Results of the ECHO (Eating habits CHanges in Oncologic patients) Survey: An Italian Cross-Sectional Multicentric Study to Explore Dietary Changes and Dietary Supplement Use, in Breast Cancer Survivors

The role of a healthy diet in cancer prevention is well recognized. Recent data indicate that following the same advices can also improve cancer survivors’ quality of life. Breast cancer (BC) patients are commonly concerned about diet and nutrition and frequently express the need to obtain health-related information and the will to change their diet and lifestyle. Hence, be aware of survivors’ dietary changes and information needs is crucial for healthcare professionals to guide them toward optimal lifestyle choices. In order to investigate eating habits changes in a BC survivors’ population, we conceived the cross-sectional multicentric study ECHO (Eating habits CHanges in Oncologic patients) Survey. Data were collected from 684 patients, diagnosed with invasive breast cancer, in order to investigate their changes in food consumption, use of supplements, or the beginning of a specific diet, after BC diagnosis. We also examined the sources of information used and if any modification in their diets was reported to the oncologist. We primarily observed that patients increased their consumption of vegetables, pulses, nuts, fruits, wholemeal bread/pasta, grains and fish; while decreasing red and processed meat, refined bread/pasta, baked good and animal fat consumption. Survivors also reported the use of dietary supplements, mainly vitamins, aimed at counteracting therapies’ side effects. Changes in nutritional habits were often adopted without asking or informing the oncologist. Despite BC survivors made some positive changes in their nutritional habits, those modifications were mostly pursued by less than half of them, while the majority of patients consumed nutritional supplements after diagnosis. These results, as well as the failure to communicate with the physicians, reinforce the need to both improve the patient-healthcare professional relationship and to develop tailored nutrition counselling and intervention programs for cancer survivors.

Safety of assisted reproductive techniques in young women harboring germline pathogenic variants in BRCA1/2 with a pregnancy after prior history of breast cancer

BACKGROUND

Knowledge is growing on the safety of assisted reproductive techniques (ART) in cancer survivors. No data exist, however, for the specific population of breast cancer patients harboring germline BRCA1/2 pathogenic variants.

PATIENTS AND METHODS

This is a multicenter retrospective cohort study across 30 centers worldwide including women diagnosed at ≤40 years with stage I-III breast cancer, between January 2000 and December 2012, harboring known germline BRCA1/2 pathogenic variants. Patients included in this analysis had a post-treatment pregnancy either achieved through use of ART (ART group) or naturally (non-ART group). ART procedures included ovulation induction, ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection, and embryo transfer under hormonal replacement therapy.

RESULTS

Among the 1424 patients registered in the study, 168 were eligible for inclusion in the present analysis, of whom 22 were in the ART group and 146 in the non-ART group. Survivors in the ART group conceived at an older age compared with those in the non-ART group (median age: 39.7 versus 35.4 years, respectively). Women in the ART group experienced more delivery complications compared with those in the non-ART group (22.1% versus 4.1%, respectively). No other apparent differences in obstetrical outcomes were observed between cohorts. The median follow-up from pregnancy was 3.4 years (range: 0.8-8.6 years) in the ART group and 5.0 years (range: 0.8-17.6 years) in the non-ART group. Two patients (9.1%) in the ART group experienced a disease-free survival event (specifically, a locoregional recurrence) compared with 40 patients (27.4%) in the non-ART group. In the ART group, no patients deceased compared with 10 patients (6.9%) in the non-ART group.

CONCLUSION

This study provides encouraging safety data on the use of ART in breast cancer survivors harboring germline pathogenic variants in BRCA1/2, when natural conception fails or when they opt for ART in order to carry out preimplantation genetic testing.

Prognostic factors in phyllodes tumours of the breast: retrospective study on 166 consecutive cases

BACKGROUND

Phyllodes tumours (PTs) are rare fibroepithelial tumours accounting for <1% of all breast tumours. We assessed clinicopathological features and their prognostic effect in a single-institution patients' cohort.

METHODS

Patients diagnosed with PT between 2001 and 2018 at our institution were identified. Clinical, surgical and pathological features were collected. Phyllodes-related relapse was defined as locoregional or distant recurrence (contralateral excluded), whichever first.

RESULTS

A total of 166 patients were included: 115 with benign, 30 with borderline and 21 with malignant PTs. Features associated with malignant PT were younger age, larger T size, higher mitotic count, marked cytological atypia, stromal overgrowth, stromal hypercellularity, necrosis and heterologous differentiation (all p<0.01). The majority of patients with malignant PT underwent mastectomy (63.2% vs 3% of benign/borderline, p<0.001) and had negative surgical margins (83.3%). 4-year cumulative phyllodes-related relapse incidence was 7% for benign/borderline PT and 21.3% for malignant PT (p=0.107). In the entire cohort, marked cellular atypia and heterologous differentiation were associated with worse phyllodes-related relapse-free survival (HR 14.10, p=0.036 for marked vs mild atypia; HR 4.21, p=0.031 for heterologous differentiation present vs absent). For patients with benign PT, larger tumour size was associated with worse phyllodes-related relapse-free survival (HR 9.67, p=0.013 for T>5 cm vs T≤2 cm). Higher tumour-infiltrating lymphocytes (TILs) were associated with borderline and malignant PT (p=0.023); TILs were not associated with phyllodes-related relapse-free survival (HR 0.58, p=0.361 for TILs>2% vs≤2%). Overall, four patients died because of PT: three patients with malignant and one with borderline PT.

CONCLUSIONS

Patients with malignant PT had increased rates of phyllodes-related relapse and phyllodes-related death. Cellular atypia and heterologous differentiation were poor prognostic factors in the entire cohort; large tumour size was associated with an increased risk of phyllodes-related relapse in benign PT.

Impact of estrogen receptor levels on outcome in non-metastatic triple negative breast cancer patients treated with neoadjuvant/adjuvant chemotherapy

Although 1% is the recommended cut-off to define estrogen receptor (ER) positivity, a 10% cut-off is often used in clinical practice for therapeutic purposes. We here evaluate clinical outcomes according to ER levels in a monoinstitutional cohort of non-metastatic triple-negative breast cancer (BC) patients undergoing (neo)adjuvant chemotherapy. Clinicopathological data of 406 patients with ER < 10% HER2-negative BC treated with (neo)adjuvant chemotherapy between 01/2000 and 04/2019 were collected. Patients were categorized in ER-negative (ER < 1%; N = 364) and ER-low positive (1-9%, N = 42). At a median follow-up of 54 months, 88 patients had relapsed and 64 died. No significant difference was observed in invasive relapse-free survival (iRFS) and overall survival (OS) according to ER expression levels, both at univariate and multivariate analysis (5-years iRFS 74.0% versus 73.1% for ER-negative and ER-low positive BC, respectively, p = 0.6; 5-years OS 82.3% versus 76.7% for ER-negative and ER-low positive BC, respectively, p = 0.8). Among the 165 patients that received neoadjuvant chemotherapy, pathological complete response rate was similar in the two cohorts (38% in ER-negative, 44% in ER-low positive, p = 0.498). In conclusion, primary BC with ER1-9% shows similar clinical behavior to ER 1% BC. Our results suggest the use of a 10% cut-off, rather than <1%, to define triple-negative BC.

Epidemiology and clinical course of SARS-CoV-2 infection in cancer patients in the Veneto Oncology Network during the first and second pandemic waves

6511

Background: Since the beginning of the COVID-19 outbreak, the Veneto Oncology Network ROV licensed dedicated guidelines for cancer patients care during the pandemic, and developed a regional registry (ROVID) aimed at describing epidemiology and clinical course of SARS-CoV-2 infection in cancer patients. Preliminary data on 170 patients mainly diagnosed during the first pandemic wave have been published (Guarneri V, Eur J Cancer 2021). Here we report the data of additional 270 patients, comparing clinical data and outcomes between first (W1) and second (W2) pandemic waves. Methods: All patients with cancer diagnosis and documented SARS-CoV-2 infection are eligible. Data on diagnosis, comorbidities, anticancer treatments, details on SARS-CoV-infection including source of contagion, clinical presentation, hospitalization, treatments and fate of the infection are recorded. Results: 440 patients have been enrolled, 196 diagnosed during W1 (until September 2020) and 244 during W2. The most common cancer type was breast cancer (n = 116). Significant differences in clinical characteristics between W1 and W2 were the followings: ECOG PS 0 (34% vs 58%), presence of cardiac comorbidities (30% vs 13%), presence of any co-morbidities (81% vs 62%), smoking habits (23% vs 13%). Patients diagnosed in W1 were less likely on active anticancer therapy (54% vs 73%) at the time of SARS-CoV-2 infection. Distribution per stage, presence of lung metastases, disease setting (curative vs palliative), active treatment discontinuation due to infection were similar between W1 and W2. Patients diagnosed in W1 were more likely symptomatic for SARS-CoV-2 infection (80% vs 67%), and reported more frequently an in-hospital contact as potential source of infection (44% vs 9%). Significantly more patients diagnosed in W1 were hospitalized (76% vs 25%). All-cause mortality rates were 30.6% for patients diagnosed in W1 vs 12% for patients diagnosed in W2 (p < 0.001). However, deaths due to SARS-CoV-2 infection were more frequent in patients diagnosed in W2 (86% vs 54%, odds ratio 3.22; 95% CI 1.97-5.279). Conclusions: Differences in clinical characteristics between W1 and W2 reflect different pattern of virus circulation. The dramatic reduction of in-hospital contact as a source of infection reflects the efforts put in place to protect this vulnerable population from in-hospital exposure. The lower all-cause mortality rate observed in W2 is in line with the observed less frail population. However, the higher relative risk of death due to SARS-CoV-2 infection observed in W2 reinforces the need to adopt protective measures including vaccination in cancer patients, irrespectively of age, stage, and comorbidities.

