Breast cancer highlights from 2023: Knowledge to guide practice and future research

This narrative work highlights a selection of published work from 2023 with potential implications for breast cancer practice. We feature publications that have provided new knowledge immediately relevant to patient care or for future research. We also highlight guidelines that have reported evidence-based or consensus recommendations to support practice and evaluation in breast cancer diagnosis and treatment. The scope of selected highlights represents various domains and disciplines in cancer control, from prevention to treatment of early and advanced breast cancer.

Tumor-Infiltrating Lymphocytes (TILs) in Breast Cancer: Prognostic and Predictive Significance across Molecular Subtypes

Tumor-infiltrating lymphocytes (TILs) are pivotal in the immune response against breast cancer (BC), with their prognostic and predictive significance varying across BC subtypes. In triple-negative BC (TNBC), higher TIL levels correlate with improved prognosis and treatment response, guiding therapeutic strategies and potentially offering avenues for treatment de-escalation. In metastatic TNBC, TILs identify patients with enhanced immunotherapy response. HER2+ BC, similar to TNBC, exhibits positive correlations between TILs and treatment response, especially in neoadjuvant settings. Luminal BC generally has low TILs, with limited prognostic impact. Single hormone receptor-positive BCs show distinct TIL associations, emphasizing subtype-specific considerations. TILs in ductal carcinoma in situ (DCIS) display ambiguous prognostic significance, necessitating further investigation. Standardizing TIL assessment methods is crucial for unlocking their full potential as biomarkers, guiding treatment decisions, and enhancing patient care in BC.

Anti-HER2 Drugs for the Treatment of Advanced HER2 Positive Breast Cancer

OPINION STATEMENT

Approximately 15-20% of breast cancers (BC) demonstrate HER2 overexpression/gene amplification. Historically, before the era of HER2-directed therapies, this subtype was associated with poor prognosis. Anti-HER2 agents dramatically changed the natural course of disease and significantly prolonged patients' survival. In recent years, a number of new anti-HER2 therapies have been developed, and their approvals offer new therapeutic options for patients with advanced HER2-positive breast cancer. At present, HER2 pathway blocking drugs used in the treatment of metastatic breast cancer worldwide include trastuzumab and pertuzumab in the first-line treatment; trastuzumab deruxtecan and trastuzumab emtansine in the second line; and tucatinib, neratinib, lapatinib, and margetuximab in further lines of treatment of advanced HER2 positive breast cancer. Additionally, there are many clinical trials underway evaluating drugs blocking the HER2 pathway in advanced disease setting. This article presents new treatment options, discussing the most important findings from clinical trials and real-world reports, clinical benefits and risks of treatment, as well as efficacy of re-treatment with trastuzumab in metastatic breast cancer. New data challenge the current standards, and a number of questions arise regarding the optimal sequence of anti-HER2 targeted therapies, the optimal combination, including endocrine agents in luminal HER2 positive tumors and treatment of special patient population such as patients with brain metastases (BM).

Improved Characterization of Circulating Tumor Cells and Cancer-Associated Fibroblasts in One-Tube Assay in Breast Cancer Patients Using Imaging Flow Cytometry

Circulating tumor cells (CTCs) and circulating cancer-associated fibroblasts (cCAFs) have been individually considered strong indicators of cancer progression. However, technical limitations have prevented their simultaneous analysis in the context of CTC phenotypes different from epithelial. This study aimed to analyze CTCs and cCAFs simultaneously in the peripheral blood of 210 breast cancer patients using DAPI/pan-keratin (K)/vimentin (V)/alpha-SMA/CD29/CD45/CD31 immunofluorescent staining and novel technology-imaging flow cytometry (imFC). Single and clustered CTCs of different sizes and phenotypes (i.e., epithelial phenotype K+/V- and epithelial-mesenchymal transition (EMT)-related CTCs, such as K+/V+, K-/V+, and K-/V-) were detected in 27.6% of the samples and correlated with metastases. EMT-related CTCs interacted more frequently with normal cells and tended to occur in patients with tumors progressing during therapy, while cCAFs coincided with CTCs (mainly K+/V- and K-/V-) in seven (3.3%) patients and seemed to correlate with the presence of metastases, particularly visceral ones. This study emphasizes the advantages of imFC in the field of liquid biopsy and highlights the importance of multimarker-based analysis of different subpopulations and phenotypes of cancer progression-related cells, i.e., CTCs and cCAFs. The co-detection of CTCs and cCAFs might improve the identification of patients at higher risk of progression and their monitoring during therapy.

Designing clinical trials based on modern imaging and metastasis-directed treatments in patients with oligometastatic breast cancer: a consensus recommendation from the EORTC Imaging and Breast Cancer Groups

Breast cancer remains the most common cause of cancer death among women. Despite its considerable histological and molecular heterogeneity, those characteristics are not distinguished in most definitions of oligometastatic disease and clinical trials of oligometastatic breast cancer. After an exhaustive review of the literature covering all aspects of oligometastatic breast cancer, 35 experts from the European Organisation for Research and Treatment of Cancer Imaging and Breast Cancer Groups elaborated a Delphi questionnaire aimed at offering consensus recommendations, including oligometastatic breast cancer definition, optimal diagnostic pathways, and clinical trials required to evaluate the effect of diagnostic imaging strategies and metastasis-directed therapies. The main recommendations are the introduction of modern imaging methods in metastatic screening for an earlier diagnosis of oligometastatic breast cancer and the development of prospective trials also considering the histological and molecular complexity of breast cancer. Strategies for the randomisation of imaging methods and therapeutic approaches in different subsets of patients are also addressed.

Are All Societies Ready for Digital Tools? Feasibility Study on the Use of Mobile Application in Polish Early Breast Cancer Patients Treated with Perioperative Chemotherapy

BACKGROUND

The population of individuals affected by breast cancer is growing, and with advances in cancer treatment implemented into usual care, there is an urgent need to improve the recognition, monitoring and treatment of therapy-induced adverse effects. This study aims to explore the use of an in-app electronic questionnaire to assess and monitor chemotherapy-related symptoms in early breast cancer patients treated with perioperative chemotherapy.

METHOD

Between December 2019 and June 2021, 72 female study participants used the mobile app Centrum Chorób Piersi UCK and completed an in-app questionnaire about the 14 most common chemotherapy-related symptoms. Replies including symptoms with a critical value triggered automatic email alerts to the nursing team.

RESULTS

Acceptance of the study was higher among younger women and patients originating from rural areas, while possible digital exclusion among patients >60 years was observed during the enrolment process. A total of 55 participants completed the electronic questionnaire at least once and generated 553 responses with 1808 specific problems reported. Fatigue (n = 428) was the most common problem, and fever (n = 5) the least reported problem. A total of 21 participants triggered alerts with responses containing symptoms with critical value assessment (n = 89). Significant negative correlation was observed between the number of responses and time from the first chemotherapy administration; however, the number of responses was not determined by any sociodemographic or medical factors. Significant positive correlations were identified between the number of communicated problems and participants' age. The usage of our electronic symptom assessment questionnaire decreased substantially after the period of active encouragement during the study enrolment.

CONCLUSIONS

Not all societies are ready for innovative eHealth solutions. Patients' age should be carefully considered when app-based interventions are introduced to usual cancer care. Additional support is suggested for older patients to improve their awareness and participation in eHealth interventions. More research involving older participants is needed to explore and address their particular needs and perspectives on eHealth solutions.

