Oncotype Dx recurrence score among BRCA1/2 germline mutation carriers with hormone receptors positive breast cancer

HR-positive/HER2-negative breast cancer arising in patients with or without BRCA2 mutation: different biological phenotype and similar prognosis

Background

BRCA2 plays a key role in homologous recombination. However, information regarding its mutations in Chinese patients with breast cancer remains limited.

Objectives

This study aimed to assess the clinicopathological characteristics of BRCA2 mutation breast cancer and explore the mutation's effect on hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer survival in China.

Design

This hospital-based cohort study prospectively included 629 women with breast cancer diagnosed from 2008 to 2023 at Zhejiang Cancer Hospital in China.

Methods

We compared the clinicopathological characteristics and metastatic patterns and analysed the invasive disease-free survival (iDFS), distant relapse-free survival (DRFS) and first-line progression-free survival (PFS1) of patients with HR-positive/HER2-negative breast cancer according to BRCA2 mutations.

Results

Among the 629 patients, 78 had BRCA2 mutations (12.4%) and 551 did not (87.6%). The mean age at diagnosis was lower in the BRCA2 mutation breast cancer group than in the non-mutation breast cancer group (38.91 versus 41.94 years, p = 0.016). BRCA2 mutation breast cancers were more likely to be lymph node-positive than non-mutation breast cancers (73.0% versus 56.6%, p = 0.037). The pathological grade was higher in 47.1% of BRCA2 mutation breast cancers than in 29.6% of non-mutation breast cancers (p = 0.014). The proportions of patients with BRCA2 mutations who developed contralateral breast cancer (19.2% versus 8.8%, p = 0.004), breast cancer in the family (53.8% versus 38.3%, p = 0.009) and ovarian cancer in the family (7.6% versus 2.4%, p = 0.022) were higher than those of patients without the mutation. The median follow-up time was 92.78 months. Multivariate analysis showed that BRCA2 mutation was not associated with poorer iDFS [hazard ratio = 0.9, 95% confidence interval (CI) = 0.64-1.27, p = 0.56] and poorer distant relapse-free survival (DRFS) (hazard ratio = 1.09, 95% CI = 0.61-1.93, p = 0.76). There was no significant difference between the two groups with regard to metastatic patterns in the advanced disease setting. In the first-line metastatic breast cancer setting, PFS1 expression was broadly similar between the two groups irrespective of chemotherapy or endocrine therapy.

Conclusion

HR-positive/HER2-negative breast cancer with BRCA2 mutations differs from those without mutations in clinical behaviour and reflects more aggressive tumour behaviour. Our results indicate that BRCA2 mutations have no significant effect on the survival of Chinese women with HR-positive/HER2-negative breast cancer.

ER-positive and BRCA2-mutated breast cancer: a literature review

BRCA2-mutated carriers have a high lifetime risk of breast cancer (BC), an early age of onset, and an increased risk of other cancers (including ovarian, pancreatic, and prostate cancer). Almost 70-80% of BRCA2-mutated BC are estrogen receptor (ER)-positive, which is a particular type of ER-positive BC that differs from sporadic ER-positive BC. This article reviews the clinicopathological features, treatment, and prognosis of ER-positive and BRCA2-mutated BC to provide a reference for clinical decision-making.

Estrogen receptor-positive breast cancer and adverse outcome in BRCA2 mutation carriers and young non-carrier patients

Estrogen receptor-positive (ER+) breast cancer generally confers a more favorable prognosis than ER-negative cancer, however, a different picture is emerging for BRCA2 mutation carriers and young patients. We used nationwide data from population-based registries to study prognostic effects in those two groups. Of all 2817 eligible women diagnosed with breast cancer in Iceland during 1980-2004, 85% had been tested for the Icelandic 999del5 BRCA2 (c.771_775delTCAAA) founder pathogenic variant. We compared breast cancer-specific survival, effects of ER status, other clinical parameters, and treatment, between three mutually exclusive groups: BRCA2-carriers, non-carriers diagnosed 40 years or younger, and older non-carriers. Prevalence of the BRCA2 mutation among tested patients <=40 years of age was 21.0%, but it was 5.4% among women diagnosed >40 years of age. For ER+ cancer, breast cancer-specific 15-year survival was 49.7%, 55.2%, and 74.7%, among BRCA2-carriers, young and older non-carriers, respectively, whereas for ER-negative cancer, survival was similar (64.0-69.3%) for all three groups. Neither BRCA2 carriers nor young non-carriers did tumor grade 3 predict worse survival than did tumor grade 1. The adverse outcome for the young cases cannot be explained by BRCA2 mutations, as carriers were excluded from the group. Those two clinically important patient groups need special attention with respect to treatment choices, in particular, if diagnosed with ER+ tumors. It is thus advisable to have knowledge of BRCA2 status when treatment decisions are made. Finally, it is important to understand the biological basis for the specific nature of ER+ tumors in young women and BRCA2 carriers.