Profiling of immune checkpoint biomarkers by multiplex immunofluorescence in breast cancer brain metastases

2021

Background: Despite potential clinical implications, the complexity of immune microenvironment in breast cancer (BC) brain metastases (BM) is still poorly understood. Multiplex immunofluorescence (mIF) allows simultaneous visualization of several IF labeled proteins while maintaining spatial information. This novel technique can be used to comprehensively describe BCBM immune microenvironment, potentially providing useful information to guide novel therapeutic approaches. Methods: Clinical data and archival BM samples from 60 BC patients undergoing neurosurgery (2003-2018) at three institutions were collected. BCBMs were characterized using a custom mIF panel, including immune checkpoint and co-inhibitory molecules (CD3, PD1, PD-L1, TIM3, LAG3, CD163) and localization (keratin for tumor recognition) markers. Mean marker density was determined by digital image analysis (positive cells/mm2) and classified in tumor and stroma areas. Associations between immune marker densities, BC subtype and overall survival from BM diagnosis (OS) were studied. Results: Sixty BCBM samples were analyzed; 32% HR+/HER2-, 38% HER2+, 30% HR-/HER2-. At a median follow-up of 43 months, the only clinical variable associated with OS was BC subtype (shortest for HR-/HER2- and longest for HER2+, p=0.02). In the total sample area and tumor area, no significant difference in marker density was observed according to BC subtype. In the stroma area, a significant difference in TIM3+ cell density was observed according to BC subtype (highest density in HR+/HER2- and lowest density in HER2+ tumors, Kruskal-Wallis p=0.017). Higher CD163 density (a marker of M2 macrophage polarization), both in the tumor and in the stroma area, was significantly associated with worse OS, even after correction by BC subtype. In the subgroup of patients with HR+/HER2- BCBM, high TIM3+ cell density in the stroma area was significantly associated with longer OS (median OS 54.1 versus 23 months respectively for TIM3+ density above and below median value; p=0.01). Conclusions: In BCBM, stromal TIM3+ immune infiltrate differs according to BC subtype. M2 macrophage polarization is consistently associated with worse OS across all BC subtypes and might represent a potential therapeutic target for these patients.[Table: see text]

Neoadjuvant approach as a platform for treatment personalization: focus on HER2-positive and triple-negative breast cancer

The neoadjuvant setting provides unquestionable clinical benefits for high-risk breast cancer (BC) patients, mainly in terms of expansion of locoregional treatment options and prognostic stratification. Additionally, it is also emerging as a strategical tool in the research field. In the present review, by focusing on HER2-positive and triple-negative subtypes, we examined the role of the neoadjuvant setting as a research platform to facilitate and rationalize the placement of escalation strategies, promote the adoption of biomarker-driven approaches for the investigation of de-escalated treatments, and foster the conduction of comprehensive translational analyses, thus ultimately aiming at pursuing treatment personalization. The solid prognostic role of pathologic complete response after neoadjuvant therapy, and its use as a surrogate endpoint to accelerate the drug approval process were discussed. In this context, available data on escalated treatment strategies capable of enhancing pathologic complete response (pCR) rate or improving prognosis of patients with residual disease (RD) after neoadjuvant treatment, were comprehensively reviewed. We also summarized evidence regarding the possibility of obtaining pCR with de-escalated strategies, with particular emphasis on the role of biomarker-driven approaches for patient selection. Pitfalls of the dichotomy of pCR/RD were also deepened, and data on alternative/complementary biomarkers with a possible clinical relevance in this regard were reviewed.

Immune Checkpoint Blockade in HER2-Positive Breast Cancer: What Role in Early Disease Setting?

Simple Summary

This work aims to discuss how an anti- or pro-tumor immune response could be manipulated through immune checkpoint blockade in patients with early stage HER2-positive breast cancer. By summarizing previously published evidence in the field, authors present their personal view on how immune checkpoint blockade could be implemented in the neoadjuvant setting in this patient population. The hypothesis being presented is that an appropriate and effective administration of immune checkpoint blockade could assure a lasting control of the disease, by preventing relapses. One of the research priorities should be the identification of the patients who could benefit more by this strategy.

Abstract

The present commentary synthesizes the current evidence on the role of the immune response in HER2-positive breast cancer. It points out the strengths and weaknesses of the findings observed so far, particularly in the early setting, including the clinical significance of scoring tumor-infiltrating lymphocytes. A figure proposing research hypotheses for the implementation of immune checkpoint blockade use for patient candidates to neoadjuvant treatment is presented.

ESR1 Gene Mutation in Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer Patients: Concordance Between Tumor Tissue and Circulating Tumor DNA Analysis

Endocrine therapy represents the cornerstone of treatment in hormone receptor-positive (HR+), HER2-negative metastatic breast cancer (mBC). The natural course of this disease is marked by endocrine resistance, mainly due to Estrogen Receptor 1 (ESR1) acquired mutations. The aim of this study is to evaluate the concordance between ESR1 status in metastatic tumor specimens and matched circulating tumor DNA (ctDNA). Forty-three patients with HR+, HER2-negative mBC underwent both a metastatic tumor biopsy and a liquid biopsy at the time of disease progression. DNA extracted from formalin fixed paraffin embedded (FFPE) tumor specimens and ctDNA from matched plasma were analyzed by droplet digital (dd)PCR for the main ESR1 mutations (Y537S, Y537C, Y537N, D538G, E380Q). We observed a total mutation rate of 21%. We found six mutations on tissue biopsy: Y537S (1), D538G (2), Y537N (1), E380Q (2). Three patients with no mutations in tumor tissue had mutations detected in ctDNA. The total concordance rate between ESR1 status on tumor tissue and plasma was 91%. Our results confirm the potential role of liquid biopsy as a non-invasive alternative to tissue biopsy for ESR1 mutation assessment in mBC patients.

Postsurgical Pyoderma Gangrenosum in a Breast Cancer Patient: A Case Report and Literature Review

Pyoderma gangrenosum is a rare skin necrotizing disease that can arise on a site of surgical trauma. Its pathogenesis has recently been related to dysregulation of the immune system, with inflammatory bowel disease representing the most commonly underlying systemic conditions. Several authors have also reported an association with solid malignancies (especially gastrointestinal and breast cancer). We describe the case of a 39-year-old patient diagnosed with a locally advanced, triple-negative breast cancer who developed a pyoderma gangrenosum on the surgical wound after a CVC implant with systemic complications. As the diagnosis and management of postsurgical pyoderma gangrenosum can be challenging for clinicians, underlying conditions as autoimmune disease and solid tumors have to be considered in order to guide treatment.

Abstract PD10-06: Clinical behavior and outcomes of BRCA-mutated breast cancer in young patients according to type of BRCA mutation and hormone receptor status: Results from an international cohort study

Background: Young breast cancer patients (pts) carrying a germline BRCA mutation (mBRCA) have similar outcomes as non-carriers. However, there is currently lack of evidence regarding the impact of mBRCA type and hormone receptor status on clinical behavior and outcomes of mBRCA breast cancer. We aim to address these questions in the largest dataset to date of young mBRCA breast cancer pts.

Methods: This was an international, multicenter, hospital-based, retrospective cohort study. Women harboring deleterious germline mBRCA1 or mBRCA2 that received a diagnosis of stage I-III invasive early breast cancer at age ≤40 years between January 2000 and December 2012 were included. Baseline pts, tumor, and treatment characteristics, pattern and risk over time of disease-free survival (DFS) events, and survival outcomes (DFS, distant recurrence-free interval [DRFI] and overall survival [OS]) were compared between mBRCA1 and mBRCA2 pts overall and by hormone receptor status. Multivariate Cox proportional hazard models were used to compare hazard rates (HRs).

Results: 1,236 young mBRCA breast cancer pts were included. Among 808 and 428 pts with mBRCA1 or mBRCA2, respectively, 191 (23.6%) and 356 (83.2%) had hormone receptor-positive tumors while 617 (76.4%) and 72 (16.8%) hormone receptor-negative disease (p&lt;0.001). Compared to mBRCA2 breast cancer pts, those with mBRCA1 were younger, more likely to have reported Jewish ancestry, had more grade 3 tumors, less nodal involvement, lobular histology and HER2 positivity, and received more frequently chemotherapy (all p&lt;0.001). More mBRCA1 pts with hormone receptor-positive tumors did not receive adjuvant endocrine therapy (14.7% vs. 4.2%, p&lt;0.001). No difference between mBRCA1 and mBRCA2 pts was observed in risk-reducing mastectomy (43.9% vs. 46.0%; p=0.371) or salpingo-oophorectomy (48.3% vs. 48.8%; p=1.0). Median follow-up was 7.9 years (range 5.6-10.6 years). Second primary breast cancers (17.0% vs. 12.2%, p=0.025) and non-breast primary malignancies (4.3% vs. 1.9%, p=0.033) were more frequent among mBRCA1 pts compared to mBRCA2 pts, while distant recurrences were less frequent (10.4% vs. 15.4%, p=0.013). 8-year DFS was 62.8% and 65.9% for mBRCA1 and mBRCA2 pts, respectively (adjusted HR 0.76; 95% CI 0.60-0.96). The worse DFS in mBRCA1 was observed regardless of hormone receptor status (pinteraction=0.848): hormone receptor-positive (adjusted HR 0.77; 95% CI 0.58-1.03) and hormone receptor-negative (adjusted HR 0.73; 95% CI 0.48-1.13). No differences in DRFI and OS were observed between mBRCA1 and mBRCA2 pts. Compared to pts with hormone receptor-negative disease, those with hormone receptor-positive breast cancer had higher chances of developing distant (± loco-regional) recurrences (16.1% vs. 9.0%; p&lt;0.001) and less frequent second primary malignancies (BC: 12.1% vs. 17.9%, p=0.005; non-BC: 2.8% vs. 4.0%, p=0.216). No differences in DFS and OS were observed between pts with hormone receptor-positive or negative breast cancer. However, there was a trend towards worse DRFI in women with hormone receptor-positive breast cancer as compared to those with hormone receptor-negative disease (8-year DRFI: 83.4% vs. 90.1%; adjusted HR 1.39; 95% CI 0.94-2.05).

Conclusions: In this large unique dataset, young mBRCA1 breast cancer pts had worse DFS than those with mBRCA2 mostly due to higher rates of second primary malignancies. Hormone receptor positivity had no positive prognostic value in young mBRCA breast cancer pts with a trend towards worse DRFI in those with hormone receptor-negative disease. These results provide important information for counseling young mBRCA breast cancer pts regarding treatment, prevention and follow-up care strategies.

Citation Format: Matteo Lambertini, Marcello Ceppi, Anne-Sophie Hamy, Olivier Caron, Philip D. Poorvu, Estela Carrasco, Albert Grinshpun, Kevin Punie, Christine Rousset-Jablonski, Alberta Ferrari, Shani Paluch-Shimon, Angela Toss, Claire Senechal, Fabio Puglisi, Katarzyna Pogoda, Jose Alejandro Pérez-Fidalgo, Laura De Marchis, Riccardo Ponzone, Luca Livraghi, Maria Del Pilar Estevez-Diz, Cynthia Villarreal-Garza, Maria Vittoria Dieci, Florian Clatot, Francois P. Duhoux, Rossella Graffeo, Luis Teixeira, Octavi Córdoba, Amir Sonnenblick, Arlindo R. Ferreira, Ann H. Partridge, Antonio Di Meglio, Claire Saule, Fedro A. Peccatori, Marco Bruzzone, Lucia Del Mastro, Lieveke Ameye, Judith Balmaña, Hatem A. Azim, Jr. Clinical behavior and outcomes of BRCA-mutated breast cancer in young patients according to type of BRCA mutation and hormone receptor status: Results from an international cohort study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD10-06.

Abstract PS10-02: A good prognosis of endocrine-dependent tumors among residual invasive cancer after anti-HER2 therapy: CALGB 40601 (Alliance) and validation studies

Background: Patients with HER2+ breast cancer who have residual disease after neoadjuvant anti-HER2 plus chemotherapy have a high risk of recurrence and benefit from adjuvant trastuzumab emtansine (T-DM1). We hypothesize that endocrine-responsive residual tumors after neoadjuvant treatments may have good outcomes among patients receiving only adjuvant endocrine therapy plus trastuzumab. Using paired pre- and post-treatment samples from CALGB 40601 and other neoadjuvant cohorts that did not include adjuvant T-DM1, we investigated survival by pretreatment and residual disease ESR1 and PgR gene expression in CALGB 40601, and by estrogen receptor (ER) and progesterone receptor (PR) immunohistochemistry (IHC) in the other cohorts. We considered endocrine-responsive tumors those with ER and/or PR expression by gene expression or IHC.