Olaparib efficacy in patients with germline BRCA ‐ mutated, HER2 ‐negative metastatic breast cancer: subgroup analyses from the phase III OlympiAD trial

In the primary analysis of the phase III OlympiAD trial, olaparib significantly prolonged progression-free survival (PFS) vs chemotherapy treatment of physician's choice (TPC) in patients with germline BRCA-mutated (gBRCAm), HER2-negative metastatic breast cancer (mBC). We report subgroup analyses for the final analysis at a median OS follow-up of 18.9 months (olaparib) and 15.5 months (TPC). Patients (N = 302) with gBRCAm, HER2-negative mBC and ≤2 previous lines of chemotherapy for mBC were randomized 2:1 to open-label olaparib (300 mg twice daily) or TPC. All subgroup analyses were prespecified except site of metastases. Investigator-assessed median PFS was 8.0 months (95% confidence interval [CI] 5.8-8.4; 176/205 events) for olaparib and 3.8 months (95% CI 2.8-4.2; 83/97 events) for TPC (hazard ratio 0.51, 95% CI 0.39-0.66). In subgroup analyses, median PFS hazard ratios (95% CI) favored olaparib: hormone receptor status (triple-negative: 0.47, 0.32-0.69; hormone receptor-positive: 0.52, 0.36-0.75); gBRCAm (BRCA1: 0.49, 0.35-0.71; BRCA2: 0.49, 0.33-0.74); site of metastases (visceral/CNS: 0.53, 0.40-0.71; non-visceral: 0.45, 0.23-0.98); prior chemotherapy for mBC (yes: 0.51, 0.38-0.70; no: 0.49, 0.30-0.82); prior platinum-based chemotherapy for BC (yes: 0.49, 0.30-0.83; no: 0.50, 0.37-0.69); progressive disease at randomization (yes: 0.48, 0.35-0.65; no: 0.61, 0.36-1.07). Investigator-assessed objective response rates were higher across all subgroups with olaparib (35-68%) vs TPC (5-40%). Global health status/health-related quality of life increased in all subgroups with olaparib vs decreased/no change with TPC. These data confirm the consistency of olaparib benefit across patient subgroups in OlympiAD.

Abstract GS1-09: Abemaciclib plus endocrine therapy for HR+, HER2-, node-positive, high-risk early breast cancer: results from a pre-planned monarchE overall survival interim analysis, including 4-year efficacy outcomes

Background Adjuvant abemaciclib (a CDK4 and 6 inhibitor) combined with ET resulted in significant and clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in patients (pts) with HR+, HER2-, node-positive, high risk EBC in the monarchE trial, and is an approved adjuvant therapy for these patients. Here we present efficacy results from a pre-specified overall survival interim analysis (OS IA2) which was planned to occur 2 years (yrs) after the primary outcome analysis. Methods Pts were randomized (1:1) to receive ET for up to 10 yrs +/- abemaciclib for 2 yrs (study treatment period). High-risk EBC was defined as either ≥4 positive axillary lymph nodes (ALN), or 1-3 ALN with either Grade 3 disease and/or tumor ≥5 cm (Cohort 1). While the proliferation biomarker Ki-67 was centrally assessed in all pts with available tissue sample, an additional smaller group of pts with 1-3+ ALN and central Ki-67 ≥20% as the only high-risk feature were included (Cohort 2). The intent-to-treat (ITT) population consisted of both Cohort 1 (5120 pts) and Cohort 2 (517 pts). Hazard ratios (HR) were estimated using Cox proportional hazard model. Results At a median follow-up of 42 months, all pts were off abemaciclib. IDFS and DRFS data illustrate a sustained benefit beyond the treatment period. In the ITT population, the HR for IDFS was 0.664 (95% CI: 0.578, 0.762) and DRFS was 0.659 (95% CI: 0.567, 0.767). At 4 yrs, this reflected an improvement in IDFS rates from 79.4% to 85.8% (absolute difference 6.4%), and in DRFS rates from 82.5% to 88.4% (absolute difference 5.9%). The continued separation of the curves was associated with an increase in absolute benefit in IDFS 4-year rates compared to 2-and 3-year IDFS rates (absolute difference 2.8% and 4.8% respectively). While OS remained immature, there was a lower number of deaths observed in the abemaciclib plus ET arm compared to the ET alone arm (157 [5.6%] vs 173 [6.1%], HR 0.929 [95% CI: 0.748, 1.153], p = 0.503), suggesting that the robust benefit in IDFS and DRFS began to translate into a numerically favorable OS HR. As previously described, within Cohort 1, a Ki-67 index of ≥20% was associated with a worse prognosis, but similar abemaciclib treatment effects were observed regardless of Ki-67 index. No new safety signals were observed. Conclusion The clinically meaningful benefit of adjuvant abemaciclib added to ET in HR+, HER2-, node-positive, high-risk EBC persists beyond completion of abemaciclib therapy, yielding an increase in absolute IDFS and DRFS benefit at 4 yrs. While OS remains immature at this time, the lower number of deaths in the abemaciclib arm compared to the ET arm suggest that a survival signal favoring abemaciclib is emerging.

Citation Format: Stephen Johnston, Masakazu Toi, Joyce O’Shaughnessy, Priya Rastogi, Mario Campone, Patrick Neven, Chiun Sheng Huang, Jens Huober, Georgina Garnica Jaliffe, Irfan Cicin, Sara Tolaney, Matthew P. Goetz, Hope Rugo, Elżbieta Senkus, Laura Testa, Lucia Del Mastro, Chikako Shimizu, Ran Wei, Ashwin Shahir, Maria Munoz, Belen San Antonio, Valerie Andre, Nadia Harbeck, Miguel Martín. Abemaciclib plus endocrine therapy for HR+, HER2-, node-positive, high-risk early breast cancer: results from a pre-planned monarchE overall survival interim analysis, including 4-year efficacy outcomes [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS1-09.

Abstract P2-23-06: Estrogen receptor-negative progesterone receptor-positive breast cancer is a molecularly distinct group characterized by the down-regulation of genes controlled by ESR1 and SUZ12

Background: Single hormone receptor-positive breast cancers (BCs) display two distinct phenotypes: ER+/PgR– and ER–/PgR+ further stratified by their HER2 status. Their molecular features are not well defined. Our study aimed to identify differentially expressed genes in ER–/PgR+ BCs compared to other phenotypes. Methods: Our cohort comprised 15 ER+/PgR–/HER2–, 11 ER+/PgR–/HER2+, 17 ER–/PgR+/HER2–, 9 ER–/PgR+/HER2+, 5 ER+/PgR+/HER2–, and 5 ER–/PgR–/HER2– invasive BCs collected from 9 Polish and 2 Hungarian centers. The cases were selected from a larger cohort after being matched according to grade, HER2 status, lymph nodes, and distant metastasis status. ER–/PgR+ group was thoroughly validated via immunohistochemistry [Kunc et al. 2022]. The expression of 776 genes was profiled with nCounter® Breast Cancer 360™ Panel in archival formalin-fixed paraffin-embedded tissue samples. A gene was defined as differentially expressed between groups if it met the following criteria: the log2 fold-change in the expression of >1 or ←1 and the p-value < 0.05 (Mann-Whitney U test). Additionally, weighted correlation network analysis (WGCNA) was performed to identify modules of at least 15 highly correlated genes. Subsequently, the association between gene modules and PgR status in ER– subgroup was performed. Identified mRNAs were subjected to functional annotation analysis to determine the top enriched pathways. Results: ER–/PgR+ BCs were characterized by significantly lower expression of ESR1 compared to double-positive (p< 0.001) and ER+/PgR– tumors (p< 0.001), whereas PGR expression was higher compared to ER+/PgR– (p< 0.001), and no significantly different from ER+/PgR+ BCs (p=0.14). Triple-negative BCs had no detectable PGR mRNA. Four genes (MIA, ID4, FOXC1, CDC20) were consistently up-regulated and six genes (FAM214A, MLPH, NFKBIZ, FOS, SLC44A4, SPDEF) were down-regulated in ER–/PgR+/HER2– tumors compared to other HER2– subgroups. Compared to ER+/HER2– BCs, ER–/PgR+/HER2– cases showed up-regulation of 15 genes associated with response to vitamin D, response to ketone, and regulation of transcription, and downregulation of 33 genes involved in response to estrogen, negative regulation of cell population proliferation, regulation of epithelial-mesenchymal transition, and controlled by ESR1 and SUZ12. In WGCNA analysis of the ER– subgroup, PgR status was negatively correlated with 4 gene modules and positively correlated with 1 gene module. In line with differential gene expression analysis, genes negatively correlated with ER–/PgR+ status are regulated by ESR1 and SUZ12 and are involved in the regulation of cell proliferation, extracellular matrix organization, and NOTCH1 signaling. Genes positively correlated with ER–/PgR+ status are regulated by E2F4, FOXM1, SIN3A, NFYB, E2F1, FOS, IRF1, ZMIZ1, and UBTF and participate in cell cycle, regulation of mitosis, and microtubule cytoskeleton regulation. Conclusions: ER–/PgR+ BCs display a distinct mRNA expression profile characterized by the down-regulation of genes controlled by ESR1 and SUZ12. The latter as a part of Polycomb Repressive Complex 2 contributes to chromatin silencing, and some previous studies suggested its role in the regulation of steroid hormone receptors expression. Additionally, ER–/PgR+ BCs overexpress FOXC1 which is linked to more aggressive, high-grade, and treatment-resistant breast cancers. Our data indicate the need to unravel the mechanism of epigenetic regulation of PGR expression, especially its methylation status, in ER–/PgR+ breast cancer.