Progress and prospects in research and clinical practice of hormone receptor-positive, HER-2-negative breast cancer with BRCA1/2 mutations

Breast cancer (BC) is a heterogeneous disease that is the most common cancer in women worldwide. However, precise subtyping and corresponding treatments have improved patient outcomes. Hormone receptor (HR)-positive, human epidermal growth factor receptor type 2 (HER2)-negative (HR+/HER2-) BC with BRCA1 and/or BRCA2 mutations (BRCA1/2m) is a unique BC subset with dual drivers: homologous recombination deficiency and hormone receptor signaling. Wild-type BRCA1/2 suppresses estrogen receptor-mediated signaling. Loss-of-function mutations in BRCA1/2 release estrogen receptor suppression, leading to reduced sensitivity to endocrine therapy. Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) exert antitumor effects against this subtype and can be used in combination with endocrine therapy. Although PARPis have been evaluated in metastatic triple-negative breast cancer, their efficacy against HR+/HER2- BC has not been clearly established. The present review summarizes recent advances and prospects in the progress of the HR+/HER2-/BRCA1/2m subgroup. As such, this article provides theoretical guidance for future research and promotes the use of PARPis for the treatment of HR+/HER2-/BRCA1/2m BC.

Efficacy of front-line treatment for hormone receptor-positive HER2-negative metastatic breast cancer with germline BRCA1/2 mutation

BACKGROUND

Efficacy of endocrine therapy in HR+/HER2- metastatic breast cancer could differ depending on the presence of BRCA1/2 germline mutation.

METHODS

The ESME metastatic breast cancer platform (NCT03275311) is a French real world database. Multivariable models including a time-varying approach and landmark analyses assessed the association between time-dependent gBRCA status (categorised as gBRCAm, gBRCAwt (wild type), and untested), overall survival (OS), and first-line progression-free survival (PFS1).

RESULTS

A total of 170 patients were gBRCAm carriers, 676 gBRCAwt, and 12,930 were untested at baseline. In the multivariable analysis, gBRCAm carriers overall had a lower OS compared to gBRCAwt (adjusted HR [95% CI] 1.26 [1.03-1.55]). gBRCAm patients treated with front-line endocrine therapy had lower adjusted OS (adjusted HR [95% CI] = 1.54 [1.03-2.32]) and PFS1 (adjusted HR [95% CI] 1.58 [1.17-2.12]) compared to gBRCAwt patients. However, for patients who received frontline chemotherapy, neither OS nor PFS1 differed between gBRCAm carriers and the other groups (HR versus gBRCAwt for OS: 1.12 [0.88-1.41], p = 0.350; PFS1: 1.09 [0.90-1.31], p = 0.379).

CONCLUSION

In this large cohort of HR+/HER2- MBC patients treated in a pre-CDK4/6 inhibitors era, gBRCAm status was associated with a lower OS and lower PFS following first-line endocrine therapy, but not following first-line chemotherapy.

Distinct breast cancer phenotypes in BRCA 1/2 carriers based on ER status

PURPOSE

BRCA1/2 genes are the two main genes associated with hereditary breast cancers (BC). In the present study, we explore clinical and molecular characteristics of BRCA-associated BC in relation to estrogen receptor (ER) status.

METHODS

Three BC databases (DB) were evaluated: (i) Hadassah oncogenetics (n = 4826); (ii) METABRIC (n = 1980), and (iii) Nick-Zainal (n = 560). We evaluated age at diagnosis in BRCA positive (BP) and BRCA negative (BN) patients, and tested for mutational signature differences in cohort iii. mRNA differential expression analysis (DEA) and pathway analysis were performed in cohort ii.

RESULTS

Age at diagnosis was lower in BP vs. BN tumors in all cohorts in the ER- group, and only in cohort i for the ER + group. Signature 3 was universal in BP BC, whereas several signatures were associated with ER status. Pathway analysis was performed between BP&BN, and was significant only in ER- tumors: the major activated pathways involved cancer-related processes and were highly significant. The most significant pathway was estrogen-mediated S-phase entry and the most activated upstream regulator was ERBB2.

CONCLUSION

Signature 3 was universal for all BP BC, while other signatures were associated with ER status. ER + BP& BN show similar genomic characteristics, ER- BP differed markedly from BN. This suggests that the initial carcinogenic process is universal for all BRCA carriers, but further insults lead to the development of two genomically distinct subtypes ER- and ER + . This may shed light on possible mechanisms involved in BP and carry preventive and therapeutic implications.