Methods: CALGB 40601 is a randomized neoadjuvant trial of single vs. dual HER2-targeting (trastuzumab and/or lapatinib added to paclitaxel). We only included those patients who had not suffered from disease progression or death during their preoperative treatments. In total, 77 patients with paired pretreatment and residual disease tumors were profiled by mRNA sequencing and studied. Cutoffs for ESR1 and PgR mRNA expression mimicking clinical positivity were obtained using 265 pretreatment CALGB 40601 tumors (and 1,045 TCGA samples for ESR1). We also examined ER and PR IHC in paired tumors from 202 patients treated at 4 different collaborating institutions; all had residual disease after neoadjuvant HER2 targeting plus chemotherapy. We considered ER- or PR-positive as ≥10% positively staining cells. The primary endpoint was EFS, defined as the time from randomization to event in CALGB 40601 and from the first systemic therapy to event in the 4-institution validation cohort.

Results: In 77 patients from CALGB 40601 with paired (pretreatment/residual disease) specimens, 38 (49.3%) had ESR1+/ESR1+ tumors. The EFS was superior in the ESR1+/ESR1+ (n=38) group than in the remaining others (the log-rank test, p=0.011). The 5- and 7-year EFS rates for the ESR1+/ESR1+ (n=38) were 92.1% and 89.2%, whereas the rates were uniformly &lt; 70% in the others. In particular, the 5-year EFS rate among 11 patients with ESR1+/ESR1- tumors was 61.4%. This remained significant in multivariable analysis with clinical stage and treatment arm; the hazard ratio (HR) for EFS in ESR1+/ESR1+ versus all others was 0.29 (95% CI, 0.09-0.90). In ESR1+/ESR1+ tumors, 5-year EFS rates were high for those whose residual disease and also being PgR+ (n=32) or PAM50 LumA or Normal-like (n=34) (93.8% and 97.1%, respectively). In the institutional validation cohort, pretreatment /residual disease ER(+)/ER(+) tumors (n=113) had superior 3-year EFS versus all others (p=0.010). At a median follow-up of 35.9 months, the 3-year EFS rates for ER(+)/ER(+) and all other groups were 96.6% and 82.6%, respectively. This remained strongly significant in multivariable analysis with clinical stage; the HR for EFS in ER(+)/ER(+) versus all other groups was 0.28 (95% CI, 0.09-0.88). Among 46 who also had PR+ in the residual disease, the 3-year EFS was 100.0%.

Conclusions: HER2+ patients with ER+ pretreatment and ER+ residual disease after neoadjuvant chemotherapy + HER2-targeting have a very good survival outcome despite not receiving additional anti-HER2 targeting with T-DM1. This may provide a simple mechanism to better tailor therapy within residual disease patients using serial ER measurements.

Citation Format: Sung Gwe Ahn, Aranzazu Fernandez-Martinez, Mei-Yin C. Polley, Soong June Bae, Seho Park, Núria Chic, Fara Brasó-Maristany, Benedetta Conte, Valentina Guarneri, Maria Vittoria Dieci, Gaia Griguolo, PierFranco Conte, Joon Jeong, Aleix Prat, Lisa A. Carey, Charles M Perou. A good prognosis of endocrine-dependent tumors among residual invasive cancer after anti-HER2 therapy: CALGB 40601 (Alliance) and validation studies [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-02.

Abstract PS12-22: Maintenance therapy with everolimus plus aromatase inhibitors vs aromatase inhibitors as after first-line chemotherapy in HR+/HER2- metastatic breast cancer: Updated analyses of the phase III randomized MAIN-A trial

Background Despite endocrine therapy is the mainstay of treatment for HR+/HER2- metastatic breast cancer (MBC), patients with high disease burden or those at risk of visceral crisis are still offered first-line chemotherapy (CT). Chemotherapy is generally followed by maintenance hormonal therapy. The MAIN-A study is an investigator-driven, randomized phase III trial designed to compare maintenance everolimus (EVE) combined with aromatase inhibitors (AI) versus AI alone in pts with disease control after first-line CT.Methods Postmenopausal pts achieving disease control (stable disease, partial response or complete response) after first-line CT were randomly assigned to EVE 10 mg po daily plus AI or to AI alone. Primary aim was PFS in the ITT. We present here overall survival (OS) results and the impact of tumor characteristics on PFS.Results 110 pts were randomized to EVE+AI (n=52) or to AI (n= 58). Primary aim results have been already presented (Guarneri V, ESMO Breast 2019), showing a non-significant prolongation of median PFS in the ITT population for EVE+AI (9.9 mos vs 7.2 mos, HR 0.764, 95% CI 0.501-1.164. Patients with visceral metastases tended to experience shorter PFS as compared with patients with patients with bone/soft tissues metastases (median 11.1 mos vs 6.4 mos, p=0.0746). The levels of estrogen receptor expression (&gt;or&lt; 50%) did not impact PFS, overall and by treatment arm. At the time of this writing, a total of 61 death events have been recorded. No difference in OS was observed between the two arms (median 33.9 mos for EVE+AI vs 33.5 mos for AI, HR 0.97, 95% CI 0.59-1.61).Conclusions Maintenance EVE+AI did not significantly impact on the outcome of metastatic breast cancer patients deemed suitable for first line chemotherapy.

Citation Format: Valentina Guarneri, Saverio Cinieri, Maria Vittoria Dieci, Carmelo Bengala, Gabriella Mariani, Giancarlo Bisagni, Antonio Frassoldati, Claudio Zamagni, Laura Orlando, Carlo Alberto Giorgi, Gian Luca De Salvo, PierFranco Conte. Maintenance therapy with everolimus plus aromatase inhibitors vs aromatase inhibitors as after first-line chemotherapy in HR+/HER2- metastatic breast cancer: Updated analyses of the phase III randomized MAIN-A trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-22.

Clinical behavior and outcomes of breast cancer in young women with germline BRCA pathogenic variants

Young breast cancer (BC) patients carrying a germline BRCA pathogenic variant (mBRCA) have similar outcomes as non-carriers. However, the impact of the type of gene (BRCA1 vs. BRCA2) and hormone receptor status (positive [HR+] vs. negative [HR-]) on clinical behavior and outcomes of mBRCA BC remains largely unknown. This is an international, multicenter, hospital-based, retrospective cohort study that included mBRCA patients diagnosed, between January 2000 and December 2012, with stage I-III invasive early BC at age ≤40 years. From 30 centers worldwide, 1236 young mBRCA BC patients were included. Among 808 and 428 patients with mBRCA1 or mBRCA2, 191 (23.6%) and 356 (83.2%) had HR+tumors, respectively (P < 0.001). Median follow-up was 7.9 years. Second primary BC (P = 0.009) and non-BC malignancies (P = 0.02) were more frequent among mBRCA1 patients while distant recurrences were less frequent (P = 0.02). Irrespective of hormone receptor status, mBRCA1 patients had worse disease-free survival (DFS; adjusted HR = 0.76, 95% CI = 0.60-0.96), with no difference in distant recurrence-free interval (DRFI) and overall survival (OS). Patients with HR+ disease had more frequent distant recurrences (P < 0.001) and less frequent second primary malignancies (BC: P = 0.005; non-BC: P = 0.18). No differences in DFS and OS were observed according to hormone receptor status, with a tendency for worse DRFI (adjusted HR = 1.39, 95% CI = 0.94-2.05) in patients with HR+ BC. Type of mBRCA gene and hormone receptor status strongly impact BC clinical behavior and outcomes in mBRCA young patients. These results provide important information for patients' counseling on treatment, prevention, and surveillance strategies.

Epidemiology and clinical course of severe acute respiratory syndrome coronavirus 2 infection in cancer patients in the Veneto Oncology Network: The Rete Oncologica Veneta covID19 study

Introduction

Coronavirus disease 2019 (COVID-19) pandemic started in Italy with clusters identified in Northern Italy. The Veneto Oncology Network (Rete Oncologica Veneta) licenced dedicated guidelines to ensure proper care minimising the risk of infection in patients with cancer. Rete Oncologica Veneta covID19 (ROVID) is a regional registry aimed at describing epidemiology and clinical course of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with cancer.

Materials and methods

Patients with cancer diagnosis and documented SARS-CoV-2 infection are eligible. Data on cancer diagnosis, comorbidities, anticancer treatments, as well as details on SARS-CoV-2 infection (hospitalisation, treatments, fate of the infection), have been recorded. Logistic regression analysis was applied to calculate the association between clinical/laboratory variables and death from any cause.

Results

One hundred seventy patients have been enrolled. The median age at time of the SARS-CoV infection was 70 years (25–92). The most common cancer type was breast cancer (n = 40). The majority of the patients had stage IV disease. Half of the patients had two or more comorbidities. The majority of the patients (78%) presented with COVID-19 symptoms. More than 77% of the patients were hospitalized and 6% were admitted to intensive care units. Overall, 104 patients have documented resolution of the infection. Fifty-seven patients (33%) have died. In 29 cases (17%), the cause of death was directly correlated to SARS-CoV-2 infection. Factors significantly correlated with the risk of death were the following: Eastern Cooperative Oncology Group performance status (PS), age, presence of two or more comorbidities, presence of dyspnoea, COVID-19 phenotype ≥ 3, hospitalisation, intensive care unit admission, neutrophil/lymphocyte ratio and thrombocytopenia.

Conclusions

The mortality rate reported in this confirms the frailty of this population. These data reinforce the need to protect patients with cancer from SARS-CoV-2 infection.

Immune Infiltrates in Breast Cancer: Recent Updates and Clinical Implications

In recent decades, the increasing interest in the field of immunotherapy has fostered an intense investigation of the breast cancer (BC) immune microenvironment. In this context, tumor-infiltrating lymphocytes (TILs) have emerged as a clinically relevant and highly reproducible biomarker capable of affecting BC prognosis and response to treatment. Indeed, the evaluation of TILs on primary tumors proved to be strongly prognostic in triple-negative (TN) BC patients treated with either adjuvant or neoadjuvant chemotherapy, as well as in early TNBC patients not receiving any systemic treatment, thus gaining level-1b evidence in this setting. In addition, a strong relationship between TILs and pathologic complete response after neoadjuvant chemotherapy has been reported in all BC subtypes and the prognostic role of higher TILs in early HER2-positive breast cancer patients has also been demonstrated. The interest in BC immune infiltrates has been further fueled by the introduction of the first immune checkpoint inhibitors in the treatment armamentarium of advanced TNBC in patients with PD-L1-positive status by FDA-approved assays. However, despite these advances, a biomarker capable of reliably and exhaustively predicting immunotherapy benefit in BC is still lacking, highlighting the imperative need to further deepen this issue. Finally, more comprehensive evaluation of immune infiltrates integrating both the quantity and quality of tumor-infiltrating immune cells and incorporation of TILs in composite scores encompassing other clinically or biologically relevant biomarkers, as well as the adoption of software-based and/or machine learning platforms for a more comprehensive characterization of BC immune infiltrates, are emerging as promising strategies potentially capable of optimizing patient selection and stratification in the research field. In the present review, we summarize available evidence and recent updates on immune infiltrates in BC, focusing on current clinical applications, potential clinical implications and major unresolved issues.

An overview of immune checkpoint inhibitors in breast cancer

Although breast cancer is not traditionally considered an immunogenic type of tumor, the combination of immunotherapy and chemotherapy has recently emerged as a novel treatment option in triple-negative subtype in the advanced setting and other similar combinations of immune checkpoint inhibitors with chemotherapy are expected to become part of the neoadjuvant management in the near future. In addition, encouraging results have been observed with the combination of immune checkpoint blockade with diverse biological agents, including anti-HER2 agents, CDK 4/6 inhibitors, PARP-inhibitors. The present review summarized the available evidence coming from clinical trials on the role of immune checkpoint inhibitors in the management of breast cancer, both in advanced and early setting.