Citation Format: Michał Kunc, Marta Popęda, Michał Bieńkowski, Marcin Braun, Aleksandra Łacko, Barbara Radecka, Joanna Pikiel, Maria Litwiniuk, Katarzyna Pogoda, Magdalena Niemira, Anna Szałkowska, Ewa Iżycka-Świeszewska, Gabor Cserni, Wojciech Biernat, Elżbieta Senkus. Estrogen receptor-negative progesterone receptor-positive breast cancer is a molecularly distinct group characterized by the down-regulation of genes controlled by ESR1 and SUZ12 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-23-06.

Continuous enzalutamide after progression of metastatic castration-resistant prostate cancer treated with docetaxel (PRESIDE): an international, randomised, phase 3b study

BACKGROUND

Although androgen deprivation therapy is typically given long-term for men with metastatic prostate cancer, second-generation hormone therapies are generally discontinued before the subsequent line of treatment. We aimed to evaluate the efficacy of continuing enzalutamide after progression in controlling metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel and prednisolone.

METHODS

PRESIDE was a two-period, multinational, double-blind, randomised, placebo-controlled, phase 3b study done at 123 sites in Europe (in Austria, Belgium, Czech Republic, France, Germany, Greece, Italy, Netherlands, Norway, Poland, Russia, Spain, Sweden, Switzerland, Turkey, and the UK). Patients were eligible for period 1 (P1) of the study if they had histologically confirmed prostate adenocarcinoma without neuroendocrine differentiation or small-cell features, serum testosterone concentrations of 1·73 nmol/L or less, and had progressed during androgen deprivation therapy with a luteinising hormone-releasing hormone agonist or antagonist or after bilateral orchiectomy. In P1, patients received open-label enzalutamide 160 mg per day orally. At week 13, patients were assessed for either radiographic or prostate-specific antigen (PSA) progression (25% or more increase and 2 ng/mL or more above nadir). Patients who showed any decline in PSA at week 13 and subsequently progressed (radiographic progression, PSA progression, or both) were screened and enrolled in period 2 (P2), during which eligible patients were treated with up to ten cycles of intravenous docetaxel 75 mg/m² every 3 weeks and oral prednisolone 10 mg/day, and randomly assigned (1:1) to oral enzalutamide 160 mg/day or oral placebo. Patients were stratified by type of disease progression. The block size was four and the overall number of blocks was 400. Patients, investigators, and study organisers were masked to treatment assignment. The primary endpoint was progression-free survival analysed in all patients in P2. This trial is registered with ClinicalTrials.gov, NCT02288247, and is no longer recruiting.

FINDINGS

Between Dec 1, 2014, and Feb 15, 2016, 816 patients were screened for P1 of the study. 688 patients were enrolled in P1 and 687 received open-label enzalutamide. In P2, 271 patients were randomly assigned at 73 sites to receive enzalutamide (n=136) or placebo (n=135). The data cutoff for analysis was April 30, 2020. Median progression-free survival with enzalutamide was 9·5 months (95% CI 8·3-10·9) versus 8·3 months (6·3-8·7) with placebo (hazard ratio 0·72 [95% CI 0·53-0·96]; p=0·027). The most common grade 3 treatment-emergent adverse events were neutropenia (17 [13%] of 136 patients in the enzalutamide group vs 12 [9%] of 135 patients in the placebo group) and asthenia (ten [7%] vs six [4%]). The most common grade 4 treatment-emergent adverse event in P2 was neutropenia (23 [17%] of 136 patients in the enzalutamide group vs 28 [21%] of 135 patients in the placebo group). Serious treatment-emergent adverse events were reported in 67 (49%) of 136 patients in the enzalutamide group and 52 (39%) of 135 patients in the placebo group. Two (15%) of 13 deaths in the enzalutamide group (caused by septic shock and haematuria) and one (14%) of seven deaths in the placebo group (caused by actue kidney injury) were associated with docetaxel.

INTERPRETATION

PRESIDE met its primary endpoint and showed that continuing enzalutamide with docetaxel plus androgen deprivation therapy delayed time to progression compared with docetaxel plus androgen deprivation therapy alone, supporting the hypothesis that enzalutamide maintenance could control persistent androgen-dependent clones in men with mCRPC who progress after treatment with enzalutamide alone.

FUNDING

Astellas Pharma and Pfizer.

ESO-ESMO fifth international consensus guidelines for breast cancer in young women (BCY5)

We dedicate this manuscript in memory of a dear friend and colleague Bella Kaufman. The fifth International Consensus Symposium for Breast Cancer in Young Women (BCY5) took place virtually in October 2020, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY4 with incorporation of new evidence to inform the guidelines. Areas of research priorities as well as specificities in different geographic and minority populations were identified. This manuscript summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Current and future diagnostic and treatment strategies for patients with invasive lobular breast cancer

BACKGROUND

Invasive lobular breast cancer (ILC) is the second most common type of breast cancer after invasive breast cancer of no special type (NST), representing up to 15% of all breast cancers.

DESIGN

Latest data on ILC are presented, focusing on diagnosis, molecular make-up according to the European Society for Medical Oncology Scale for Clinical Actionability of molecular Targets (ESCAT) guidelines, treatment in the early and metastatic setting and ILC-focused clinical trials.

RESULTS

At the imaging level, magnetic resonance imaging-based and novel positron emission tomography/computed tomography-based techniques can overcome the limitations of currently used imaging techniques for diagnosing ILC. At the pathology level, E-cadherin immunohistochemistry could help improving inter-pathologist agreement. The majority of patients with ILC do not seem to benefit as much from (neo-)adjuvant chemotherapy as patients with NST, although chemotherapy might be required in a subset of high-risk patients. No differences in treatment efficacy are seen for anti-human epidermal growth factor receptor 2 (HER2) therapies in the adjuvant setting and cyclin-dependent kinases 4 and 6 inhibitors in the metastatic setting. The clinical utility of the commercially available prognostic gene expression-based tests is unclear for patients with ILC. Several ESCAT alterations differ in frequency between ILC and NST. Germline BRCA1 and PALB2 alterations are less frequent in patients with ILC, while germline CDH1 (gene coding for E-cadherin) alterations are more frequent in patients with ILC. Somatic HER2 mutations are more frequent in ILC, especially in metastases (15% ILC versus 5% NST). A high tumour mutational burden, relevant for immune checkpoint inhibition, is more frequent in ILC metastases (16%) than in NST metastases (5%). Tumours with somatic inactivating CDH1 mutations may be vulnerable for treatment with ROS1 inhibitors, a concept currently investigated in early and metastatic ILC.