Prognostic and Predictive Biomarkers in Familial Breast Cancer

Large numbers of breast cancers arise within a familial context, either with known inherited germline mutations largely within DNA repair genes, or with a strong family history of breast and/or ovarian cancer, with unknown genetic underlying mechanisms. These cancers appear to be different to sporadic cases, with earlier age of onset, increased multifocality and with association with specific breast cancer histological and phenotypic subtypes. Furthermore, tumours showing homologous recombination deficiency, due to loss of BRCA1, BRCA2, PALB2 and CHEK2 function, have been shown to be especially sensitive to platinum-based chemotherapeutics and PARP inhibition. While there is extensive research and data accrued on risk stratification and genetic predisposition, there are few data pertaining to relevant prognostic and predictive biomarkers within this breast cancer subgroup. The following is a review of such biomarkers in male and female familial breast cancer, although the data for the former are particularly sparse.

Effectiveness of Secondary Risk-Reducing Strategies in Patients With Unilateral Breast Cancer With Pathogenic Variants of BRCA1 and BRCA2 Subjected to Breast-Conserving Surgery: Evidence-Based Simulation Study

BACKGROUND

Approximately 62% of patients with breast cancer with a pathogenic variant (BRCA1 or BRCA2) undergo primary breast-conserving therapy.

OBJECTIVE

The study aims to develop a personalized risk management decision support tool for carriers of a pathogenic variant (BRCA1 or BRCA2) who underwent breast-conserving therapy for unilateral early-stage breast cancer.

METHODS

We developed a Bayesian network model of a hypothetical cohort of carriers of BRCA1 or BRCA2 diagnosed with stage I/II unilateral breast cancer and treated with breast-conserving treatment who underwent subsequent second primary cancer risk-reducing strategies. Using event dependencies structured according to expert knowledge and conditional probabilities obtained from published evidence, we predicted the 40-year overall survival rate of different risk-reducing strategies for 144 cohorts of women defined by the type of pathogenic variants (BRCA1 or BRCA2), age at primary breast cancer diagnosis, breast cancer subtype, stage of primary breast cancer, and presence or absence of adjuvant chemotherapy.

RESULTS

Absence of adjuvant chemotherapy was the most powerful factor that was linked to a dramatic decline in survival. There was a negligible decline in the mortality in patients with triple-negative breast cancer, who received no chemotherapy and underwent any secondary risk-reducing strategy, compared with surveillance. The potential survival benefit from any risk-reducing strategy was more modest in patients with triple-negative breast cancer who received chemotherapy compared with patients with luminal breast cancer. However, most patients with triple-negative breast cancer in stage I benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy or just risk-reducing salpingo-oophorectomy. Most patients with luminal stage I/II unilateral breast cancer benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy. The impact of risk-reducing salpingo-oophorectomy in patients with luminal breast cancer in stage I/II increased with age. Most older patients with the BRCA1 and BRCA2 pathogenic variants in exons 12-24/25 with luminal breast cancer may gain a similar survival benefit from other risk-reducing strategies or surveillance.

CONCLUSIONS

Our study showed that it is mandatory to consider the complex interplay between the types of BRCA1 and BRCA2 pathogenic variants, age at primary breast cancer diagnosis, breast cancer subtype and stage, and received systemic treatment. As no prospective study results are available at the moment, our simulation model, which will integrate a decision support system in the near future, could facilitate the conversation between the health care provider and patient and help to weigh all the options for risk-reducing strategies leading to a more balanced decision.

Breast Cancer with Low Recurrence Score on Oncotype DX©: Interplay Between Early Recurrence, Lobular Histology and BRCA Mutation

INTRODUCTION

The 21-gene recurrence score assay Oncotype DX^© (ODX) has clear prognostic and predictive value regarding adjuvant chemotherapy. However, recent studies have shown the clinical distinctiveness of both BRCA1/2-driven early breast cancer (EBC) and invasive lobular (ILC) breast cancers. We evaluated the association between BRCA1/2-driven EBC/ILC and Oncotype DX failure despite a recurrence score ≤ 20.

METHODS

Here, we describe a small cohort of 16 patients from our center who, despite a low recurrence score (RS) ≤ 20, suffered from early disease recurrence. Clinical parameters of our cohort of patients were compared to a cohort from the general population of Clalit Health Service (CHS).

RESULTS

Median age at diagnosis in our cohort was significantly younger. BRCA mutational status was available in 14 patients in our cohort. A high percentage of these patients had BRCA1/2 mutations (35.7%), either germline (in 3) or somatic (in 2). Half of our cohort was diagnosed with lobular carcinoma (ILC) relative to 10-15% in the general population of BC (p = 0.02). The median time to recurrence was 44 months.