Synchronous and Metachronous Breast and Ovarian Cancer: Experience From Two Large Cancer Center

Purpose

We aimed to evaluate the clinico-pathological characteristics and survival outcomes of patients with synchronous or metachronous breast cancer (BC) and ovarian cancer (OC).

Materials and Methods

Patients with synchronous or metachronous BC and OC were retrospectively identified at two large cancer centers. Clinico-pathological characteristics, BRCA1/2 status and follow-up data were gathered. Patients were classified according to the first cancer diagnosis in the following groups: Breast Cancer first, Ovarian Cancer first, Synchronous Breast and Ovarian Cancer. Overall survival (OS) was calculated as the time interval between each cancer diagnosis to death or last follow-up.

Results

Overall, 270 patients were included: n = 194 (72%) in BC first group, n = 51 (19%) in OC first, and n = 25 (9%) in synchronous. BRCA status was available for 182 (67.4%) patients and 112 (62%) harbored pathogenetic mutations. BC first group included more frequently patients with BRCA mutation, triple negative BC phenotype and more aggressive OC features. Median time between the two diagnosis was longer in BC first group vs OC first group (95 vs 68 months, p = 0.021). A total of 105 OS events occurred, mostly related to OC (70.5%). We observed no differences in terms of OS according to the first cancer diagnosis. Age >50 years and advanced OC stage were negative independent prognostic factors for OS from the first diagnosis.

Conclusions

In this cohort of patients with BC and OC, survival was dominated by OC related mortality. These data may be useful to plan and carry out adequate and timely surveillance programs and preventive measures.

PIK3CA Mutation in the ShortHER Randomized Adjuvant Trial for Patients with Early HER2+ Breast Cancer: Association with Prognosis and Integration with PAM50 Subtype

PURPOSE

We explored the prognostic effect of PIK3CA mutation in HER2⁺ patients enrolled in the ShortHER trial.

PATIENTS AND METHODS

The ShortHER trial randomized 1,253 patients with HER2⁺ breast cancer to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. PIK3CA hotspot mutations in exon 9 and 20 were analyzed by pyrosequencing. Expression of 60 genes, including PAM50 genes was measured using the nCounter platform.

RESULTS

A mutation of the PIK3CA gene was detected in 21.7% of the 803 genotyped tumors. At a median follow-up of 7.7 years, 5-year disease-free survival (DFS) rates were 90.6% for PIK3CA mutated and 86.2% for PIK3CA wild-type tumors [HR, 0.84; 95% confidence interval (CI), 0.56-1.27; P = 0.417]. PIK3CA mutation showed a favorable prognostic impact in the PAM50 HER2-enriched subtype (n = 232): 5-year DFS 91.8% versus 76.1% (log-rank P = 0.049; HR, 0.46; 95% CI, 0.21-1.02). HER2-enriched/PIK3CA mutated versus wild-type tumors showed numerically higher tumor-infiltrating lymphocytes (TIL) and significant upregulation of immune-related genes (including CD8A, CD274, PDCD1, and MYBL2, a proliferation gene involved in immune processes). High TILs as well as the upregulation of PDCD1 and MYBL2 were associated with a significant DFS improvement within the HER2-enriched subtype (HR, 0.82; 95% CI, 0.68-0.99; P = 0.039 for 10% TILs increment; HR, 0.81; 95% CI, 0.65-0.99; P = 0.049 for PDCD1 expression; HR, 0.72; 95% CI, 0.53-0.99; P = 0.042 for MYBL2 expression).

CONCLUSIONS

PIK3CA mutation showed no prognostic impact in the ShortHER trial. Within the HER2-enriched molecular subtype, patients with PIK3CA mutated tumors showed better DFS versus PIK3CA wild-type, which may be partly explained by upregulation of immune-related genes.

Abstract CT261: METAMECH -A Master Observational Trial empowering mechanobiology translational research and mechanobased proof of concept trials in breast cancer

Background: Breast cancer (BC) is the most frequent tumor in women worldwide. BC lethality is caused by aggressive, therapy-resistant metastases (mBC). Preliminary data have shown that mBC lesions are invariably embedded into a densely packed network of fibrous extracellular matrix, making the metastatic microenvironment a potent inducer of mechanical inputs, ultimately leading to the activation of the transcription factors YAP/TAZ. Aberrant mechano-signaling could thus represent a vulnerability of metastasis, which can be exploited to develop new therapeutic strategies. To investigate how metastatic outgrowth is regulated by the physical properties of the microenvironment, and how the altered mechano-transduction of human BC metastasis can be exploited to define new unconventional therapies, we designed and activated METAMECH, a Master Observational Trial (MOT). MOTs are trial constructs hybridizing a canonical observational trial with a multiplex sample-collection platform, aimed to empower the bi-directional collaboration between pre-clinical and clinical research, an essential prerequisite to feed and implement precision oncology. Methods: METAMECH (IFOM-CPO007/2019/PO006) is a MOT that will follow a stage-mixed cohort of at least 500 BC patients throughout their course of treatments, until death or a minimum of 5 years. METAMECH has been designed to streamline the study of the co-evolutionary landscape between tumor and host cells across all BC subtypes. METAMECH is a resource for integrative clinical and imaging data and fresh and archival sample collection which will allow to auction mechanotransduction mechanisms supporting the outgrowth of human metastases, mine for new potentially actionable targets and permit the selection of appropriate patients for mechano-biology experimentally-driven trials. METAMECH is a multi-tiers research scaffold that will allow to integrate the clinical and basic aspects of the project, to optimize patients enrollment and the logistic of longitudinal collection of theirs data/samples. A customized data lake is being designed for data storage, analysis and retrieval. To facilitate patients access, METAMECH has been designed as a flexible infrastructure organized in TIERS, which allow to pursue different objectives: TIER0/1, Retrieving/Recording: to retrospectively and prospectively access to selected cohorts of clinically annotated BC samples to validate/discover mechanotransduction-linked biomarkers and create a mechano-classifier; TIER2, Modelling: to develop pertinent experimental models to study the aberrant mechanisms underlying the metastatic outgrowth and define mechanotransduction-targeting therapeutic strategies; TIER3, Linking: to access data and samples of patients enrolled in Proof-of-Concept trials to prove the efficacy and study/understand resistance mechanisms of mechanotransduction-targeting therapies.

Citation Format: Paolo Luraghi, Luca Lazzari, Maria Vittoria Dieci, Serena Bellani, Chiara Soffientini, Rosario Rizzuto, Antonio Rosato, Vincenzo Costanzo, Giorgio Scita, Giannino Del Sal, Massimiliano Pagani, Marco Foiani, Claudio Tripodo, Silvio Bicciato, Giovanni Blandino, Alberto Zambelli, Valter Torri, Matteo Fassan, PierFranco Conte, Silvia Marsoni, Stefano Piccolo. METAMECH -A Master Observational Trial empowering mechanobiology translational research and mechanobased proof of concept trials in breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT261.

De-escalated therapy for HR+/HER2+ breast cancer patients with Ki67 response after 2-week letrozole: results of the PerELISA neoadjuvant study

BACKGROUND

In human epidermal growth factor receptor 2 (HER2+) breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive versus negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-week letrozole.

PATIENTS AND METHODS

PerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-week letrozole, and then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for five cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a two-stage Simon's design, to reject the null hypothesis, at least 8/43 pCR had to be documented.

RESULTS

Sixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95% confidence interval 11.1% to 34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched than in other subtypes (45.5% versus 13.8%, P = 0.042).

CONCLUSIONS

The primary end point of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared.

EUDRACT NUMBER

2013-002662-40.

CLINICALTRIALS.GOV IDENTIFIER

NCT02411344.

Validation of Residual Proliferative Cancer Burden as a Predictor of Long-Term Outcome Following Neoadjuvant Chemotherapy in Patients with Hormone Receptor-Positive/Human Epidermal Growth Receptor 2-Negative Breast Cancer

Background

The integration of residual cancer burden (RCB) and post‐treatment Ki67 as residual proliferative cancer burden (RPCB) has been proposed as a stronger predictor of long‐term outcome in unselected patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT), as compared with RCB. However, no specific analysis in hormone‐receptor‐positive (HR+) human epidermal growth receptor 2‐negative (HER2−) BC is available so far.

Materials and Methods

A cohort of 130 patients with HR+/HER2− BC who underwent NACT between 2000 and 2014 was included. Archival surgical specimens were evaluated for RCB. RPCB was calculated by combining RCB and Ki67 as previously described. Patients were categorized in four RCB and RPCB categories (pathological complete response and tertiles). Disease‐free survival (DFS) and overall survival (OS) estimates were determined by Kaplan‐Meier analysis and compared using the log‐rank test. Overall change of χ² and c‐indexes were used to compare the performance of the prognostic models.

Results

RPCB was calculated for 85 patients. After a median follow up of 8.5 years, RCB was associated with OS (p = .048) but not with DFS (p = .152); RPCB was instead significantly associated with both DFS and OS (p = .034 and p < .001, respectively). In terms of OS, RPCB provided a significant amount of prognostic information beyond RCB (∆χ² 5.73, p < .001). In addition, c‐index for OS prediction was significantly higher for RPCB as compared with RCB (0.79 vs. 0.61, p = .03).

Conclusion

This is the first study evaluating RPCB in patients with HR+/HER2− BC treated with NACT. In this independent cohort, RPCB was a strong predictor of DFS and OS. The better performance of RPCB versus RCB was in part due to the ability of RPCB to discriminate a subgroup of patients with a particularly worse prognosis after NACT, who may be candidates for clinical trials evaluating novel adjuvant strategies.

Implications for Practice

The present work validated residual proliferative cancer burden (RPCB) as a strong predictor of long‐term outcome in patients with hormone receptor‐positive human epidermal growth receptor 2‐negative (HR+/HER2−) breast cancer (BC) treated with neoadjuvant chemotherapy. In addition, results from the present study suggest RPCB as a promising tool to identify patients with HR+/HER2− BC who might potentially benefit from the inclusion in clinical trials evaluating novel or escalated postneoadjuvant treatment strategies because it allowed to discriminate a subgroup of patients with particularly poor prognosis despite having received subsequent endocrine therapy in the adjuvant setting.

This article reports on the prognostic value of the Residual Proliferative Cancer Burden index in a cohort of patients with HR‐positive HER2‐negative breast cancer undergoing neoadjuvant chemotherapy.

Pregnancy After Breast Cancer in Patients With Germline BRCA Mutations

PURPOSE

Young women with germline BRCA mutations have unique reproductive challenges. Pregnancy after breast cancer does not increase the risk of recurrence; however, very limited data are available in patients with BRCA mutations. This study investigated the impact of pregnancy on breast cancer outcomes in patients with germline BRCA mutations.

PATIENTS AND METHODS

This is an international, multicenter, hospital-based, retrospective cohort study. Eligible patients were diagnosed between January 2000 and December 2012 with invasive early breast cancer at age ≤ 40 years and harbored deleterious germline BRCA mutations. Primary end points were pregnancy rate, and disease-free survival (DFS) between patients with and without a pregnancy after breast cancer. Pregnancy outcomes and overall survival (OS) were secondary end points. Survival analyses were adjusted for guarantee-time bias controlling for known prognostic factors.