CONCLUSION

ILC is a unique malignancy based on its pathological and biological features leading to differences in diagnosis as well as in treatment response, resistance and targets as compared to NST.

Management Strategies for Hyperglycemia Associated with the α-Selective PI3K Inhibitor Alpelisib for the Treatment of Breast Cancer

Alpelisib is an α-selective phosphatidylinositol 3-kinase inhibitor used for treating hormone receptor-positive (HR+), human epidermal growth receptor 2-negative (HER2-), PIK3CA-mutated locally advanced or metastatic breast cancer following disease progression on or after endocrine therapy. Hyperglycemia is an on-target effect of alpelisib affecting approximately 60% of treated patients, and sometimes necessitating dose reductions, treatment interruptions, or discontinuation of alpelisib. Early detection of hyperglycemia and timely intervention have a key role in achieving optimal glycemic control and maintaining alpelisib dose intensity to optimize the benefit of this drug. A glycemic support program implemented by an endocrinology-oncology collaborative team may be very useful in this regard. Lifestyle modifications, mainly comprising a reduced-carbohydrate diet, and a designated stepwise, personalized antihyperglycemic regimen, based on metformin, sodium-glucose co-transporter 2 inhibitors, and pioglitazone, are the main tools required to address the insulin-resistant hyperglycemia induced by alpelisib. In this report, based on the consensus of 14 oncologists and seven endocrinologists, we provide guidance for hyperglycemia management strategies before, during, and after alpelisib therapy for HR+, HER2-, PIK3CA-mutated breast cancer, with a focus on a proactive, multidisciplinary approach.

High expression of progesterone receptor may be an adverse prognostic factor in oestrogen receptor-negative/progesterone receptor-positive breast cancer: results of comprehensive re-evaluation of multi-institutional case series

Oestrogen receptor (ER)-negative (-) progesterone receptor (PgR)-positive (+) is the least common combination of steroid receptor expression observed in breast cancer. There are many controversies regarding the actual existence of ER-/PgR+ phenotype. In the current study, we aimed to perform comprehensive immunohistochemical re-evaluation of ER-/PgR+ breast cancers from multiple institutions. A total of 135 cases of ER-/PgR+ breast cancer were collected from 11 institutions from the period 2006-2020 and subsequently stained with three clinically validated anti-ER antibody clones: SP1 (Roche), 1D5 (Dako), and EP1 (Dako), and two anti-PgR antibody clones: 636 (Dako), and 1E2 (Roche). Clinicopathological characteristics of confirmed and re-categorised cases were analysed. Seventy-six cases retained the original ER-/PgR+ phenotype, including 21 HER2+ and 55 HER2- tumours. Forty-seven cases were ER+ with at least one anti-ER antibody, and 12 cases were re-categorised as double-negatives across all anti-ER and anti-PgR antibodies. No significant differences in survival were observed between groups in the HER2+ category. In the HER2- cohort, confirmed ER-/PgR+, ER+ tumours with discrepant ER staining, and triple negatives had inferior overall survival compared to concordant ER+ cases. Progesterone receptor expression in >20% of cells was identified as an adverse prognostic factor in ER-/PgR+/HER2- breast cancer in a multivariable model adjusted by stage (HR 5.0, 95% CI 1.3-19.2, p=0.019). We performed one of the largest validation studies so far on ER-/PgR+ breast cancer and confirmed the existence of this subgroup. Moreover, we identified high PgR expression as an adverse prognostic factor.

European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus recommendations on patient selection and dose and fractionation for external beam radiotherapy in early breast cancer

High-quality randomised clinical trials testing moderately fractionated breast radiotherapy have clearly shown that local control and survival is at least as effective as with 2 Gy daily fractions with similar or reduced normal tissue toxicity. Fewer treatment visits are welcomed by patients and their families, and reduced fractions produce substantial savings for health-care systems. Implementation of hypofractionation, however, has moved at a slow pace. The oncology community have now reached an inflection point created by new evidence from the FAST-Forward five-fraction randomised trial and catalysed by the need for the global radiation oncology community to unite during the COVID-19 pandemic and rapidly rethink hypofractionation implementation. The aim of this paper is to support equity of access for all patients to receive evidence-based breast external beam radiotherapy and to facilitate the translation of new evidence into routine daily practice. The results from this European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus state that moderately hypofractionated radiotherapy can be offered to any patient for whole breast, chest wall (with or without reconstruction), and nodal volumes. Ultrafractionation (five fractions) can also be offered for non-nodal breast or chest wall (without reconstruction) radiotherapy either as standard of care or within a randomised trial or prospective cohort. The consensus is timely; not only is it a pragmatic framework for radiation oncologists, but it provides a measured proposal for the path forward to influence policy makers and empower patients to ensure equity of access to evidence-based radiotherapy.

Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study

BACKGROUND

Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis.

PATIENTS AND METHODS

This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety.

RESULTS

At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile.

CONCLUSION

Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

De-escalation of axillary irradiation for early breast cancer - Has the time come?

Introduction of sentinel lymph node biopsy, initially in clinically node-negative and subsequently in patients presenting with involved axilla and downstaged by primary systemic therapy, allowed for significant decrease in morbidity compared to axillary lymph node dissection. Concurrently, regional nodal irradiation was demonstrated to improve outcomes in most node-positive patients. Additionally, over the last decades, introduction of more effective systemic therapies has resulted in improvements not only at distant sites, but also in locoregional control, creating space for de-escalation of locoregional treatments. We discuss the data on de-escalation in axillary surgery and irradiation, both in patients undergoing upfront surgery and primary systemic therapy, with special emphasis on the feasibility of omission of nodal irradiation in patients undergoing primary systemic therapy. In view of the accumulating evidence, omission of axillary irradiation may be considered in clinically node-positive patients converting after primary systemic therapy to pathologically negative nodes on sentinel lymph node biopsy (preferably also with in-breast pCR), presenting with lower initial nodal stage, older age and were treated with breast-conserving surgery followed by whole breast irradiation. Omission of regional nodal irradiation in patients with aggressive tumor phenotypes achieving a pCR is under investigation. In patients undergoing preoperative endocrine therapy the adoption of axillary management strategies utilized in case of upfront surgery seems more suitable than those used in post chemotherapy-based primary systemic therapy setting.

Lost but Not Least-Novel Insights into Progesterone Receptor Loss in Estrogen Receptor-Positive Breast Cancer

Estrogen receptor α (ERα) and progesterone receptor (PgR) are crucial prognostic and predictive biomarkers that are usually co-expressed in breast cancer (BC). However, 12-24% of BCs present ERα(+)/PgR(-) phenotype at immunohistochemical evaluation. In fact, BC may either show primary PgR(-) status (in chemonaïve tumor sample), lose PgR expression during neoadjuvant treatment, or acquire PgR(-) phenotype in local relapse or metastasis. The loss of PgR expression in ERα(+) breast cancer may signify resistance to endocrine therapy and poorer outcomes. On the other hand, ERα(+)/PgR(-) BCs may have a better response to neoadjuvant chemotherapy than double-positive tumors. Loss of PgR expression may be a result of pre-transcriptional alterations (copy number loss, mutation, epigenetic modifications), decreased transcription of the PGR gene (e.g., by microRNAs), and post-translational modifications (e.g., phosphorylation, sumoylation). Various processes involved in the down-regulation of PgR have distinct consequences on the biology of cancer cells. Occasionally, negative PgR status detected by immunohistochemical analysis is paradoxically associated with enhanced transcriptional activity of PgR that might be inhibited by antiprogestin treatment. Identification of the mechanism of PgR loss in each patient seems challenging, yet it may provide important information on the biology of the tumor and predict its responsiveness to the therapy.