CONCLUSION

BRCA1/2 mutation and ILC are highly represented in this cohort. Although our cohort is small, these data may suggest that a RS ≤ 20 in these subgroups may not reflect a low risk of recurrence.

Clinical outcomes and Oncotype DX Breast Recurrence Score® in early-stage BRCA-associated hormone receptor-positive breast cancer

Background

BRCA‐associated breast cancers tend to have distinctive features compared to sporadic breast cancers; further characterization can aid in optimizing treatment.

Methods

The study evaluated a patient cohort with early‐stage estrogen receptor positive, HER2 negative invasive breast cancer who had Oncotype DX Breast Recurrence Score® analysis and genetic testing for hereditary breast and ovarian cancer syndrome. Data on patients and their breast cancers with outcomes were collected and analyzed.

Results

745 patients were included, of whom 33 had pathogenic BRCA mutations (8 BRCA1, 25 BRCA2). Patients with BRCA mutations were younger and received more adjuvant chemotherapy, but less endocrine therapy and radiation therapy. BRCA‐associated breast cancers had less progesterone receptor expression, higher nuclear grade, and higher Oncotype DX Breast Recurrence Scores® with median Recurrence Score® 29, compared to 16 in cancers without mutations (p < 0.0001). Breast cancer recurrence developed in 18% of patients with BRCA mutations and 9% of patient without mutations, although multivariate analysis of relapse‐free survival was not significant, HR 1.519 (95% confidence interval [CI] 0.64–3.58; p = 0.3401). After adjusting for Recurrence Score®, overall survival by BRCA status was improved HR 0.448 (95% CI 0.06–3.34; p = 0.4333).

Conclusions

BRCA‐associated early‐stage hormone receptor‐positive breast cancers have higher Oncotype DX Breast Recurrence Score® compared to those without mutations. BRCA status did not significantly impact relapse‐free survival and overall survival. Larger clinical trials are needed to further assess the findings, and if confirmed, could impact clinical management of BRCA‐associated breast cancers.

A Real-World Evidence Study of CDK4/6 Inhibitor Treatment Patterns and Outcomes in Metastatic Breast Cancer by Germline BRCA Mutation Status

Introduction

Limited data exist on real-world treatment patterns and the effectiveness of cyclin-dependent kinase (CDK) 4/6 inhibitors in germline BRCA (gBRCA)-mutated breast cancer.

Methods

Adults with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) metastatic breast cancer (mBC) treated with CDK4/6 inhibitor therapy between 2013 and 2018 were retrospectively selected from the Flatiron Health database. Patients with known gBRCA status were classified as mutated (gBRCAm) or wild type (gBRCAwt). Time-to-first subsequent therapy or death (TFST) and overall survival (OS) were calculated from the earliest line of therapy with a CDK4/6 inhibitor.

Results

Of 2968 patients with HR+/HER2− mBC receiving a CDK4/6 inhibitor, 859 (28.9%) had known gBRCA status, of whom 9.9% were gBRCAm and 90.1% gBRCAwt. Median (95% confidence interval [CI]) TFST was 10 (7–11) months in the gBRCAm group, 10 (9–11) months in the gBRCAwt group, and 11 (10–12) months in the combined gBRCAwt and unknown gBRCA group; median (95% CI) OS was 26 (21–not estimated), 37 (31–51), and 33 (31–35) months, respectively. Cox models indicated the gBRCAm group had shorter TFST (stratified hazard ratio [sHR] 1.24; 95% CI 0.96–1.59) and OS (sHR 1.50; 95% CI 1.06–2.14) than the gBRCAwt group. The gBRCAm group had shorter TFST (sHR 1.38; 95% CI 1.08–1.75) and OS (sHR 1.22; 95% CI 0.88–1.71) than the combined group.

Conclusion

The results of this real-world study suggest that treatment outcomes with CDK4/6 inhibitors may be worse in patients with gBRCAm mBC than in their counterparts with gBRCAwt and unknown gBRCA status, suggesting potential differences in tumor biology. This result highlights the unmet need in patients with gBRCAm requiring optimized treatment selection and sequencing. Future exploration in larger samples of patients who have had biomarker testing is warranted.

OncotypeDX© Recurrence Score in BRCA mutation carriers: a systematic review and meta-analysis

INTRODUCTION

There are limited data comparing the OncotypeDX© Recurrence Score (RS) among BRCA mutation carriers and patients with sporadic breast cancer.

AIM

To compare RS results among BRCA mutation carriers and patients with sporadic breast cancer in oestrogen receptor positive (ER+), human epidermal growth factor receptor-2 negative (HER2-) breast cancer.