RESULTS

Of 1,252 patients with germline BRCA mutations (BRCA1, 811 patients; BRCA2, 430 patients; BRCA1/2, 11 patients) included, 195 had at least 1 pregnancy after breast cancer (pregnancy rate at 10 years, 19%; 95% CI, 17% to 22%). Induced abortions and miscarriages occurred in 16 (8.2%) and 20 (10.3%) patients, respectively. Among the 150 patients who gave birth (76.9%; 170 babies), pregnancy complications and congenital anomalies occurred in 13 (11.6%) and 2 (1.8%) cases, respectively. Median follow-up from breast cancer diagnosis was 8.3 years. No differences in DFS (adjusted hazard ratio [HR], 0.87; 95% CI, 0.61 to 1.23; P = .41) or OS (adjusted HR, 0.88; 95% CI, 0.50 to 1.56; P = .66) were observed between the pregnancy and nonpregnancy cohorts.

CONCLUSION

Pregnancy after breast cancer in patients with germline BRCA mutations is safe without apparent worsening of maternal prognosis and is associated with favorable fetal outcomes. These results provide reassurance to patients with BRCA-mutated breast cancer interested in future fertility.

ERBB2 mRNA Expression and Response to Ado-Trastuzumab Emtansine (T-DM1) in HER2-Positive Breast Cancer

Trastuzumab emtansine (T-DM1) is approved for the treatment of human epidermal growth factor receptor 2 (HER2)-positive (HER2+) metastatic breast cancer (BC) and for residual disease after neoadjuvant therapy; however, not all patients benefit. Here, we hypothesized that the heterogeneity in the response seen in patients is partly explained by the levels of human epidermal growth factor receptor 2 gene (ERBB2) mRNA. We analyzed ERBB2 expression using a clinically applicable assay in formalin-fixed paraffin-embedded (FFPE) tumors (primary or metastatic) from a retrospective series of 77 patients with advanced HER2+ BC treated with T-DM1. The association of ERBB2 levels and response was further validated in 161 baseline tumors from the West German Study (WGS) Group ADAPT phase II trial exploring neoadjuvant T-DM1 and 9 in vitro BC cell lines. Finally, ERBB2 expression was explored in 392 BCs from an in-house dataset, 368 primary BCs from The Cancer Genome Atlas (TCGA) dataset and 10,071 tumors representing 33 cancer types from the PanCancer TCGA dataset. High ERBB2 mRNA was found associated with better response and progression-free survival in the metastatic setting and higher rates of pathological complete response in the neoadjuvant setting. ERBB2 expression also correlated with in vitro response to T-DM1. Finally, our assay identified 0.20-8.41% of tumors across 15 cancer types as ERBB2-high, including gastric and esophagus adenocarcinomas, urothelial carcinoma, cervical squamous carcinoma and pancreatic cancer. In particular, we identified high ERBB2 mRNA in a patient with HER2+ advanced gastric cancer who achieved a long-lasting partial response to T-DM1. Our study demonstrates that the heterogeneity in response to T-DM1 is partly explained by ERBB2 levels and provides a clinically applicable assay to be tested in future clinical trials of breast cancer and other cancer types.

Integration of tumour infiltrating lymphocytes, programmed cell-death ligand-1, CD8 and FOXP3 in prognostic models for triple-negative breast cancer: Analysis of 244 stage I-III patients treated with standard therapy

BACKGROUND

Tumour infiltrating lymphocytes (TILs) are an established prognostic biomarker for triple-negative breast cancer (TNBC). We evaluated the role of programmed cell-death ligand-1 (PD-L1), CD8 and FOXP3 expression in refining a prognostic model for non-metastatic TNBC beyond classic factors and TILs.

METHODS

Primary tumour samples from 244 early patients with TNBC, all treated with surgery and chemotherapy, were collected. Stromal TILs were evaluated on haematoxylin-eosin slides according to guidelines. PD-L1, CD8 and FOXP3 were assessed by immunohistochemistry and evaluated by digital pathology.

RESULTS

TILs, PD-L1, CD8 and FOXP3 were positively correlated with each other (P < 0.001). TILs were confirmed as an independent prognostic factor. When PD-L1, CD8 and FOXP3 were added to multivariable models including classic factors (age, stage, histologic grade) and TILs, PD-L1 provided the largest amount of additional prognostic information: likelihood ratio χ² 4.60, P = 0.032 (in a model including classic factors and TILs 10% increments) and likelihood ratio χ² 6.50, P = 0.011 (in a model including classic factors and TILs >30% versus <30%). In the subset of patients treated with neoadjuvant chemotherapy, FOXP3 provided further prognostic information beyond classic factors, TILs and pathological complete response (pCR) (likelihood ratio χ² 5.01, P = 0.025). For patients who did not achieve a pCR, the expression of CD8 and PD-L1 was significantly increased from baseline to residual disease.

CONCLUSIONS

Beyond clinicopathological factors and TILs, other immune biomarkers may add prognostic information for early TNBC. The increased PD-L1 expression on residual disease after neoadjuvant chemotherapy strengthens the rationale of testing immune checkpoint inhibitors in the post-neoadjuvant setting.

Biomarkers for HER2-positive metastatic breast cancer: Beyond hormone receptors

The overexpression of human epidermal growth factor receptor-2 (HER2) results in a biologically and clinically aggressive breast cancer (BC) subtype. Since the introduction of anti-HER2 targeted agents, survival rates of patients with HER2-positive metastatic BC have dramatically improved. Currently, although the treatment decision process in metastatic BC is primarily based on HER2 and hormone-receptor (HR) status, a rapidly growing body of data suggests that several other sources of biological heterogeneity may characterize HER2-positive metastatic BC. Moreover, pivotal clinical trials of new anti-HER2 antibody-drug conjugates showed encouraging results in HER2-low metastatic BC, thus leading to the possibility, in the near future, to expand the pool of patients suitable for HER2-targeted treatments. The present review summarizes and puts in perspective available evidence on biomarkers that hold the greatest promise to become potentially useful tools for optimizing HER2-positive metastatic BC patients' prognostic stratification and treatment in the next future. These biomarkers include HER2 levels and heterogeneity, HER3, intrinsic molecular subtypes by PAM50 analysis, DNA mutations, and immune-related factors. Molecular discordance between primary and metastatic tumors is also discussed.

Impact of metastases directed radiation therapy on CDK4/6 inhibitors dose reduction and treatment discontinuation for metastatic HR+/HER2- breast cancer (MBC)

562

Background: Cyclin-Dependent Kinase 4/6 inhibitors (CDK4/6i) represent the standard I-II line for hormonal receptors positive/human epidermal growth factor receptor 2 negative metastatic breast cancer (MBC) patients. Metastases directed radiotherapy (RT) for these patients is commonly used with palliative or radical schedules during systemic treatment. Although encouraging preliminary results were published, there is still a lack of robust data on the safety concerning RT during CDK4/6i treatment. Methods: we analyzed at Our Institution 85 consecutive patients treated in I (n=47) and II line (n=38) for MBC with CDK4/6i between April 2017 and September 2019 (22 ribociclib, 63 palbociclib). Overall, 25 (29.4%) patients received metastases directed RT during CDK4/6i treatment, including 14 concomitant (16.5%) and 11 sequential (12.9%). Estimated CDK4/6i half-life is 26 and 30 hours for palbociclib and ribociclib, respectively. Five half-lives are required to reduce drug concentration by 95-97%; thus, we also analyzed CDK4/6i treatment as non-concomitant or sequential to RT. Main endpoints of our analysis were impact of RT on CDK4/6i dose reduction and discontinuation, overall adverse events rate (any grade and grade ≥2), and neutropenia grade ≥2 as per CTCAE scale version 5.0. Results: at a median follow up of 12 months (range 3-29), we observed a CDK4/6i dose reduction in 35 patients (41.2%) and 5 patients (5.9%) discontinued treatment due to adverse events; 82 patients (96.5%) experienced any grade of toxicity, 72 (84.7%) a grade ≥2 and 70 patients (82.4%) neutropenia grade ≥2. We did not observe significant difference in terms of CDK4/6i dose reduction or discontinuation, any grade or grade ≥2 toxicity, neutropenia grade ≥2 in the comparison between patients receiving RT versus no RT and between patients receiving concomitant RT versus sequential RT versus no-RT (Table). Conclusions: our results showed that the prescription of a metastases directed RT during treatment with a CDK4/6i as I-II line for MBC did not significantly impact on dose reduction or discontinuation caused by an exceeding in adverse event rate. Although these promising results, caution should be used and cooperative initiatives strongly encouraged. [Table: see text]

Survival analysis of the prospective randomized Cher-Lob study evaluating the dual anti-HER2 treatment with trastuzumab and lapatinib plus chemotherapy as neoadjuvant therapy for HER2-positive breast cancer (BC)

582

Background: The CHER-LOB randomized phase II study showed that the combination of lapatinib and trastuzumab plus chemotherapy increases the pathologic complete response (pCR) rate compared with chemotherapy plus either trastuzumab or lapatinib. Here we report the results of survival analysis according to treatment arm and pCR. Methods: The CherLOB study randomized 121 HER2-positive, stage II-IIIA breast cancer patients to anthracyclines/taxane-based chemotherapy plus trastuzumab, lapatinib, or both. After surgery, patients received adjuvant trastuzumab for up to 1 year. The primary end point of the study was met, with a relative increase of 80% in the pCR rate achieved with chemotherapy plus trastuzumab and lapatinib compared with chemotherapy plus either trastuzumab or lapatinib (Guarneri, J Clin Oncol 2012). Relapse-free survival (RFS) was calculated from randomization to breast cancer recurrence (locoregional or distant) or death from any cause, whichever first. Overall survival (OS) was calculated from randomization to death from any cause. Results: At a median follow up of 8.8 years, RFS rates at 5 years were: 85.8% in the trastuzumab + lapatinib arm, 77.8% in the trastuzumab arm, 78.1% in the lapatinib arm (log-rank p = 0.160). Patients treated with dual HER2 blockade (trastuzumab + lapatinib arm) experienced numerically better RFS as compared to patients treated with single HER2 blockade (trastuzumab arm and lapatinib arm combined): 5-yr RFS 85.8% vs 78.0%, log-rank p = 0.087; HR = 0.51, 95% CI 0.23-1.12, p = 0.093. The achievement of pCR was a strong prognostic factor. 5-yr RFS rate was 97.3% for pCR patients vs 72.9% for non-pCR patients (log-rank p < 0.001, HR = 0.12, 95% CI 0.03-0.49, p = 0.003); similar significant results were observed in both the estrogen receptor-negative and estrogen-receptor positive subgroups. OS was also improved in pCR patients: 8-yr OS rates were 97.2% vs 80.0% for non pCR patients (log-rank p = 0.028, HR = 0.14, 95% CI 0.02-1.08, p = 0.060). Conclusions: In the Cher-LOB study, there was a not statistically significant signal for a better RFS for patients who received dual HER2 blockade with trastuzumab and lapatinib plus chemotherapy as compared to patients treated with single anti-HER2 agent (trastuzumab or lapatinib) plus chemotherapy. Patients achieving a pCR had longer RFS and OS as compared to non-pCR patients. Clinical trial information: NCT00429299 .

