Impact of Age at Primary Breast Cancer on Contralateral Breast Cancer Risk in BRCA1/2 Mutation Carriers

Can contralateral prophylactic mastectomy and oophorectomy increase survival in BRCA-related breast cancer? Results from the Italian MUTina study

INTRODUCTION

In the Emilia-Romagna region of Italy, a unique Hub and Spoke model was adopted to recognize BRCA-related breast cancer (BC) patients. Characteristics and outcomes of tumors identified by this model will be presented.

METHODS

This multicenter retrospective cohort study involved patients diagnosed with BRCA-related BC identified in the Emilia-Romagna region between January 2000 and December 2013. Seven provinces collected data on patient and tumor characteristics; clinical and gene testing information were also registered. Comparisons between BRCA1 and BRCA2 BC were performed. To balance different variants to identify significant predictors of survival, an inverse probability of treatment weighting (IPTW) analysis on Cox regression was conducted.

RESULTS

From 2000 to 2013, 284 BRCA-related BC were registered (171 BRCA1, 110 BRCA2, and 3 BRCA1 and BRCA2). BRCA1 were diagnosed at an earlier stage compared to BRCA2 (50.1 % vs 30 %, respectively, in stage I, P = 0.0015). BRCA2 patients underwent more up-front surgery (85 % vs. 74.9 %, P = 0.049) and less chemotherapy (69.1 % vs 88.9 %, P = 0.004) than BRCA1 patients. At 11.8 years median follow-up, BRCA1 patients developed more second contralateral BC (P = 0.09), while BRCA2 had more visceral relapses (P = 0.013). No differences in overall survival (OS) between BRCA1 and BRCA2 patients (P = 0.07) were found. An advantage in OS was independently seen for patients who underwent contralateral prophylactic mastectomy (P = 0.0001) and oophorectomy (P < 0.0001).

CONCLUSIONS

In conclusion, adopting a homogeneous regional framework provides important information about prevention and treatment strategies of BRCA-related BC and suggests using maximal surgery to improve OS.

Fear of cancer recurrence in breast cancer survivors carrying a BRCA1 or 2 genetic mutation : a cross-sectional study

BACKGROUND

Fear of cancer recurrence (FCR) affects virtually all patients who have been treated for cancer, to varying degrees. Breast cancer survivors who carry a BRCA1 or BRCA2 gene mutation are at high risk of cancer recurrence. No study has yet assessed FCR specifically in this population.

OBJECTIVES

This cross-sectional study, conducted in women who were treated for breast cancer and carrying a BRCA1/2 mutation, aimed to: (1) assess the mean level of FCR and estimate the proportion of patients with clinical levels of FCR; (2) examine the relationships between FCR and selected psychological variables (e.g., avoidance, intolerance to uncertainty) and quality of life; (3) explore whether FCR levels vary as a function of the past preventive treatment received; and (4) to assess the associations between FCR and the presence of decisional conflict or regret regarding the various preventive options.

METHOD

Participants were recruited through an e-mail sent to an oncogenetic network mailing list (Réseau ROSE). Participants were asked to complete a battery of questionnaires online assessing FCR and other psychological and quality of life variables.

RESULTS

A total of 89 women completed the survey. Most participants had undergone a preventive mastectomy (62.9%) and a preventive salpingo-oophorectomy (75.3%) at the time of the study. The mean Fear of Cancer Recurrence Inventory-severity score was 16.8, which exceeds the clinical cut-off score of 13, and 70.8% of the participants showed a clinical level of FCR. FCR was significantly associated with higher levels of anxiety and depression, and higher avoidance and intolerance of uncertainty, but not with quality of life. No significant difference was observed on the total FCR score between women who had received preventive surgery (mastectomy and/or salpingo-oophorectomy) and those considering it, and those not considering it. The association was significant between higher FRC scores and greater decisional conflicts and regrets about choosing to undergo preventive surgery.

CONCLUSION

These data suggest that FCR is a significant problem for breast cancer survivors carrying a BRCA1/2 genetic mutation, even after undergoing a prophylactic surgery. This highlights the importance of providing these women with specific psychological intervention focusing on FCR.