METHODS

A systematic review was performed in accordance with PRISMA and MOOSE guidelines. Retrospective cohort studies comparing RS in BRCA mutation carriers and cases of sporadic cancer were included. Dichotomous variables were pooled as odds ratios (ORs) and associated 95% confidence intervals (CIs) using the Mantel-Haenszel method.

RESULTS

Five studies involving 4286 patients were included with a mean age of 60 years (range 22-85). Overall, 7.8% were BRCA mutation carriers (333/4286). The mean RS was 18.0 (range 0-71), and the mean RS in BRCA carriers was 25 (range 10-71) versus 18.4 in cases of sporadic disease (range 0-62). Patients with sporadic cancers were more likely to have RS < 18 (OR 0.27, 95% CI 0.14-0.51, P = 0.010). BRCA mutation carriers were more likely to have RS 18-30 (OR 1.74, 95% CI 1.28-2.37, P < 0.001) and RS > 30 (OR 3.71, 95% CI 2.55-5.40, P < 0.001).

CONCLUSION

There is an increased likelihood of high-risk RS among patients with known germline BRCA mutations when compared to patients developing sporadic ER+/HER2-early breast cancer. This study offers insight into genomic testing results within BRCA mutation carriers which may be useful in counselling patients with BRCA mutations in future practice.

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.

Predicted Chemotherapy Benefit for Breast Cancer Patients With Germline Pathogenic Variants in Cancer Susceptibility Genes

Breast cancer patients increasingly undergo genetic testing. To examine chemotherapy indications for germline pathogenic variant (PV) carriers, we linked results of germline testing to Georgia and California Surveillance, Epidemiology, and End Results registry records, including 21-gene recurrence score (RS) results, for breast cancer patients diagnosed in 2013-2017. All statistical tests were 2-sided. Patients (N=37 349) had RS results of whom 714 had BRCA1, BRCA2, CHEK2, ATM, PALB2, or Lynch syndrome (MLH1, MSH2, MSH6, PMS2) PVs. For women aged 50 years or older at breast cancer diagnosis, RS often exceeded the chemotherapy benefit threshold (≥26) with BRCA1 (71.7% vs 14.4% with none; P <.001), PALB2 (37.1%; P = .001), and BRCA2 (44.3%; P < .001) PVs. Results were similar for women diagnosed at younger than 50 years of age. PVs in BRCA1, but not BRCA2, PALB2, ATM, CHEK2, or Lynch syndrome genes, were associated with elevated RS on multivariable analysis (P < .001). Results may inform RS testing decisions in breast cancer patients with PVs.

Tumour profiling tests to guide adjuvant chemotherapy decisions in early breast cancer: a systematic review and economic analysis

BACKGROUND

Breast cancer and its treatment can have an impact on health-related quality of life and survival. Tumour profiling tests aim to identify whether or not women need chemotherapy owing to their risk of relapse.

OBJECTIVES

To conduct a systematic review of the effectiveness and cost-effectiveness of the tumour profiling tests oncotype DX^® (Genomic Health, Inc., Redwood City, CA, USA), MammaPrint^® (Agendia, Inc., Amsterdam, the Netherlands), Prosigna^® (NanoString Technologies, Inc., Seattle, WA, USA), EndoPredict^® (Myriad Genetics Ltd, London, UK) and immunohistochemistry 4 (IHC4). To develop a health economic model to assess the cost-effectiveness of these tests compared with clinical tools to guide the use of adjuvant chemotherapy in early-stage breast cancer from the perspective of the NHS and Personal Social Services.

DESIGN

A systematic review and health economic analysis were conducted.

REVIEW METHODS

The systematic review was partially an update of a 2013 review. Nine databases were searched in February 2017. The review included studies assessing clinical effectiveness in people with oestrogen receptor-positive, human epidermal growth factor receptor 2-negative, stage I or II cancer with zero to three positive lymph nodes. The economic analysis included a review of existing analyses and the development of a de novo model.

RESULTS

A total of 153 studies were identified. Only one completed randomised controlled trial (RCT) using a tumour profiling test in clinical practice was identified: Microarray In Node-negative Disease may Avoid ChemoTherapy (MINDACT) for MammaPrint. Other studies suggest that all the tests can provide information on the risk of relapse; however, results were more varied in lymph node-positive (LN+) patients than in lymph node-negative (LN0) patients. There is limited and varying evidence that oncotype DX and MammaPrint can predict benefit from chemotherapy. The net change in the percentage of patients with a chemotherapy recommendation or decision pre/post test ranged from an increase of 1% to a decrease of 23% among UK studies and a decrease of 0% to 64% across European studies. The health economic analysis suggests that the incremental cost-effectiveness ratios for the tests versus current practice are broadly favourable for the following scenarios: (1) oncotype DX, for the LN0 subgroup with a Nottingham Prognostic Index (NPI) of > 3.4 and the one to three positive lymph nodes (LN1-3) subgroup (if a predictive benefit is assumed); (2) IHC4 plus clinical factors (IHC4+C), for all patient subgroups; (3) Prosigna, for the LN0 subgroup with a NPI of > 3.4 and the LN1-3 subgroup; (4) EndoPredict Clinical, for the LN1-3 subgroup only; and (5) MammaPrint, for no subgroups.