Immune microenvironment profiling of breast cancer brain metastases using multiplex immunofluorescence

2526

Background: Despite clinical implications, the complexity of brain metastases (BM) immune microenvironment in breast cancer (BC) patients is poorly understood. Multiplex immunofluorescence (mIF), a novel imaging technique allowing simultaneous visualization and quantification of several IF labeled proteins while maintaining spatial information, holds promise to comprehensively describe BCBM immune microenvironment, potentially providing valuable information to improve treatment. Methods: Clinical data and archival BM samples were collected for 60 BC patients undergoing neurosurgery (2003-2018) at three institutions. BM immune contexture was characterized using a custom mIF panel, including cell subtyping (CD4, CD8, FOXP3, CD68), activation (Granzyme B) and localization (keratin for tumor recognition) markers. Mean immune cell density (cells/mm2) for each sample was determined by digital image analysis and classified in tumor and stroma areas. Associations between immune subpopulations, BC subtype and overall survival from BM diagnosis (OS) were studied. Results: Up to date, 30 BCBM samples have been analyzed; 33% HR+/HER2-, 20% HR-/HER2+, 10% HR+/HER2+, 37% HR-/HER2-. At a median follow-up of 46 months, BC subtype was the only clinical variable associated with OS (longest for HER2+ and shortest for HR-/HER2-, log-rank p = 0.002). In the total sample area, no significant difference in immune cell densities was observed according to BC subtype. In the tumor area, HR+/HER2- tumors showed higher densities of CD8+ and CD68+ cells compared to other subtypes (p = 0.036 and p = 0.016, respectively). In stroma, HR-/HER2- tumors presented numerically higher densities of CD4+ and FOXP3+ cells and higher ratio of CD4/CD8 and FOXP3/CD8 ratio (not statistically significant). Higher CD4/CD8 and FOXP3/CD8 ratio in the stroma was significantly associated with worse OS, even after correction by BC subtype (Table). Conclusions: In BCBM, immune infiltrate differs according to BC subtype. Preliminary results suggest that a more tolerogenic immune microenvironment is associated with worse OS and might represent a target for optimization of immunotherapy for these patients. Updated results for all 60 patients will be presented. [Table: see text]

Phase III randomized study of adjuvant treatment with the ANTI-PD-L1 antibody avelumab for high-risk triple negative breast cancer patients: The A-BRAVE trial

TPS598

Background: Chemotherapy represents, today, the only treatment option for triple negative breast cancer (TNBC) and still a considerable proportion of pts with primary TNBC experience disease relapse. The risk is particularly high in the presence of poor prognostic features, such as more advanced stage and, for pts treated with neoadjuvant chemotherapy, failure to achieve a pCR. Recent evidence suggest that immunotherapy can play a major role in TNBC pts. Methods: The A-BRAVE trial is an investigator-driven trial sponsored by the University of Padova (Dept. of Surgery, Oncology and Gastroenterology). This is a phase III, multicentric, randomized adjuvant study that compares 1 year of treatment with the anti PD-L1 avelumab vs observation for pts who completed treatment with radical intent for primary TNBC including surgery and chemotherapy. The study enrolls pts in two strata: -Stratum A: primary TNBC pts who completed surgery followed by adjuvant, defined according to one of the following stage categories: if pN2, any pT; if pN1, pT > 2 cm; if pN0, pT > 5 cm. -Stratum B: primary TNBC pts who completed neoadjuvant chemotherapy followed by surgery who did not achieve pCR. Pts who also received additional adjuvant chemotherapy for no more than 6 months are eligible in Stratum B, after the completion of the adjuvant chemotherapy. Pts are randomized (1:1, balanced for strata A and B) to receive Avelumab 10 mg/kg I.V. q2w for 1 year or to observation. The first and second co-primary endpoints are disease-free survival (DFS) in all pts and DFS in Stratum B pts. With a planned sample size of n = 474 pts the trial has 90% power to detect a HR = 0.60 for the first co-primary endpoint (n = 172 events required). Taking into account that the percentage of patients enrolled in the stratum B could range from 70 to 80%, there will be 70-79% power to detect a HR = 0.60 at alpha allocated in this patient subgroup (second co-primary endpoint). Secondary objectives include: DFS in PD-L1 positive pts, overall survival, safety, biomarkers. Tumor tissue, plasma samples and fecal samples are collected for biomarker analysis. The study is currently recruiting across 73 sites in Italy and UK. As of February 2020, n = 349 pts have been enrolled. EUDRACT 2016‐000189‐45. The authors present the A-BRAVE trial in progress on behalf of Italian and UK investigators. Clinical trial information: NCT02926196 .

Olaparib for advanced breast cancer

Olaparib, an oral PARP-inhibitor, has shown clinical benefit for HER2-negative advanced breast cancer patients carrying a germinal BRCA1/2 mutation. In a randomized Phase III trial, olaparib significantly prolonged progression-free survival as compared with chemotherapy of physician choice. Moreover, in the same trial, a prespecified subgroup analysis reported an overall survival benefit for patients not previously pretreated with chemotherapy for metastatic disease. This review focuses on available preclinical, pharmacokinetic and pharmacodynamic data regarding olaparib and clinical evidence of its antitumor efficacy (both as monotherapy and in combination) and tolerability in breast cancer patients. Open questions, such as use of appropriate biomarkers for patient selection and combination/sequencing with other anticancer drugs, are also addressed.

Association of tumor-infiltrating lymphocytes with distant disease-free survival in the ShortHER randomized adjuvant trial for patients with early HER2+ breast cancer

BACKGROUND

There is the need to identify new prognostic markers to refine risk stratification for HER2-positive early breast cancer patients. The aim of this study was to evaluate the association of tumor-infiltrating lymphocytes (TILs) with distant disease-free survival (DDFS) in patients with HER2-positive early breast cancer enrolled in the ShortHER adjuvant trial which compared 9 weeks versus 1-year trastuzumab in addition to chemotherapy, and to test the interaction between TILs and treatment arm.

PATIENTS AND METHODS

Stromal TILs were assessed for 866 cases on centralized hematoxylin and eosin-stained tumor slides. The association of TILs as 10% increments with DDFS was assessed with Cox models. Kaplan-Meier curves were estimated for patients with TILs ≥20% and TILs <20%. Median follow-up was 6.1 years.

RESULTS

Median TILs was 5% (Q1-Q3 1%-15%). Increased TILs were independently associated with better DDFS in multivariable model [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.59-0.89, P = 0.006, for each 10% TILs increment]. Five years DDFS rates were 91.1% for patients with TILs <20% and 95.7% for patients with TILs ≥20% (P = 0.025). The association between 10% TILs increments and DDFS was significant for patients randomized to 9 weeks of trastuzumab (HR 0.60, 95% CI 0.41-0.88) but not for patients treated with 1 year of trastuzumab (HR 0.89, 95% CI 0.71-1.12; test for interaction P = 0.088). For patients with TILs <20%, the HR for the comparison between the short versus the long arm was 1.75 (95% CI 1.09-2.80, P=0.021); whereas, for patients with TILs ≥20% the HR for the comparison of short versus long arm was 0.23 (95% CI 0.05-1.09, P = 0.064), resulting in a significant interaction (P = 0.015).

CONCLUSIONS

TILs are an independent prognostic factor for HER2-positive early breast cancer patients treated with adjuvant chemotherapy and trastuzumab and may refine the ability to identify patients at low risk of relapse eligible for de-escalated adjuvant therapy.

Cancer care during the spread of coronavirus disease 2019 (COVID-19) in Italy: young oncologists' perspective

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Abstract P3-08-05: Impact of estrogen receptor levels on outcome in triple negative breast cancer patients treated with (neo)adjuvant chemotherapy

Background: Although 1% is recommended by guidelines as cut-off for estrogen receptor (ER) positivity, the 10% cut-off is often used in clinical practice based on studies showing that breast cancers with ER ≥1% &&lt;10% have biological characteristics and prognosis similar to those with ER &lt;1%. Our aim was to compare disease-free survival (DFS) and overall survival (OS) according to ER level in a cohort of patients with HER2-negative, ER&lt;10% and progesterone receptor &lt;10% undergoing (neo)adjuvant chemotherapy. Methods: Clinicopathological data of patients with triple negative breast cancer (defined as ER and progesterone receptor &lt;10% and HER2-negative) treated at our Institution with (neo)adjuvant chemotherapy between January 2000 and April 2019 were collected. Patients were categorized according to ER expression; &lt;1% or ≥1%&&lt;10%. Pathologic complete response (pCR) was defined as ypT0/is and ypN0. DFS was calculated from date of diagnosis to date of relapse (locoregional or distant), death or last follow up. OS was calculated from the date of diagnosis to date of death or last follow up. Hazard ratios and 95% CI were calculated with the Cox proportional hazard regression model. Results: 406 patients were included: 364 with ER&lt;1%, 42 with ER≥1%&&lt;10%. Main characteristics: median age 54 years (range 25-84), ductal histology 91% (N 367), grade 3 88% (N 350), median ki67 58%, stage at diagnosis: I 33% (N 134), II 52% (N 212), III 15% (N 59). There was no significant difference in clinicopathological characteristics according to ER level. However, ER≥1%&&lt;10% tumors had a numerically higher frequency of advanced disease stages (I 19% N=8, II 57% N=24, III 24% N=10, p=0.057).Almost half of the patients (41%, N=165) received neoadjuvant chemotherapy: 39% in the ER&lt;1% and 57% in the ER≥1%&&lt;10% cohort (p=0.032). pCR was achieved by 63 patients (38%). pCR rate was similar in the two cohorts (38% in ER&lt;1% cohort, 44% in ER≥1%&&lt;10% cohort, p=0.498). 274 patients (67%) received adjuvant chemotherapy (41 after previous neoadjuvant treatment): 69% in the ER&lt;1% and 55% in the ER≥1%&&lt;10% cohort (p=0.092). With a median follow up of 54 months, 88 patients had relapsed and 64 died. No difference in DFS and OS was observed according to ER levels: 5-year DFS was 73.7% in ER&lt;1% and 73.1% in ER≥1%&&lt;10% cohort (log-rank p=0.610); 5-year OS was 82.3% in ER&lt;1% and 76.7% in ER≥1%&&lt;10% cohort (log-rank p=0.820). Disease stage at diagnosis was the only clinicopathological variable significantly associated with DFS and OS in the overall study cohort (data not shown). DFS and OS Hazard Ratios for ER≥1%&&lt;10% tumors as compared to ER&lt;1% tumors at univariable analysis and after correction by stage are presented in the table. Conclusions: Early HER2-negative primary breast cancer with ER &lt;10% behaves clinically like ER&lt;1% breast cancer in terms of DFS and OS after (neo)adjuvant chemotherapy. Our results support the definition of TNBC as HER2-negative breast cancer with ER&lt;10% and PgR&lt;10%, rather than &lt;1%.