Impact of breast surgical procedure on survival in BRCA mutated patients with invasive breast cancer: Mastectomy versus conservative treatment

INTRODUCTION

Patients with BRCA1/2 mutations have a higher risk of developing breast cancer compared to the wild-type population. For patients with a BRCA mutation, there are no specific recommendations for surgical management. The aim of this study was therefore to retrospectively investigate overall survival (OS) and recurrence-free survival (RFS) of BRCA mutated patients with localized invasive breast cancer, by comparing conservative surgery versus mastectomy.

METHODS

This study was based on data from the Côte d'Or breast and gynecological cancer registry. Data from patients with a constitutional BRCA1/2 mutation who presented with invasive breast cancer were collected retrospectively from 1998 to 2018. The Kaplan-Meier method was used to describe RFS and OS.

RESULTS

A total of 104 patients were included in the analysis, of whom 69 had conservative surgery and 35 underwent mastectomy. Regarding survival, there was no significant difference in OS (HR =1.49; 95 % confidence interval (CI) [0.76-2.93], p = 0.25). Similarly, there was no significant difference in RFS (HR =1.40; 95 % CI [0.81-2.40], p = 0.22), survival without homolateral recurrence (HR =0.88; 95 % CI [0.30-2.61], p = 0.89), without contralateral recurrence (HR =1.50; 95 % CI [0.55-4.09], p = 0.42), or without distant metastatic recurrence (HR =1.42, 95 % CI [0.69-2.90], p = 0.33).

CONCLUSION

In invasive breast cancer in a patient with a germline BRCA1/2 mutation, conservative surgery, when possible, appears to be a feasible option over total mastectomy, with no difference in overall survival. However, the patient should be informed of the aggressive nature of recurrence in this population requiring chemotherapy in most cases.

Germline Testing in Patients With Breast Cancer: ASCO-Society of Surgical Oncology Guideline

PURPOSE

To develop recommendations for germline mutation testing for patients with breast cancer.

METHODS

An ASCO-Society of Surgical Oncology (SSO) panel convened to develop recommendations based on a systematic review and formal consensus process.

RESULTS

Forty-seven articles met eligibility criteria for the germline mutation testing recommendations; 18 for the genetic counseling recommendations.

RECOMMENDATIONS

BRCA1/2 mutation testing should be offered to all newly diagnosed patients with breast cancer ≤65 years and select patients >65 years based on personal history, family history, ancestry, or eligibility for poly(ADP-ribose) polymerase (PARP) inhibitor therapy. All patients with recurrent breast cancer who are candidates for PARP inhibitor therapy should be offered BRCA1/2 testing, regardless of family history. BRCA1/2 testing should be offered to women who develop a second primary cancer in the ipsilateral or contralateral breast. For patients with prior history of breast cancer and without active disease, testing should be offered to patients diagnosed ≤65 years and selectively in patients diagnosed after 65 years, if it will inform personal and family risk. Testing for high-penetrance cancer susceptibility genes beyond BRCA1/2 should be offered to those with supportive family histories; testing for moderate-penetrance genes may be offered if necessary to inform personal and family cancer risk. Patients should be provided enough pretest information for informed consent; those with pathogenic variants should receive individualized post-test counseling. Variants of uncertain significance should not impact management, and patients with such variants should be followed for reclassification. Referral to providers experienced in clinical cancer genetics may help facilitate patient selection and interpretation of expanded testing, and provide counseling of individuals without pathogenic germline variants but with significant family history.Additional information is available at www.asco.org/breast-cancer-guidelines.

Universal Germline-Genetic Testing for Breast Cancer: Implementation in a Rural Practice and Impact on Shared Decision-Making

BACKGROUND

Whereas the National Comprehensive Cancer Network (NCCN) criteria restrict germline-genetic testing (GGT) to a subset of breast cancer (BC) patients, the American Society of Breast Surgeons recommends universal GGT. Although the yield of pathogenic germline variants (PGV) in unselected BC patients has been studied, the practicality and utility of incorporating universal GGT into routine cancer care in community and rural settings is understudied. This study reports real-world implementation of universal GGT for patients with breast cancer and genetics-informed, treatment decision-making in a rural, community practice with limited resources.