LIMITATIONS

There was only one completed RCT using a tumour profiling test in clinical practice. Except for oncotype DX in the LN0 group with a NPI score of > 3.4 (clinical intermediate risk), evidence surrounding pre- and post-test chemotherapy probabilities is subject to considerable uncertainty. There is uncertainty regarding whether or not oncotype DX and MammaPrint are predictive of chemotherapy benefit. The MammaPrint analysis uses a different data source to the other four tests. The Translational substudy of the Arimidex, Tamoxifen, Alone or in Combination (TransATAC) study (used in the economic modelling) has a number of limitations.

CONCLUSIONS

The review suggests that all the tests can provide prognostic information on the risk of relapse; results were more varied in LN+ patients than in LN0 patients. There is limited and varying evidence that oncotype DX and MammaPrint are predictive of chemotherapy benefit. Health economic analyses indicate that some tests may have a favourable cost-effectiveness profile for certain patient subgroups; all estimates are subject to uncertainty. More evidence is needed on the prediction of chemotherapy benefit, long-term impacts and changes in UK pre-/post-chemotherapy decisions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017059561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

BRCA Mutation Association with Recurrence Score and Discordance in a Large Oncotype Database

BACKGROUND

The Oncotype DX Breast Cancer Assay is a 21-gene assay used to predict the likelihood of distant recurrence and the benefit of chemotherapy in patients with node-negative, tamoxifen-treated breast cancer. Prior studies demonstrated 7-19% discordance, or a difference between the recurrence score (RS) and tumor grade (TG) in breast cancer patients. BRCA mutated tumors (BRCA+) have been shown to be associated with higher RS as compared to BRCA-negative patients (BRCA-).

OBJECTIVES

We developed a large Oncotype RS database to determine if the BRCA mutation status is associated with discordance.

METHODS

We identified 723 patients (32 [4%] mutation-positive and 691 [96%] mutation-negative patients) with early-stage, hormone-positive breast cancer treated between 2006 and 2018, with tumor characteristics available for analysis. Discordance was defined as one- or two-step difference between RS (low, intermediate, high risk) and TG (well [WD], moderately [MD], and poorly [PD] differentiated). Mutation positive was defined as BRCA1 deleterious mutation, BRCA2 deleterious mutation, BRCA mutation of unknown type, BRCA variant of undetermined significance (VUS) or other mutation (classified as other VUS). Number (%) or median were used to describe patient characteristics between groups and were compared by the Kruskal-Wallis test at a significance level of 5%.

RESULTS

Among these patients, there were 32 (4% of total) who were identified as mutation-positive. Of those patients, 16% had a documented deleterious mutation in BRCA1, 22% in BRCA2, 6% had a BRCA mutation of unknown type (either 1 or 2), 25% were BRCA VUS, and 31% other VUS (most commonly CHEK2 and ATM). The median RS was 23.5 in patients with deleterious BRCA mutations (1, 2 or unknown) versus 16 in patients in the BRCA-negative database, which was statistically significant (p < 0.01). One- and two-step discordance was present in 46 and 8%, respectively, of patients with deleterious BRCA mutations versus 53 and 11%, respectively, in the BRCA-negative database.

CONCLUSIONS

Patients with deleterious BRCA mutations demonstrated no difference in rates of discordance as compared to BRCA-negative patients. We further demonstrated that patients with BRCA-positive tumors display higher RS than patients with BRCA-negative tumors.

Patterns of recurrence and metastasis in BRCA1/BRCA2-associated breast cancers

Background

Breast cancer subtypes are associated with distinct metastatic patterns. Whether germline BRCA1/BRCA2 mutation status is independently associated with central nervous system (CNS) relapse, controlling for tumor subtype, is unknown.

Methods

Patients who were treated at Dana‐Farber Cancer Institute and diagnosed with a first locoregional recurrence (LRR) or metastasis between 1981 and 2014 were identified using 2 institutional registries: 1) patients treated for recurrent breast cancer and 2) patients who underwent BRCA testing. The frequencies of LRR, sites of metastasis, and breast cancer‐specific survival from LRR or metastasis were calculated, and the factors associated with CNS recurrence were evaluated using multivariable logistic regression models.