DFS and OS Hazard Ratios for ER≥1%&&lt;10% tumors as compared to ER&lt;1% tumorsDFSHazard Ratio (95% CI)Hazard Ratio (95% CI) corrected by stagep-valueER&lt;1%RefRef0.957ER≥1%&&lt;10%1.19 (0.61-2.30)0.98 (0.51-1.91)OSHazard Ratio (95% CI)Hazard Ratio (95% CI) corrected by stagep-valueER&lt;1%RefRef0.805ER≥1%&&lt;10%1.10 (0.50-2.40)0.90 (0.41-2.00)

Citation Format: Gaia Griguolo, Maria Vittoria Dieci, Michele Bottosso, Vassilena Tsvetkova, Carlo Alberto Giorgi, Silvia Angelini, Giulia Tasca, Enrico Cumerlato, Marcello Lo Mele, PierFranco Conte, Valentina Guarneri. Impact of estrogen receptor levels on outcome in triple negative breast cancer patients treated with (neo)adjuvant chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-05.

Abstract P5-06-14: Integrating CD8, FOXP3 and PD-L1 expression in prognostic models for triple negative breast cancer (TNBC): An analysis of 265 patients treated with standard therapy for stage I-III disease

Background: Tumor infiltrating lymphocytes (TILs) are strong prognostic biomarkers for early TNBC. We evaluated the role of CD8, FOXP3 and PD-L1 expression in refining prognostic models for non-metastatic TNBC in a large cohort of patients treated with standard therapy. Methods: Consecutive patients diagnosed with stage I-III TNBC (ER/PgR &lt;10%, HER2 0/1+ or ISH non amplified) between May 2012 and December 2015 were included. All patients received treatment with surgery, chemotherapy (neoadjuvant or adjuvant) and radiotherapy (when indicated). For each case, three FFPE tumor slides were stained for CD8 (Clone C8/144B, Dako Cytomation), FOXP3 (Clone 236A/E7, dilution 1:200, Abcam) and PD-L1 (IHC 73-10 Research Use Only assay developed by Agilent Technologies). One slide was stained for cytokeratins with MNF116. Digital slides were evaluated by a Visiopharm® software application, following alignment of the CD8, FOXP3 and PD-L1 slides with the MNF116 slide. The density of CD8 and FOXP3 expression was calculated as the number of cells/mm2 of stroma area. For PD-L1, the % of positive stromal cells over the total of stromal cells was analyzed. Disease-free survival (DFS) was calculated from diagnosis to relapse or death. The Harrell’s c-index was used to determine the cut-offs for CD8, FOXP3 and PD-L1 to be used in survival analyses. Results: 265 TNBC pts were evaluated. Median TILs was 10% (Q1-Q3 3%-25%), median CD8 was 249 (Q1-Q3 109-568), median FOXP3 was 57 (Q1-Q3 21-134), median PD-L1 was 5.2% (Q1-Q3 0.2%-25.4%). TILs, CD8, FOXP3 and PD-L1 were positively correlated with each other (p&lt;0.001): CD8 showed strong correlation with TILs (Spearman’s coefficient 0.753), FOXP3 and PD-L1 showed moderate correlation with TILs (Spearman’s coefficient 0.535 and 0.587). Higher TILs, CD8, FOXP3 and PD-L1 were associated with age ≤50yrs (p=0.002, p=0.004, p=0.065, p=0.011), Grade 3 (p=0.001, p=0.006, p=0.006, p=0.003) and Ki67 ≥30% (p=0.056, p=0.024, p=0.004, p=0.005). There was no association between immune markers and stage. Among classic clinicopathologic factors, TILs (10% increments) and stage at diagnosis were independent prognostic parameters in multivariate analysis (HR 0.81, 95% CI 0.69-0.94 p=0.005 for TILs, HR 2.01 95% ci 1.01-4.23 P=0.047 for stage II vs stage I and HR 5.31 95% CI 2.54-11.11 p&lt;0.001 for stage III vs stage I). In univariate analysis, high CD8 (≥443), high FOXP3 (≥57) and high PD-L1 (&gt;20%) were all significantly associated with improved DFS (HR 0.36 95%CI 0.18-0.72, p=0.004 for CD8; HR 0.48 95%CI 0.28-0.80, p=0.005 for FOXP3; HR 0.52 95%CI 0.28-0.97, p=0.039 for PD-L1). FOXP3 and PD-L1 provided significant additional prognostic information beyond a model containing TILs and stage: likelihood ratio χ2 5.12, p=0.024 for FOXP3; likelihood ratio χ2 5.52, p=0.019 for PD-L1. CD8 did not add relevant prognostic information beyond TILs and stage (likelihood ratio χ2 2.76, p=0.097). Including both FOXP3 and PD-L1 did not add further prognostic information to models already containing TILs, stage and either FOXP3 or PD-L1. Conclusions: FOXP3 and PD-L1 expression evaluated with a software-assisted method were prognostic for stage I-III TNBC pts treated with standard therapy and may contribute to refine the prognostic stratification beyond stage and TILs.

This study was supported by a grant from Merck KGaA.

Citation Format: Maria Vittoria Dieci, Vassilena Tsvetkova, Gaia Griguolo, Federica Miglietta, Deborah Bacchin, Giulia Tasca, Carlo Alberto Giorgi, Enrico Cumerlato, Enrico Orvieto, Valentina Guarneri, Pierfranco Conte. Integrating CD8, FOXP3 and PD-L1 expression in prognostic models for triple negative breast cancer (TNBC): An analysis of 265 patients treated with standard therapy for stage I-III disease [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-14.

HER2-Enriched Subtype and ERBB2 Expression in HER2-Positive Breast Cancer Treated with Dual HER2 Blockade

BACKGROUND

Identification of HER2-positive breast cancers with high anti-HER2 sensitivity could help de-escalate chemotherapy. Here, we tested a clinically applicable RNA-based assay that combines ERBB2 and the HER2-enriched (HER2-E) intrinsic subtype in HER2-positive disease treated with dual HER2-blockade without chemotherapy.

METHODS

A research-based PAM50 assay was applied in 422 HER2-positive tumors from five II-III clinical trials (SOLTI-PAMELA, TBCRC023, TBCRC006, PER-ELISA, EGF104090). In SOLTI-PAMELA, TBCRC023, TBCRC006, and PER-ELISA, all patients had early disease and were treated with neoadjuvant lapatinib or pertuzumab plus trastuzumab for 12-24 weeks. Primary outcome was pathological complete response (pCR). In EGF104900, 296 women with advanced disease were randomized to receive either lapatinib alone or lapatinib plus trastuzumab. Progression-free survival (PFS), overall response rate (ORR), and overall survival (OS) were evaluated.

RESULTS

A total of 305 patients with early and 117 patients with advanced HER2-positive disease were analyzed. In early disease, HER2-E represented 83.8% and 44.7% of ERBB2-high and ERBB2-low tumors, respectively. Following lapatinib and trastuzumab, the HER2-E and ERBB2 (HER2-E/ERBB2)-high group showed a higher pCR rate compared to the rest (44.5%, 95% confidence interval [CI] = 35.4% to 53.9% vs 11.6%, 95% CI = 6.9% to 18.0%; adjusted odds ratio [OR] = 6.05, 95% CI = 3.10 to 11.80, P < .001). Similar findings were observed with neoadjuvant trastuzumab and pertuzumab (pCR rate of 66.7% in HER2-E/ERBB2-high, 95% CI = 22.3% to 95.7% vs 14.7% in others, 95% CI = 4.9% to 31.1%; adjusted OR = 11.60, 95% CI = 1.66 to 81.10, P = .01). In the advanced setting, the HER2-E/ERBB2-high group was independently associated with longer PFS (hazard ratio [HR] = 0.52, 95% CI = 0.35 to 0.79, P < .001); higher ORR (16.3%, 95% CI = 8.9% to 26.2% vs 3.7%, 95% CI = 0.8% to 10.3%, P = .02); and longer OS (HR = 0.66, 95% CI = 0.44 to 0.97, P = .01).

CONCLUSIONS

Combining HER2-E subtype and ERBB2 mRNA into a single assay identifies tumors with high responsiveness to HER2-targeted therapy. This biomarker could help de-escalate chemotherapy in approximately 40% of patients with HER2-positive breast cancer.

Use of scalp cooling device to prevent alopecia for early breast cancer patients receiving chemotherapy: A prospective study

Chemotherapy-induced alopecia (CIA) affects the majority of patients receiving chemotherapy (CT) for early breast cancer. It is a highly distressing side effect of CT, with psychological and social impact. Primary aim of the present analysis was to assess the efficacy of scalp cooling with DigniCap® in preventing CIA. Success rate was defined as patients' self-reported hair loss <50% according to Dean scale. In this analysis, we reported success rate at 3 weeks after the first CT course and at 3 weeks after the last CT course. Secondary endpoints included self-reported tolerability and patients' judgment on scalp cooling performance. Consecutive early breast cancer patients admitted to Istituto Oncologico Veneto who were recommended to receive neoadjuvant or adjuvant CT, were eligible to undergo scalp cooling during the CT administration within this study. 135 patients were included: 74% received adjuvant CT and 26% neoadjuvant CT (P < .001). The type of CT was: docetaxel-cyclophosphamide (26%), paclitaxel (23%), epirubicin-cyclophosphamide followed by paclitaxel (32%), and paclitaxel followed by epirubicincyclophosphamide (19%). The rate of success in preventing alopecia was 77% (104/135) at 3 weeks from the start of CT and 60% (81/135) at 3 weeks from the end of treatment. Higher success rates were reported in non-anthracycline (71%) compared to anthracycline-containing CT regimens (54%; P < 0.001). Premature discontinuation of scalp cooling was reported in 29/135 patients (21.5%), including withdrawal for alopecia (16/29), for low scalp cooling tolerability (8/29) or both (5/29). Scalp cooling was generally well tolerated. These results overall suggest that the use of scalp cooling is effective in preventing alopecia in the majority of early breast cancer patients receiving neoadjuvant or adjuvant CT, especially for patients undergoing a taxane-based non-anthracycline regimen.

Prognostic value of tumor-infiltrating lymphocytes in patients with early-stage triple-negative breast cancers (TNBC) who did not receive adjuvant chemotherapy

BACKGROUND

Although stromal tumor-infiltrating lymphocytes (sTILs) have been considered an important prognostic factor in early-stage triple-negative breast cancer (TNBC), there have been limited data on their prognostic value in the absence of adjuvant chemotherapy.

PATIENTS AND METHODS

A pooled analysis was carried out using four cohorts of TNBC patients not treated with chemotherapy. sTILs were evaluated in the most representative tumoral block of surgical specimens. Cox proportional hazards regression models were used for invasive disease-free survival (iDFS), distant disease-free survival (D-DFS), and overall survival (OS), fitting sTILs as a continuous variable adjusted for clinicopathologic factors.

RESULTS

We analyzed individual data of 476 patients from 4 centers diagnosed between 1989 and 2015. Their median age was 64 years. The median tumor size was 1.6 cm and 83% were node-negative. The median level of sTILs was 10% (Q1-Q3, 4%-30%). Higher grade was associated with higher sTILs (P < 10-3). During follow-up, 107 deaths, and 173 and 118 events for iDFS and D-DFS were observed, respectively. In the multivariable analysis, sTILs obtained an independent prognostic value for all end points (likelihood ratio χ2 = 7.14 for iDFS; P < 10-2; χ2 = 9.63 for D-DFS, P < 10-2; χ2 = 5.96 for OS, P = 0.015). Each 10% increment in sTILs corresponded to a hazard ratio of 0.90 [95% confidence interval (CI) 0.82 - 0.97] for iDFS, 0.86 (95% CI 0.77 - 0.95) for D-DFS, and 0.88 (95% CI 0.79 - 0.98) for OS, respectively. In patients with pathological stage I tumors with sTILs ≥30% (n = 74), 5-year iDFS was 91% (95% CI 84% to 96%), D-DFS was 97% (95% CI 93% to 100%), and OS was 98% (95% CI 95% to 100%).