Analysis of mutation status and homologous recombination deficiency in tumors of patients with germline BRCA1 or BRCA2 mutations and metastatic breast cancer: OlympiAD

BACKGROUND

Presence of a germline BRCA1 and/or BRCA2 mutation (gBRCAm) may sensitize tumors to poly(ADP-ribose) polymerase (PARP) inhibition via inactivation of the second allele, resulting in gene-specific loss of heterozygosity (gsLOH) and homologous recombination deficiency (HRD). Here we explore whether tissue sample testing provides an additional route to germline testing to inform treatment selection for PARP inhibition.

PATIENTS AND METHODS

In this prespecified exploratory analysis, BRCA1 and/or BRCA2 mutations in blood samples (gBRCAm) and tumor tissue (tBRCAm) were analyzed from patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer and known gBRCAm, enrolled in the phase III OlympiAD trial. The frequency and nature of tBRCAm, HRD score status [HRD-positive (score ≥42) versus HRD-negative (score <42) using the Myriad myChoice® CDx test] and rates of gsLOH were determined, and their impact on clinical efficacy (objective response rate and progression-free survival) was explored.

RESULTS

Tissue samples from 161/302 patients yielded tBRCAm, HRD and gsLOH data for 143 (47%), 129 (43%) and 125 (41%) patients, respectively. Concordance between gBRCAm and tBRCAm was 99%. gsLOH was observed in 118/125 (94%) patients [BRCA1m, 73/76 (96%); BRCA2m, 45/49 (92%)]. A second mutation event was recorded for two of the three BRCA1m patients without gsLOH. The incidence of HRD-negative was 16% (21/129) and was more common for BRCA2m (versus BRCA1m) and/or for hormone receptor-positive (versus triple-negative) disease. Olaparib antitumor activity was observed irrespective of HRD score.

CONCLUSIONS

gBRCAm identified in patients with HER2-negative metastatic breast cancer by germline testing in blood was also identified by tumor tissue testing. gsLOH was common, indicating a high rate of biallelic inactivation in metastatic breast cancer. Olaparib activity was seen regardless of gsLOH status or HRD score. Thus, additional tumor testing to inform PARP inhibitor treatment selection may not be supported for these patients.

Systematic review of real-world studies evaluating the impact of medication non-adherence to endocrine therapies on hard clinical endpoints in patients with non-metastatic breast cancer

Breast cancer, one of the most common malignancies, is associated with significant economic and health burden both at the patient and societal level. Although medication non-adherence to endocrine breast cancer therapies is common, so far only limited systematic evidence has been available on its quantitative consequences, as previous systematic reviews focused mainly on factors contributing to medication non-adherence. The objective of this review was to explore the implications of medication non-adherence to endocrine therapies on hard clinical outcomes in breast cancer based on real-world studies. A systematic literature review was conducted on PubMed; empirical evidence on hard clinical endpoints (i.e., survival, disease-free survival, metastasis and recurrence) were extracted from uni- or multivariate statistical analyses from retrospective or prospective cohort studies. Of the 2,360 identified records, 12 studies met the inclusion criteria. Two studies identified significant positive association between medication non-adherence and the risk of distant metastasis, three articles between medication non-adherence and the recurrence of breast cancer, two studies between medication non-adherence- and non-persistence and of worse disease-free survival and eight articles between medication non-adherence and mortality. There was only one study where the positive association between medication adherence and survival did not apply to all subgroups. The strong evidence on the negative health consequences of non-adherence to breast cancer treatments indicates the need for the regular monitoring of medication adherence. Furthermore, explicit inclusion of adherence enhancing interventions into health policy agenda would be warranted to improve medication adherence also at a system level.

Adjuvant Olaparib for Patients with BRCA1- or BRCA2-Mutated Breast Cancer

BACKGROUND

Poly(adenosine diphosphate-ribose) polymerase inhibitors target cancers with defects in homologous recombination repair by synthetic lethality. New therapies are needed to reduce recurrence in patients with BRCA1 or BRCA2 germline mutation-associated early breast cancer.

METHODS

We conducted a phase 3, double-blind, randomized trial involving patients with human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with BRCA1 or BRCA2 germline pathogenic or likely pathogenic variants and high-risk clinicopathological factors who had received local treatment and neoadjuvant or adjuvant chemotherapy. Patients were randomly assigned (in a 1:1 ratio) to 1 year of oral olaparib or placebo. The primary end point was invasive disease-free survival.

RESULTS

A total of 1836 patients underwent randomization. At a prespecified event-driven interim analysis with a median follow-up of 2.5 years, the 3-year invasive disease-free survival was 85.9% in the olaparib group and 77.1% in the placebo group (difference, 8.8 percentage points; 95% confidence interval [CI], 4.5 to 13.0; hazard ratio for invasive disease or death, 0.58; 99.5% CI, 0.41 to 0.82; P<0.001). The 3-year distant disease-free survival was 87.5% in the olaparib group and 80.4% in the placebo group (difference, 7.1 percentage points; 95% CI, 3.0 to 11.1; hazard ratio for distant disease or death, 0.57; 99.5% CI, 0.39 to 0.83; P<0.001). Olaparib was associated with fewer deaths than placebo (59 and 86, respectively) (hazard ratio, 0.68; 99% CI, 0.44 to 1.05; P = 0.02); however, the between-group difference was not significant at an interim-analysis boundary of a P value of less than 0.01. Safety data were consistent with known side effects of olaparib, with no excess serious adverse events or adverse events of special interest.

CONCLUSIONS

Among patients with high-risk, HER2-negative early breast cancer and germline BRCA1 or BRCA2 pathogenic or likely pathogenic variants, adjuvant olaparib after completion of local treatment and neoadjuvant or adjuvant chemotherapy was associated with significantly longer survival free of invasive or distant disease than was placebo. Olaparib had limited effects on global patient-reported quality of life. (Funded by the National Cancer Institute and AstraZeneca; OlympiA ClinicalTrials.gov number, NCT02032823.).

Comparison of claudin-3 and claudin-4 expression in bilateral and unilateral breast cancer

Claudins are essential components of tight junctions, which are frequently deregulated in breast cancer. The aim of the current study was to assess claudin-3 and -4 expression in bilateral breast cancer (BBC) and unilateral breast cancer (UBC). Immunohistochemical expression of claudin-3 and claudin-4 was evaluated in tissue microarrays containing 174 cases of BBCs paired with 174 cases of solitary tumors. Each case was classified as claudin-high or claudin-low depending on the H-score value. The results were correlated with histopathological features and the expression of basic breast cancer biomarkers. Median H-scores for claudin-3 were significantly higher in the synchronous BBC (sBBC) than in UBC. Claudin-4-high cases were more prevalent than within the whole BBC group, and sBBC and metachronous BBC (mBBC) alone. In the BBC group negative ER, high Ki-67 and high claudin-3 were independent factors correlated with high claudin-4. In the UBC group, Ki-67 >14% and high claudin-3 were associated with high claudin-4. Our study demonstrates that the expression of claudin-4 is significantly higher in UBC compared to BBC tumors. We also demonstrated that high claudin-4 expression in BBC is associated with a more aggressive phenotype (lack of steroid receptors, HER2 overexpression, and high Ki-67). It is possible that claudins down- and upregulation may depend on different triggers and lead to various consequences in UBC and BBC.