Results

The final study cohort included 30 BRCA1 mutation carriers, 32 BRCA2 mutation carriers, and 270 noncarriers. Most BRCA1 carriers (73%) had triple‐negative breast cancer; whereas most BRCA2 carriers (72%) had hormone receptor‐positive tumors. BRCA1 carriers frequently experienced lung and distant lymph node metastasis, whereas BRCA2 carriers and noncarriers most often experienced bone metastasis. Although CNS disease occurred frequently in both BRCA1 and BRCA2 carriers (53% BRCA1, 50% BRCA2, 25% noncarriers; P < .001), only BRCA2 mutation (P = .006) was significantly associated with CNS metastasis in multivariable analysis controlling for tumor subtype. BRCA2 mutation (P = .01), triple‐negative subtype (P < .001), and the involvement of CNS (P < .001) and other non‐CNS distant sites (relative to locoregional recurrence or contralateral disease; P < .001) at presentation of recurrent breast cancer were associated with risk for mortality.

Conclusions

CNS involvement is frequent in women with germline BRCA1/BRCA2 mutations who have metastatic breast cancer. BRCA2 mutation carriers had a significantly higher frequency of CNS metastasis than noncarriers when controlling for breast cancer subtype.

Germline BRCA1 or BRCA2 alterations are associated with a high frequency (≥50%) of brain metastases in patients with locoregionally recurrent or metastatic breast cancer. In multivariable analysis, only BRCA2 mutation (P = .006) was significantly associated with central nervous system metastasis when controlling for breast cancer subtype.

An integrative view on breast cancer signature panels

Introduction: Breast cancer is heterogeneous with distinct clinical outcomes. Diverse types of markers are available on the market for breast cancer prognosis, diagnosis, and therapeutics, with distinct assay approaches. These, though they enlarge our selection pool for characterizing breast cancer patients and help improve the precision on the therapeutics, they can complicate our understanding and choice of marker panels. Areas covered: This review aims at classifying the commonly used marker panels according to their functionalities and detection approaches, comparing their advantages and disadvantages, and identifying their shared features to gain a comprehensive understanding of the diversified molecular profiles that drive breast cancer heterogeneity. Expert opinion: Our effort will contribute as a guidebook for clinicians on the use of breast cancer signature panels for disease management, and for researchers on the establishment of novel marker panels with improved precision and reduced complexity. We propose that collectively analyzing all available marker panels is equally important as investigating on entirely novel marker panels. Advances in technologies capturing signals from multiple levels are of practical importance in breaking through limitations on translating markers into clinical use.

Oestrogen receptor status and survival in women with BRCA2-associated breast cancer

BACKGROUND

To evaluate the predictors of mortality, including ER status, in women with a BRCA2 mutation and breast cancer.

METHODS

Eligible participants were identified from within two longitudinal cohorts. These patients were selected because they were diagnosed with breast cancer between 1975 and 2015 and carried a BRCA2 mutation. Data were abstracted from the medical record and pathology report. We analysed the effects of ER status and other variables on breast cancer specific survival using a Cox proportional hazards model.

RESULTS

Three hundred ninety women with breast cancer and a BRCA2 mutation were included in the analysis. The mean follow-up time was 12.3 years (range 1-39 years) and 89 subjects died (22.8%). In the multivariate analysis, women with ER-positive tumours were more likely to die than women with ER-negative tumours (HR 2.08, 95% CI 0.99-4.36, p = 0.05), and this was of borderline significance. For the 233 women with ER-positive tumours the 20-year survival rate was 62.2%, compared to 83.7% for 58 women with ER-negative tumours (p = 0.03).

CONCLUSIONS

The majority of women with a BRCA2 mutation present with ER-positive breast cancer, and for these women, prognosis may be worse than for BRCA2 carriers with ER-negative breast cancer.

Verification of a Western Nomogram for Predicting Oncotype DX™ Recurrence Scores in Korean Patients with Breast Cancer

A recent study conducted at the University of Tennessee Medical Center using a large dataset from the National Cancer Database (NCDB) reported the use of nomograms for predicting Oncotype DX™ (ODX) scores with clinicopathologic data. We reviewed the data of 218 patients who underwent the ODX test at a single institution in Korea to confirm that nomograms can accurately predict ODX score groups using our data, which differ from those of the NCDB in terms of ethnicity. The concordance index (c-index) of nomograms was much lower than that of the University of Tennessee Medical Center for high- and low-risk groups of commercial ODX and Trial Assigning Individualized Options for Treatment values. Although the nomogram for predicting ODX scores was based on a large dataset, it could not be generalized to patients in Asia. Further studies using large datasets of patients from different ethnicities should be performed to develop a nomogram applicable to patients worldwide.