CONCLUSION

sTILs add important prognostic information in systemically untreated early-stage TNBC patients. Notably, sTILs can identify a subset of stage I TNBC patients with an excellent prognosis without adjuvant chemotherapy.

Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial

BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial.

METHODS

The ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death.

RESULTS

A total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n = 517) of patients to a more favorable stage category. Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P < 0.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P < 0.001). The C index was similar (0.69209 and 0.69249, P = 0.975). Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P = 0.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9 weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P = 0.080).

CONCLUSIONS

The prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment.

TRIAL REGISTRATION

EUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Programmed Cell Death Ligand 1 in Breast Cancer: Technical Aspects, Prognostic Implications, and Predictive Value

In the light of recent advances in the immunotherapy field for breast cancer (BC) treatment, especially in the triple-negative subtype, the identification of reliable biomarkers capable of improving patient selection is paramount, because only a portion of patients seem to derive benefit from this appealing treatment strategy. In this context, the role of programmed cell death ligand 1 (PD-L1) as a potential prognostic and/or predictive biomarker has been intensively explored, with controversial results. The aim of the present review is to collect available evidence on the biological relevance and clinical utility of PD-L1 expression in BC, with particular emphasis on technical aspects, prognostic implications, and predictive value of this promising biomarker. IMPLICATIONS FOR PRACTICE: In the light of the promising results coming from trials of immune checkpoint inhibitors for breast cancer treatment, the potential predictive and/or prognostic role of programmed cell death ligand 1 (PD-L1) in breast cancer has gained increasing interest. This review provides clinicians with an overview of the available clinical evidence regarding PD-L1 as a biomarker in breast cancer, focusing on both data with a possible direct impact on clinic and methodological pitfalls that need to be addressed in order to optimize PD-L1 implementation as a clinically useful tool for breast cancer management.

Prognostic and Predictive Implications of PTEN in Breast Cancer: Unfulfilled Promises but Intriguing Perspectives

The characterization of tumor biology and consequently the identification of prognostic and predictive biomarkers represent key issues for the translational research in breast cancer (BC). Phosphatase and tensin homolog deleted on chromosome ten (PTEN), the negative regulator of the proto-oncogenic phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway, constitutes one of the most intriguing tumor suppressor genes involved in a series of biological processes, such as cell growth and survival, cellular migration and genomic stability. Loss of PTEN activity, due to protein, genetic or epigenetic alterations, was reported in up to almost half of BC cases. Recently, besides the role of PTEN in the pathogenesis of BC, investigated for over 20 years after the PTEN discovery, several retrospective and prospective translational studies, in the early and advanced setting, reported controversial results regarding the association between PTEN functional status and both clinical outcome and response to various BC treatments. This review explores the pre-clinical and clinical role of PTEN in BC with regard to the potential association of PTEN with prognosis and treatment response or resistance, underlying the complexity of the interpretation of available results and suggesting potential future perspectives.

Inclusion of Platinum Agents in Neoadjuvant Chemotherapy Regimens for Triple-Negative Breast Cancer Patients: Development of GRADE (Grades of Recommendation, Assessment, Development and Evaluation) Recommendation by the Italian Association of Medical Oncology (AIOM)

In the absence of identified therapeutic targets, chemotherapy is the main systemic treatment option for triple-negative breast cancer (TNBC). The achievement of a pathological complete response (pCR) after neoadjuvant chemotherapy leads to good outcome, whereas patients not achieving a pCR are at high risk of relapse. Various trials have evaluated the inclusion of platinum in neoadjuvant chemotherapy regimens for TNBC, leading to non-univocal results. The panel of the Italian Association of Medical Oncology (AIOM) Guidelines on Breast Cancer developed a clinical recommendation on the addition of platinum to anthracycline/taxane-based neoadjuvant chemotherapy for TNBC by using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology and the Evidence to Decision framework (EtD). Five studies were eligible. The panel identified the following outcomes of benefit: pCR (critical), disease/event-free survival (DFS/EFS, critical), and overall survival (OS, critical). The panel identified febrile neutropenia (critical), serious adverse events (critical), anemia grade 3–4 (important), thrombocytopenia grade 3–4 (important) as outcomes of harms. The probability of pCR was higher in the platinum-based chemotherapy group versus control group (RR = 1.45, 95%CI 1.28–1.64); however, no impact on long-term outcome was observed. Neoadjuvant treatment regimens containing platinum resulted in a non-significant increase in the risk of febrile neutropenia and in a significant increase in the risk serious adverse events, G3–G4 anemia and G3–G4 thrombocytopenia: 11.3% versus 0.8%, RR = 15.66 (95%CI 6.38–38.44). The panel judged uncertain/favorable the benefit/harms balance. The panel’s final recommendation was conditional in favor of the inclusion of platinum in anthracycline/taxane-based neoadjuvant regimens for TNBC.

Androgen Receptor Expression and Association With Distant Disease-Free Survival in Triple Negative Breast Cancer: Analysis of 263 Patients Treated With Standard Therapy for Stage I-III Disease

Background: We evaluated immunohistochemical AR expression and correlation with prognosis in a large series of homogeneously treated patients with primary TNBC.

Material and Methods: Patients diagnosed with stage I-III TNBC between 2000 and 2015 at Istituto Oncologico Veneto who received treatment with surgery and neoadjuvant and/or adjuvant chemotherapy were included. Whole tissue slides were stained for AR. AR-positive expression was defined as >1% of positively stained tumor cells. Distant-disease-free survival (DDFS) was calculated from diagnosis to distant relapse or death. Late-DDFS was calculated from the landmark of 3 years after diagnosis until distant relapse or death.

Results: We included 263 primary TNBC patients. Mean AR expression was 14% (range 0–100%), and 29.7% (n = 78) of patients were AR+. AR+ vs. AR- cases presented more frequently older age (p < 0.001), non-ductal histology (p < 0.001), G1-G2 (p = 0.003), lower Ki67 (p < 0.001) and lower TILs (p = 0.008). At a median follow up of 81 months, 23.6% of patients experienced a DDFS event: 33.3% of AR+ and 19.5% of AR- patients (p = 0.015). 5 years DDFS rates were 67.2% and 80.6% for AR+ and AR- patients (HR = 1.82 95%CI 1.10–3.02, p = 0.020). AR maintained an independent prognostic role beyond stage, but when TILs were added to the model only stage and TILs were independent prognostic factors. AR was the only factor significantly associated with late-DDFS: 16.4% of AR+ and 3.4% of AR- patients experienced a DDFS after the landmark of 3 years after diagnosis (p = 0.001). Late-DDFS rates at 5 years from the 3-year landmark were 75.8% for AR+ and 95.2% for AR- patients (log-rank p < 0.001; HR = 5.67, 95%CI 1.90–16.94, p = 0.002).

Conclusions: AR expression is associated with worse outcome for patients with TNBC. In particular, AR+ TNBC patients are at increased risk of late DDFS events. These results reinforce the rationale of AR targeting in AR+ TNBC.

Impact of 21-Gene Breast Cancer Assay on Treatment Decision for Patients with T1-T3, N0-N1, Estrogen Receptor-Positive/Human Epidermal Growth Receptor 2-Negative Breast Cancer: Final Results of the Prospective Multicenter ROXANE Study

BACKGROUND

The ROXANE Italian prospective study evaluated the impact of the 21-gene Recurrence Score (RS) results on adjuvant treatment decision for patients with early breast cancer.

MATERIALS AND METHODS

Nine centers participated. Physicians used the RS test whenever unsure about adjuvant treatment recommendation for patients with estrogen receptor-positive/human epidermal growth receptor 2-negative, T1-T3, N0-N1 early breast cancer. Pre-RS and post-RS treatment recommendations were collected.

RESULTS

A total of 251 patients were included. N0 patients (61%) showed higher grade (p < .001) and higher Ki67 (p = .001) and were more frequently progesterone receptor negative (p = .012) as compared with N1 patients. RS results were as follows: <11, n = 63 (25.1%); 11-25, n = 143 (57%); and ≥26, n = 45 (17.9%). Higher RS was found in N0 vs. N1 patients (p = .001) and in cases of G3 (p < .001) and higher Ki67 (p < .001). The rate of change in treatment decision was 30% (n = 75), mostly from chemotherapy (CT) plus hormone therapy (CT + HT) to hormone therapy (HT; 76%, n = 57/75). The proportion of patients recommended to CT + HT was significantly reduced from pre-RS to post-RS (52% to 36%, p < .0001). CT use reduction was more evident for N1 patients (55% to 27%) than for N0 patients (50% to 42%) and was observed only in cases of RS ≤17.

CONCLUSION

Physicians predominantly used the 21-gene assay in N0 patients with a more aggressive biology or in N1 patients showing more indolent biology. In this selected patient population, the use of RS testing led to a 30% rate of change in treatment decision. In the N1 patient subgroup, the use of RS testing contributed to reduce CT use by more than half.

IMPLICATIONS FOR PRACTICE

This study shows that, even in a context in which physicians recommend a high proportion of patients to endocrine treatment alone before knowing the results of the Recurrence Score (RS) assay, the use of the RS test, whenever uncertainty regarding adjuvant treatment recommendation is present, significantly contributes in further reducing the use of chemotherapy, especially for N1 patients.

PAM50 HER2-enriched subtype as an independent prognostic factor in early-stage HER2+ breast cancer following adjuvant chemotherapy plus trastuzumab in the ShortHER trial

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Background: We investigated the prognostic role of the PAM50 HER2-enriched (HER2-E) subtype in HER2+ early breast cancer enrolled in the randomized Phase III ShortHER trial. Methods: The ShortHER study randomized 1254 HER2+ early breast cancer patients to receive 9 weeks vs 1 year of adjuvant trastuzumab combined with chemotherapy. Gene expression measured using nCounter platform was available for 438 surgical samples. Intrinsic subtyping was determined using the research-based PAM50 predictor. Metastasis-free survival (MFS) was calculated from randomization to distant disease recurrence or death (median follow up 72 months). Uni- and multi-variable analysis were performed using Cox models. Results: PAM50 subtype distribution was: HER2-E 53% (N = 233), Luminal A 20% (N = 87), Luminal B 10% (N = 43), Normal-like 11% (N = 48) and Basal-like 6% (N = 27). HER2-E subtype was associated with hormone receptor-negative status (p < 0.001) and TILs ≥20% (p < 0.001), but not with stage and age ( < or ≥60 yrs). HER2-E subtype was associated with worse MFS vs other PAM50 subtypes overall (HR 2.78, p = 0.001), in the short (HR 2.24, p = 0.046), and in the long arm (HR 4.04, p = 0.011). Multivariable Cox model confirmed the independent prognostic value of HER2-E subtype (Table). HER2-E subtype added significant prognostic value on top of clinicopathological variables (Likelihood ratio test p < 0.001). Conclusions: HER2-E intrinsic subtype is an independent prognostic factor for HER2+ early breast cancer patients treated with adjuvant chemotherapy and trastuzumab. Integration of PAM50 subtype in prognostic algorithms can help refine risk stratification. These findings warrant independent validation. Clinical trial information: NCT00629278. [Table: see text]