 292). We then investigated the correlation between protein plasma levels, clinical benefit rate, progression-free survival and overall survival by Cox proportional hazards models.

RESULTS

By using an unbiased proteomics approach, we show that, in both discovery and validation cohorts, elevated baseline serum level of leukemia inhibitory factor (LIF) is associated with a poor clinical outcome in cancer patients treated with ICB, independently of other prognostic factors. We also demonstrated that the circulating level of LIF is inversely correlated with the presence of tertiary lymphoid structures in the tumor microenvironment.

CONCLUSION

This novel clinical dataset brings strong evidence for the role of LIF as a potential suppressor of antitumor immunity and suggests that targeting LIF or its pathway may represent a promising approach to improve efficacy of cancer immunotherapy in combination with ICB.

Abstract 358: A prospective study of prostate cancer metastases identifies an androgen receptor activity-low, stemness program associated with resistance to androgen receptor axis inhibitors and unveils mechanisms of clonal evolution

Background: The androgen receptor axis inhibitors (ARi) (e.g, enzalutamide, abiraterone acetate) are administered in daily practice for men with metastatic castration-resistant prostate cancer (mCRPC). However, not all patients respond, and mechanisms of both primary and acquired resistance remain largely unknown.

Methods: In a prospective trial MATCH-R (NCT02517892), 55 mCRPC patients underwent whole exome sequencing (WES) (n=45) and RNA-sequencing (RNA-seq) (n=52) of metastatic biopsies before starting ARi. Also, 16 mCRPC patients underwent biopsy at time of resistance (WES=14, RNA-seq = 14). The objectives were to identify genomic alterations associated with resistance to ARi as well as to describe clonal evolution. Primary resistance was determined at 4 months of treatment using composite criteria for progression that included serum prostate specific antigen measurements, bone scan, CT imaging and symptom assessments. Acquired resistance was defined by occurrence of progressive disease after initial response or stable disease. Associations of genomic and transcriptomic alterations with primary resistance were determined using Wilcoxon and Fisher's exact tests.

Results: At 4 months, 22/55 patients in the cohort had disease progression (primary resistance). No genomic alterations from WES analysis were significantly associated with primary resistance. Analysis of sequential biopsies suggests that mCRPC follows mainly a parallel evolution model and involve DNA-repair related mutational processes. At time of acquired resistance to ARi, most tumors acquired new drivers affecting AR pathway (e.g, AR, NCOR1/2) or lineage switching (e.g, RB1, PTEN, TP53). Using computational methods, we measured AR transcriptional function and performed gene set enrichment analysis to identify pathways whose activity state correlated with resistance. AR gene alterations and AR expression were similar between responding and non-responding patients. Transcriptional analysis demonstrated that multiple specific gene sets — including those linked to low AR transcriptional activity, stemness program, RB loss and homologous repair deficiency — were activated in both primary and acquired resistance.

Conclusion: Resistance to AR axis inhibitors results from multiple transcriptional programs already activated in pre-treatment samples. Clonal evolution analysis along with RNA-seq data indicate the role of genomic instability and lineage switching in driving acquired resistance

Citation Format: Naoual Menssouri, Loic Poiraudeau, Carole Helissey, Ludovic Bigot, Jonathan Sabio, Tony Ibrahim, Claudio Nicotra, Maud Ngocamus, Lambros Tselikas, Thierry De Baere, Etienne Rouleau, Ludovic Lacroix, Anne Chaucherau, Luc Friboulet, Ronan Flippot, Giulia Baciarello, Laurence Albiges, Emeline Colomba, Pernelle Lavaud, Stefan Michiels, Aline Maillard, Antoine Italiano, Fabrice Barlesi, Jean-Charles Soria, Jean-Yves Scoazec, christophe Massard, Benjamin Besse, Fabrice André, Karim Fizazi, Daniel Gautheret, Yohann Loriot. A prospective study of prostate cancer metastases identifies an androgen receptor activity-low, stemness program associated with resistance to androgen receptor axis inhibitors and unveils mechanisms of clonal evolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 358.

Primary results from IMpassion131, a double-blind, placebo-controlled, randomised phase III trial of first-line paclitaxel with or without atezolizumab for unresectable locally advanced/metastatic triple-negative breast cancer

BACKGROUND

In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-bound-paclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumab-paclitaxel in aTNBC.

PATIENTS AND METHODS

Eligible patients [no prior systemic therapy or ≥12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m² (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression ≥1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint.

RESULTS

Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P = 0.20; median PFS 6.0 months with atezolizumab-paclitaxel versus 5.7 months with placebo-paclitaxel]. In the PD-L1-positive population, atezolizumab-paclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placebo-paclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumab-paclitaxel versus 28.3 months with placebo-paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug.

CONCLUSION

Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. CLINICALTRIALS.GOV: NCT03125902.