PARP inhibitors in breast cancer: Bringing synthetic lethality to the bedside

Individuals with breast and ovarian cancer susceptibility gene 1 (BRCA1) or BRCA2 germline mutations have a significantly increased lifetime risk for breast and ovarian cancers. BRCA-mutant cancer cells have abnormal homologous recombination (HR) repair of DNA. In these tumors, the base excision repair (BER) pathway is important for cell survival. The poly(adenosine diphosphate-ribose) polymerase (PARP) enzymes play a key role in BER, and PARP inhibitors are effective in causing cell death in BRCA-mutant cells while sparing normal cells-a concept called synthetic lethality. PARP inhibitors are the first cancer therapeutics designed to exploit synthetic lethality. Recent clinical trials in BRCA-mutant, metastatic breast cancer demonstrated improved outcomes with single-agent PARP inhibitors (olaparib and talazoparib) over chemotherapy. However, resistance to PARP inhibitors remains a challenge. Primarily due to myelosuppression, the combination of PARP inhibitors with chemotherapy has been difficult. Novel combinations with chemotherapy, immunotherapy, and other targeted therapies are being pursued. In this review, the authors discuss current knowledge of PARP inhibitors in BRCA-mutant breast cancer and potential future directions for these agents. Cancer 2018;124:2498-506. © 2018 American Cancer Society.

Molecular Characterization and Mortality From Breast Cancer in Men

Purpose Limited data exist on the molecular biology, treatment, and outcomes of breast cancer in men, and much of our understanding in this area remains largely an extrapolation from data in women with breast cancer. Materials and Methods We studied men and women with hormone receptor-positive breast cancer and the 21-gene Breast Recurrence Score (RS) results. Differences in clinical characteristics and gene expression were determined, and distribution of RS results was correlated with 5-year breast cancer-specific survival (BCSS) and overall survival. Results There were 3,806 men and 571,115 women. Men were older than women (mean age, 64.2 v 59.1 years; P < .001). RS < 18 predominated in both genders, but RS ≥ 31 was more frequent in men (12.4% v 7.4%; P < .001), as were very low scores (RS < 11; 33.8% v 22.1%; P < .001). Mean gene expression was higher in men for the estrogen receptor (ER), proliferation, and invasion groups. ER was lowest and progesterone receptor was highest in women younger than 50 years of age, with a progressive increase in ER with age. Men younger than 50 years of age had slightly lower ER and progesterone receptor compared with older men. Survival data were available from SEER for 322 men and 55,842 women. Five-year BCSS was 99.0% (95% CI, 99.3% to 99.9%) and 95.9% (95% CI, 87.6% to 98.7%) for men with RS < 18 and RS 18-30, respectively, and for women, it was 99.5% (95% CI, 99.4% to 99.6%) and 98.6% (95% CI, 98.4% to 98.8%), respectively. RS ≥ 31 was associated with an 81.0% 5-year BCSS in men (95% CI, 53.3% to 93.2%) and 94.9% 5-year BCSS (95% CI, 93.9% to 95.7%) in women. Five-year BCSS and overall survival were lower in men than in women. Conclusion This study reveals some distinctive biologic features of breast cancer in men and an important prognostic role for RS testing in both men and women.

The 21-Gene Recurrence Score in Male Breast Cancer

BACKGROUND

Given the limited data, systemic treatment of male breast cancer has been extrapolated from female patients. The 21-gene recurrence score (RS) assay estimates the risk of distant recurrence and chemotherapy benefit in early-stage, ER+/HER2- female breast cancer. We assessed the association between RS and type of treatment in male breast cancer.

METHODS

We identified male patients with ER+/HER2- breast cancer and available RS results treated at our institution in 2006-2016. We collected data on clinicopathologic features, treatment, and outcome. The Institutional Review Board approved the study.

RESULTS

The study cohort consists of 38 male breast cancer patients with a median age of 70 years. Median tumor size was 1.6 cm, and 81.6% (31) were node-negative. RS was low (≤ 17) in 26 (68.4%) cases, intermediate (18-30) in 9 (23.7%) cases, and high (≥ 31) in 3 (7.9%) cases, comparable to that in female patients at our institution. All patients underwent total mastectomy, and one received radiotherapy. Thirty-four (89.5%) patients received adjuvant endocrine therapy, mostly tamoxifen (81.6%; 31). Five (13.2%) patients with intermediate or high RS were treated with adjuvant chemotherapy. No locoregional recurrence was observed, and one patient developed distant recurrence (median follow-up 34 months).

CONCLUSIONS

The RS distribution in male breast cancers was similar to that in females treated at our institution. With limited follow-up, patients with low RS were spared chemotherapy and did not develop recurrence. Our results suggest that the RS may have a clinical utility in male breast cancer patients.