ESO-ESMO 4th International Consensus Guidelines for Breast Cancer in Young Women (BCY4)

The 4th International Consensus Conference for Breast Cancer in Young Women (BCY4) took place in October 2018, in Lugano, Switzerland, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY3 with incorporation of new evidence to inform the guidelines. Areas of research priorities were also identified. This article summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Abstract PD4-03: OlympiAD extended follow-up for overall survival and safety: Olaparib versus chemotherapy treatment of physician’s choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer

Background: In the OlympiAD study, olaparib showed a clinically meaningful benefit in progression-free survival compared with chemotherapy treatment of physician’s choice (TPC) in patients with a germline BRCA1 and/or BRCA2 mutation (BRCAm) and HER2-negative metastatic breast cancer (mBC; Robson N Engl J Med 2017). Final prespecified median overall survival (OS) at 64% data maturity was 19.3 months with olaparib versus 17.1 months with TPC (Robson Ann Oncol 2019). At this time, 26 patients continued to receive olaparib, with none continuing to receive TPC as assigned. After consenting to a protocol amendment, post hoc follow-up of patients for survival status and serious adverse events continued.

Patients and methods: OlympiAD is a Phase III, randomized, controlled, open-label trial (NCT02000622). Patients with a germline BRCAm and HER2-negative mBC who had received ≤2 prior lines of chemotherapy for mBC were randomized to olaparib tablets (300 mg twice daily) or predeclared TPC (capecitabine, vinorelbine or eribulin). Extended OS and safety follow-up were exploratory endpoints; the study was not powered to detect an OS benefit or treatment effect between subgroups. The overall hazard ratio (HR) was estimated using a stratified log-rank test, and a single Cox proportional hazards model was used for analyses in prespecified subgroups.

Results: Of patients randomized to olaparib (n=205) or TPC (n=97), 160 (78.0%) and 80 patients (82.5%) respectively had withdrawn from the study (majority due to death), and seven and eight patients, respectively, did not participate in the extended follow-up. At data cut-off (March 3, 2019), 223 patients had died (73.8% data maturity), 24 (11.7%) patients from the olaparib arm and nine patients (9.3%) from the TPC arm were continuing the study off treatment, no patients were continuing to receive TPC as assigned. Fourteen patients (6.8%) were continuing olaparib at this time; in this small number of patients at baseline their median age was 42.5 years, 42.9% had not received prior chemotherapy for mBC, 57.1% were TNBC, 50.0% had a BRCA1 mutation, 42.9% had liver metastasis and 57.1% had ≥2 metastatic sites. Median follow-up was 18.9 months in the olaparib arm and 15.5 months in the TPC arm (40.7 and 29.2 months in censored patients, respectively). OS and landmark analyses for the overall population and prespecified key subgroups are reported in the Table. Of patients who discontinued study treatment, 2.0% in the olaparib arm and 11.3% in the TPC arm received subsequent PARP inhibitors, and 42.4% and 48.5%, respectively, received subsequent platinum chemotherapy. Median total study treatment duration was 251 days in the olaparib arm versus 105 days in the TPC arm, with 8.8% of olaparib patients receiving treatment for &gt;3 years versus no TPC patients. During the extended follow-up period, there were no new serious adverse events suspected to be related to olaparib treatment, including no reports of myelodysplastic syndrome/acute myeloid leukemia.

Table. Overall survivalNo. of events (%)Median OS (months)HR (95% CI)Survival (%)12 months24 months36 months48 monthsOverall populationOlaparib (N=205)150 (73.2)19.30.84 (0.63–1.12)72.739.027.918.9TPC (N=97)73 (75.3)17.169.239.121.214.2ER/PgR positiveOlaparib (N=103)68 (66.0)21.80.79 (0.53–1.19)80.246.735.623.1TPC (N=49)36 (73.5)21.376.548.129.117.4TNBCOlaparib (102)82 (80.4)17.40.87 (0.59–1.29)65.131.220.215.4TPC (N=48)37 (77.1)14.961.629.711.911.9No prior chemotherapy for mBC (first line)Olaparib (N=59)39 (66.1)22.60.54 (0.32–0.92)76.048.140.824.6TPC (N=28)22 (78.6)14.765.426.912.812.8With prior chemotherapy for mBC (second or third line)Olaparib (N=146)111 (76.0)18.81.00 (0.72–1.40)71.435.222.417.1TPC (N=69)51 (73.9)17.270.844.124.714.8With prior platinumOlaparib (N=60)47 (78.3)17.20.74 (0.45–1.25)64.430.216.816.8TPC (N=26)22 (84.6)13.357.228.612.3NCWithout prior platinumOlaparib (N=145)103 (71.0)20.30.86 (0.62–1.21)76.142.532.420.4TPC (N=71)51 (71.8)19.673.943.125.516.3CI, confidence interval; ER, estrogen receptor; HR, hazard ratio; NC, not calculable; PgR, progesterone receptor; TNBC, triple-negative breast cancer

Conclusions: Total treatment duration was more than double for olaparib versus TPC, with no new safety findings over long-term treatment. With extended follow-up, OS did not differ significantly between treatment arms; however, continued OS benefit was suggested for olaparib versus chemotherapy for patients in the first-line setting for mBC.

Citation Format: Mark Robson, Seock-Ah Im, Elżbieta Senkus, Binghe Xu, Susan Domchek, Norikazu Masuda, Suzette Delaloge, Wei Li, Nadine Tung, Anne Armstrong, Wendy Bannister, Carsten Goessl, Allison Allen, Pierfranco Conte. OlympiAD extended follow-up for overall survival and safety: Olaparib versus chemotherapy treatment of physician’s choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer [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 PD4-03.

Patient-reported outcomes in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer receiving olaparib versus chemotherapy in the OlympiAD trial

BACKGROUND

The phase III OlympiAD study (NCT02000622) showed a statistically significant progression-free survival benefit with olaparib versus chemotherapy treatment of physician's choice (TPC) in patients with a germline BRCA mutation and human epidermal growth factor receptor 2-negative metastatic breast cancer. From this study, we report the effect of olaparib on health-related quality of life (HRQoL).

METHODS

Patients were randomised 2:1 to olaparib monotherapy (300 mg twice daily) or single-agent TPC. The primary HRQoL end-point was mean change from baseline in the two-item global health status/QoL score determined from patient-completed European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item module (EORTC QLQ-C30) questionnaires and assessed using a mixed model for repeated measures. Symptoms and functioning domains, best overall response and time to deterioration of QoL were also evaluated.

RESULTS

Overall questionnaire compliance rates were 93.2% for olaparib and 76.3% for TPC. Between-treatment global health status/QoL comparison showed a significant improvement in the olaparib arm versus the TPC arm, with mean change of 3.9 (standard deviation 1.2) versus -3.6 (2.2), a difference of 7.5 points (95% confidence interval [CI]: 2.48, 12.44; P = 0.0035). A higher proportion of patients in the olaparib arm showed a best overall response of 'improvement' in global health status/QoL (33.7% vs 13.4%). Median time to global health status/QoL deterioration was not reached in olaparib patients and was 15.3 months for TPC patients (hazard ratio: 0.44 [95% CI: 0.25, 0.77]; P = 0.004). For EORTC QLQ-C30 symptoms and functioning subscales, only nausea/vomiting symptom score was worse in the olaparib arm than in the TPC arm (across all visits compared with baseline).

CONCLUSION

HRQoL was consistently improved for patients treated with olaparib, compared with chemotherapy TPC.