Abstract 3016: Identification of the mechanisms of resistance to targeted therapies in advanced solid cancers

Despite progress in understanding aberrations that contribute to the development and progression of cancer, resistance to classical chemotherapeutic agents or novel targeted drugs continues to be a major problem in cancer therapy. Hence, the identification of the mechanisms underlying drug resistance acquisition is the key to explore new and efficient therapeutic pathways for patients. The MATCH-R clinical trial enrolls patients with oncogene-driven cancer who have had previous clinical response to targeted therapy and subsequently experienced disease progression under treatment. In the framework of this project, Gustave Roussy and XenTech are joining forces to develop a panel of patient-derived xenografts (PDXs) derived from biopsies collected from these patients at the stage of acquired resistance. These PDX models are being fully characterized at both molecular and pharmacological levels and used to improve knowledge on the mechanisms underlying resistance to treatment and to evaluate response to new treatments. In this perspective, the development of 75 PDX-AR (Acquired Resistance) models is planned over 3 years. To favor successful xenograft establishment, the first passages are performed without drug treatment, then all the models are maintained under the same therapeutic pressure the parental tumor was submitted to at the time of biopsy. When applying therapeutic pressure, we observed different types of response: resistance from the first passage under treatment, stabilization under treatment at the first passages and rapidly acquired resistance over passages, or sensitivity to treatment whereas the patient tumor showed progression under the same treatment. These different behaviors can be observed in PDX models developed from multiple metastases of a same patient and may reflect different mechanisms of resistance. Most interestingly, PDX models obtained from different metastatic lesions of a same patient can recapitulate the different behavior observed in this patient. This behavior is translated by either tumor progression in one PDX model and/or stabilization under treatment in another. These paired models greatly facilitate the identification of relevant mechanisms of drug resistance.We have now completed the development of a panel of 25 PDX models of various indications and exposed to a variety of last generation targeted therapies. We will discuss relevant examples of results that can be generated from this panel, with particular focus on the molecular features of models with acquired or intrinsic resistance to treatment and of paired models with different drug sensitivity. These data highlight the unique potential of the MATCH-R preclinical platform to identify resistance mechanisms and develop next generation therapeutic strategies.

Citation Format: Olivier Deas, Emilie Dassé, Laura Brulle-Soumare, Katell Mevel, Ludovic Bigot, Yohann Loriot, Fabrice André, Jean-Charles Soria, Benjamin Besse, Enora Le Ven, Stefano Cairo, Luc Friboulet, Jean-Gabriel Judde. Identification of the mechanisms of resistance to targeted therapies in advanced solid cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3016.

Patient-Reported Outcomes in Patients With PIK3CA-Mutated Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer From SOLAR-1

PURPOSE

In the phase III SOLAR-1 trial (NCT02437318), the PI3Kα-selective inhibitor and degrader alpelisib significantly improved median progression-free survival when added to fulvestrant in patients with phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-mutated, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. We assessed health-related quality of life using patient-reported outcome measures in these patients.

MATERIALS AND METHODS

In the PIK3CA-mutant cohort, 341 patients were randomly assigned 1:1 to receive alpelisib 300 mg daily or placebo plus fulvestrant 500 mg on days 1 and 15 of cycle 1 and on day 1 of subsequent 28-day cycles. Patient-reported outcomes were evaluated with the European Organisation for Research and Treatment of Cancer QoL of Cancer Patients and Brief Pain Inventory-Short Form questionnaires. Changes from baseline and time to 10% deterioration were analyzed using repeated measurement models and Cox models, respectively.

RESULTS

Global Health Status/QoL and functional status were maintained from baseline (mean changes < 10 points) in the alpelisib (overall change from baseline [95% CI], -3.50 [-8.02 to 1.02]) and placebo arms (overall change from baseline [95% CI], 0.27 [-4.48 to 5.02]). Overall treatment effect in Global Health Status/QoL was not significantly different between arms (-3.77; 95% CI, -8.35 to 0.80; P = .101). Time to 10% deterioration for Global Health Status/QoL was similar between arms (hazard ratio, 1.03; 95% CI, 0.72 to 1.48). Compared with placebo, deterioration in social functioning and in diarrhea, appetite loss, nausea or vomiting, and fatigue symptom subscales occurred with alpelisib. Numerical improvement in Worst Pain was observed with alpelisib versus placebo (42% v 32%, week 24; P = .090).

CONCLUSION

In SOLAR-1, there was no statistical difference in deterioration of Global Health Status/QoL between arms, whereas symptom subscales favored placebo for diarrhea, appetite loss, nausea or vomiting, and fatigue, known side effects of alpelisib. Treatment decisions must consider efficacy and tolerability; taken with clinical efficacy, these results support the benefit-risk profile of alpelisib in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative PIK3CA-mutated advanced breast cancer.