OlympiAD final overall survival and tolerability results: Olaparib versus chemotherapy treatment of physician's choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer

BACKGROUND

In the OlympiAD study, olaparib was shown to improve progression-free survival compared with chemotherapy treatment of physician's choice (TPC) in patients with a germline BRCA1 and/or BRCA2 mutation (BRCAm) and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (mBC). We now report the planned final overall survival (OS) results, and describe the most common adverse events (AEs) to better understand olaparib tolerability in this population.

PATIENTS AND METHODS

OlympiAD, a Phase III, randomized, controlled, open-label study (NCT02000622), enrolled patients with a germline BRCAm and HER2-negative mBC who had received ≤2 lines of chemotherapy for mBC. Patients were randomized to olaparib tablets (300 mg bid) or predeclared TPC (capecitabine, vinorelbine, or eribulin). OS and safety were secondary end points.

RESULTS

A total of 205 patients were randomized to olaparib and 97 to TPC. At 64% data maturity, median OS was 19.3 months with olaparib versus 17.1 months with TPC (HR 0.90, 95% CI 0.66-1.23; P = 0.513); median follow-up was 25.3 and 26.3 months, respectively. HR for OS with olaparib versus TPC in prespecified subgroups were: prior chemotherapy for mBC [no (first-line setting): 0.51, 95% CI 0.29-0.90; yes (second/third-line): 1.13, 0.79-1.64]; receptor status (triple negative: 0.93, 0.62-1.43; hormone receptor positive: 0.86, 0.55-1.36); prior platinum (yes: 0.83, 0.49-1.45; no: 0.91, 0.64-1.33). Adverse events during olaparib treatment were generally low grade and manageable by supportive treatment or dose modification. There was a low rate of treatment discontinuation (4.9%), and the risk of developing anemia did not increase with extended olaparib exposure.

CONCLUSIONS

While there was no statistically significant improvement in OS with olaparib compared to TPC, there was the possibility of meaningful OS benefit among patients who had not received chemotherapy for metastatic disease. Olaparib was generally well-tolerated, with no evidence of cumulative toxicity during extended exposure. Please see the article online for additional video content.

Abstract CT038: OlympiAD final overall survival: Olaparib versus chemotherapy treatment of physician's choice (TPC) in patients with HER2-negative metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm)

Background: A significant progression-free survival benefit was shown in OlympiAD (NCT02000622) for patients (pts) with HER2-negative mBC and a gBRCAm receiving olaparib vs TPC (hazard ratio [HR] 0.58; 95% confidence interval [CI], 0.43, 0.80; P&lt;0.001). Interim overall survival (OS) data were reported at primary analysis (46% maturity); prespecified final OS data are now reported.

Methods: OlympiAD was a randomized Phase III trial in pts with HER2-negative mBC and a gBRCAm who had received ≤2 lines of chemotherapy for mBC. Randomization (2:1) to olaparib tablet monotherapy (300 mg bid) or single-agent TPC (capecitabine, vinorelbine or eribulin) was stratified by prior chemotherapy (no/yes), prior platinum (no/yes) and receptor status (ER+ and/or PR+ vs TNBC). Data cut-off was 25 September 2017.

Results: Of 302 randomized pts, 205 received olaparib and 91 received TPC (6 TPC pts declined treatment). At final OS analysis, 192/302 deaths had occurred (64% maturity). HR for OS in the olaparib vs TPC group was 0.90 (95% CI 0.66, 1.23; P=NS; median 19.3 months [mo] vs 17.1 mo). Median follow-up for OS was 18.9 mo for olaparib vs 15.5 mo in the TPC group. More pts in the TPC group received subsequent therapy with PARP inhibitors, cytotoxic chemotherapy, platinum and hormonal treatment than in the olaparib group. Predefined subgroup analyses are shown for the three stratification factors (Table).

SubgroupMedian OS (months)HR95% CINominal P*OlaparibTPCPrior chemotherapy for mBCNo (1L)22.614.70.510.29, 0.900.02Yes (2L/3L)18.817.21.130.79, 1.640.52Prior platinum for BCNo20.319.60.910.64, 1.330.63Yes17.213.30.830.49, 1.450.49Receptor statusER+ and/or PR+21.821.30.860.55, 1.360.51TNBC17.414.90.930.62, 1.430.75*Nominal P-values were calculated using a likelihood ratio test; OS stratification factors were prespecified but not alpha-controlled. 1L, first line; 2L, second line; 3L, third line; BC, breast cancer; ER, estrogen receptor; PR, progesterone receptor; TNBC, triple negative breast cancer CTCAE grade ≥3 adverse events were reported in 38 and 50% of pts receiving olaparib or TPC, respectively, at extended safety analysis. 39 (19%) pts and 15 (7%) pts received olaparib for &gt;18 mo and &gt;24 mo, respectively. Conclusions: At final analysis, median OS was 2.2 mo longer for olaparib monotherapy vs TPC in the overall population (not statistically significant). OlympiAD was not powered to show an OS difference for olaparib vs TPC. Benefit appeared greatest in pts with no prior chemotherapy for mBC (7.9 mo longer median OS in olaparib pts vs TPC). Olaparib safety profile was consistent with primary analysis indicating no relevant cumulative toxicity with extended exposure. Citation Format: Mark E. Robson, Seock-Ah Im, Elżbieta Senkus, Binghe Xu, Susan Domchek, Norikazu Masuda, Suzette Delaloge, Wei Li, Nadine Tung, Anne Armstrong, Wenting Wu, Carsten Goessl, Sarah Runswick, Pierfranco Conte. OlympiAD final overall survival: Olaparib versus chemotherapy treatment of physician's choice (TPC) in patients with HER2-negative metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT038.

Borealis-1: a randomized, first-line, placebo-controlled, phase II study evaluating apatorsen and chemotherapy for patients with advanced urothelial cancer

Background

Five-year survival of patients with inoperable, advanced urothelial carcinoma treated with the first-line chemotherapy is 5%-15%. We assessed whether the Hsp27 inhibitor apatorsen combined with gemcitabine plus cisplatin (GC) could improve overall survival (OS) in these patients.

Patients and methods

This placebo-controlled, double-blind, phase II trial randomized 183 untreated urothelial carcinoma patients (North America and Europe) to receive GC plus either placebo (N = 62), 600 mg apatorsen (N = 60), or 1000 mg apatorsen (N = 61). In the experimental arm, treatment included loading doses of apatorsen followed by up to six cycles of apatorsen plus GC. Patients receiving at least four cycles could continue apatorsen monotherapy as maintenance until progression or unacceptable toxicity. The primary end point was OS.

Results

OS was not significantly improved in the single or combined 600- or 1000-mg apatorsen arms versus placebo [hazard ratio (HR), 0.86 and 0.90, respectively]. Exploratory study of specific statistical modeling showed a trend for improved survival in patients with baseline poor prognostic features treated with 600 mg apatorsen compared with placebo (HR = 0.72). Landmark analysis of serum Hsp27 (sHsp27) levels showed a trend toward survival benefit for poor-prognosis patients in 600- and 1000-mg apatorsen arms who achieved lower area under the curve sHsp27 levels, compared with the placebo arm (HR = 0.45 and 0.62, respectively). Higher baseline circulating tumor cells (≥5 cells/7.5 ml) was observed in patients with poor prognosis in correlation with poor survival. Treatment-emergent adverse events were manageable and more common in both apatorsen-treatment arms.

Conclusions

Even though apatorsen combined with standard chemotherapy did not demonstrate a survival benefit in the overall study population, patients with poor prognostic features might benefit from this combination. Serum Hsp27 levels may act as a biomarker to predict treatment outcome. Further exploration of apatorsen in poor-risk patients is warranted.

Olaparib for Metastatic Breast Cancer in Patients with a Germline BRCA Mutation

BACKGROUND

Olaparib is an oral poly(adenosine diphosphate-ribose) polymerase inhibitor that has promising antitumor activity in patients with metastatic breast cancer and a germline BRCA mutation.

METHODS

We conducted a randomized, open-label, phase 3 trial in which olaparib monotherapy was compared with standard therapy in patients with a germline BRCA mutation and human epidermal growth factor receptor type 2 (HER2)-negative metastatic breast cancer who had received no more than two previous chemotherapy regimens for metastatic disease. Patients were randomly assigned, in a 2:1 ratio, to receive olaparib tablets (300 mg twice daily) or standard therapy with single-agent chemotherapy of the physician's choice (capecitabine, eribulin, or vinorelbine in 21-day cycles). The primary end point was progression-free survival, which was assessed by blinded independent central review and was analyzed on an intention-to-treat basis.

RESULTS

Of the 302 patients who underwent randomization, 205 were assigned to receive olaparib and 97 were assigned to receive standard therapy. Median progression-free survival was significantly longer in the olaparib group than in the standard-therapy group (7.0 months vs. 4.2 months; hazard ratio for disease progression or death, 0.58; 95% confidence interval, 0.43 to 0.80; P<0.001). The response rate was 59.9% in the olaparib group and 28.8% in the standard-therapy group. The rate of grade 3 or higher adverse events was 36.6% in the olaparib group and 50.5% in the standard-therapy group, and the rate of treatment discontinuation due to toxic effects was 4.9% and 7.7%, respectively.

CONCLUSIONS

Among patients with HER2-negative metastatic breast cancer and a germline BRCA mutation, olaparib monotherapy provided a significant benefit over standard therapy; median progression-free survival was 2.8 months longer and the risk of disease progression or death was 42% lower with olaparib monotherapy than with standard therapy. (Funded by AstraZeneca; OlympiAD ClinicalTrials.gov number, NCT02000622 .).

OlympiAD: Phase III trial of olaparib monotherapy versus chemotherapy for patients (pts) with HER2-negative metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm)

LBA4

Background: Olaparib is an oral PARP inhibitor with anti-tumor activity in HER2-negative mBC with a g BRCAm (NCT00494234). OlympiAD (NCT02000622) was a randomized, open-label, phase III study that assessed efficacy and safety of olaparib vs standard single agent chemotherapy treatment of physician’s choice (TPC) in pts with HER2-negative mBC and a g BRCAm. Methods: Pts aged ≥18 y with HER2-negative mBC (hormone receptor positive or triple negative [TN]) and a g BRCAm, who had received ≤2 chemotherapy lines for mBC, were randomized (2:1) to olaparib tablets (300 mg po bid) or TPC (21-day cycles of either capecitabine [2500 mg/m2 po days 1–14], vinorelbine [30 mg/m2 IV days 1 and 8] or eribulin [1.4 mg/m2IV days 1 and 8]). Treatment was continued until objective disease progression (RECIST v1.1) or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) assessed by blinded independent central review (BICR). Results: 302 pts were randomized (median age 44 y; 50% TN; 71% prior chemotherapy for mBC; 28% prior platinum) of whom 205 received olaparib and 91 received TPC (6 TPC pts were not treated). At 77% data maturity, PFS by BICR was significantly longer in pts treated with olaparib vs TPC (HR 0.58; 95% CI 0.43, 0.80; P=0.0009; 7.0 vs 4.2 months, respectively). Time to second progression (investigator-assessed) was also longer in the olaparib arm (HR 0.57; 95% CI 0.40, 0.83). Objective response rate was 59.9 and 28.8% in olaparib and TPC arms, respectively. Grade ≥3 adverse events (AE) occurred in 36.6 and 50.5% of olaparib and TPC pts, with AEs leading to discontinuation in 4.9 and 7.7% of pts, respectively. Mean change from baseline in global health-related quality of life (HRQoL, EORTC-QLQ-C30) across all timepoints favored olaparib (difference vs TPC 7.5; 95% CI 2.48, 12.44; P=0.0035). Conclusions: Olaparib tablet monotherapy provided a statistically significant and clinically meaningful PFS benefit to HER2-negative mBC pts with a g BRCAm, compared to standard TPC. The safety profile of olaparib was consistent with prior studies. The efficacy benefit was seen beyond the first progression and HRQoL also improved. Clinical trial information: NCT02000622.

OlympiAD: Phase III trial of olaparib monotherapy versus chemotherapy for patients (pts) with HER2-negative metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm)

LBA4

The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Sunday, June 4, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

Are synchronous and metachronous bilateral breast cancers different? An immunohistochemical analysis focused on cell cycle regulation

INTRODUCTION

The biology and pathomechanisms of bilateral breast cancers is not fully understood. We compared the morphological and immunohistochemical characteristics of primary tumors in patients with synchronous (sBBC) and metachronous bilateral breast cancers (mBBC), with special focus on cell cycle regulation and its correlation with markers determining intrinsic phenotype.

METHODS

Immunohistochemical expression of p16Ink4A, p21(WAF1/CIP1), p27Kip1, p53, cyclin A, cyclin B, cyclin D1, cyclin D3 and cyclin E was assessed in tissue microarrays containing primary breast tumor cores from 113 mBBC and 61 sBBC. Expression of these markers was correlated with tumor grade and expression of estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2) and Ki-67.

RESULTS

In univariate analysis, mBBC demonstrated higher expression of p16Ink4A (both cytoplasmic: p=0.002 and nuclear: p=0.014), cyclin A (p=0.024) and B (cytoplasmic; p=0.015). In multivariate analysis mBBC were associated with lower expression of p21: p=0.038 and higher cytoplasmic expression of cyclin B: p=0.019. Lower ER expression for all BBCs and mBBC, respectively, was associated with stronger p16 expression (cytoplasmic: both p<0.000001 and nuclear: p<0.000001, p=0.00002), p53: p<0.000001, p=0.000001, cyclin A: p=0.00002, p=0.00045, cyclin B (cytoplasmic: p=0.00037, 0.00015 and nuclear: both p=0.0004) and cyclin E: p=000003, p<0.000001, and weaker expression of p27: p=0.00003, p=0.0001 and cyclin D1: both p<0.000001; for sBBC some of these correlations were absent. Higher p27 score correlated with lower HER2 expression in sBBC: p=0.018, whereas higher HER2 expression was associated with higher p53: 0.024 and cyclin E: p=0.048 expression in all BBC and higher nuclear expression of cyclin B in sBBC: p=0.027. Higher Ki-67 expression was correlated with higher expression of p16 (cytoplasmic: p=0.000015, p=0.086, p=0.0002 and nuclear: p=0.000009, p=0.016, p=0.00003) in all subsets [all BBC, sBBC (non-significant for cytoplasmic score), mBBC, respectively], p21 (all BBC: p=0.05) and sBBC: p=0.017), p53 (all BBC: p=0.0003 and mBBC: p=0.0002), cyclin A: all p<0.000001, cyclin B (cytoplasmic: p<0.000001, p=0.004, p<0.000001, respectively and nuclear: p=0.0002, p=0.047, p=0.0026, respectively), cyclin D3 (all BBC: p=0.005 and mBBC: p=0.02) and cyclin E (all BBC: p<0.000001 and mBBC: p=0.000002), and lower expression of cyclin D1 (all BBC: p=0.046 and mBBC: p=0.035) and p27 (sBBC: p=0.048).

CONCLUSION

Compared to sBBC, mBBC are characterized by lower expression of p21 and higher cytoplasmic expression of cyclin B, suggesting its more aggressive behavior. Correlations between cell-cycle regulation proteins and markers of breast cancer phenotype parallel those reported for unilateral breast cancer.