METHODS

From 2019 to 2022, all patients with breast cancer at a small, rural hospital were offered GGT, using a genetics-extender model. Statistical analyses included Fisher's exact test, t-tests, and calculation of odds ratios. Significance was set at p < 0.05.

RESULTS

Of 210 patients with breast cancer who were offered GGT, 192 (91.4%) underwent testing with 104 (54.2%) in-criteria (IC) and 88 (45.8%) out-of-criteria (OOC) with NCCN guidelines. Pathogenic germline variants were identified in 25 patients (13.0%), with PGV frequencies of 15 of 104 (14.4%) in IC and ten of 88 (11.4%) in OOC patients (p = 0.495). GGT informed treatment for 129 of 185 (69.7%) patients.

CONCLUSIONS

Universal GGT was successfully implemented in a rural, community practice with > 90% uptake. Treatment was enhanced or de-escalated in those with and without clinically actionable PGVs, respectively. Universal GGT for patients with breast cancer is feasible within rural populations, enabling optimization of clinical care to patients' genetic profile, and may reduce unnecessary healthcare, resource utilization.

Contralateral breast cancer risk in patients with breast cancer and a germline-BRCA1/2 pathogenic variant undergoing radiation

BACKGROUND

Radiation-induced secondary breast cancer (BC) may be a concern after radiation therapy (RT) for primary breast cancer (PBC), especially in young patients with germline (g)BRCA-associated BC who already have high contralateral BC (CBC) risk and potentially increased genetic susceptibility to radiation. We sought to investigate whether adjuvant RT for PBC increases the risk of CBC in patients with gBRCA1/2-associated BC.

METHODS

The gBRCA1/2 pathogenic variant carriers diagnosed with PBC were selected from the prospective International BRCA1/2 Carrier Cohort Study. We used multivariable Cox proportional hazards models to investigate the association between RT (yes vs no) and CBC risk. We further stratified for BRCA status and age at PBC diagnosis (<40 and >40 years). Statistical significance tests were 2-sided.

RESULTS

Of 3602 eligible patients, 2297 (64%) received adjuvant RT. Median follow-up was 9.6 years. The RT group had more patients with stage III PBC than the non-RT group (15% vs 3%, P < .001), received chemotherapy more often (81% vs 70%, P < .001), and received endocrine therapy more often (50% vs 35%, P < .001). The RT group had an increased CBC risk compared with the non-RT group (adjusted hazard ratio [HR] = 1.44; 95% confidence interval [CI] = 1.12 to 1.86). Statistical significance was observed in gBRCA2 (HR = 1.77; 95% CI = 1.13 to 2.77) but not in gBRCA1 pathogenic variant carriers (HR = 1.29; 95% CI = 0.93 to 1.77; P = .39 for interaction). In the combined gBRCA1/2 group, patients irradiated when they were younger than or older than 40 years of age at PBC diagnosis showed similar risks (HR = 1.38; 95% CI = 0.93 to 2.04 and HR = 1.56; 95% CI = 1.11 to 2.19, respectively).

CONCLUSIONS

RT regimens minimizing contralateral breast dose should be considered in gBRCA1/2 pathogenic variant carriers.

Comparison of Survival Outcomes in Young Patients With Breast Cancer Receiving Contralateral Prophylactic Mastectomy Versus Unilateral Mastectomy

BACKGROUND

Contralateral prophylactic mastectomy (CPM) has been performed for several decades in patients with unilateral breast cancer (BC). However, the survival benefits of CPM are controversial, particularly in young women.

MATERIALS AND METHOD

In this retrospective study, the clinical total of 69,000 young female patients (age ≤ 40 years) who were diagnosed to have unilateral BC and underwent unilateral mastectomy (UM) or CPM between January 1, 2000 and December 31, 2019 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed to minimize selection bias and overcome differences in tumor characteristics between the CPM and UM groups. Overall survival (OS) and BC-specific survival (BCSS) were assessed using Kaplan-Meier curves and compared across groups using log-rank test. Multivariable Cox proportional hazards regression analysis was performed to estimate hazard ratios (HRs).

RESULTS

A total of 36,528 patients (21,600 and 14,928 patients in the UM and CPM groups, respectively) were included in follow study. The CPM group showed a higher 5-year OS rate (82.1% vs. 75.8%) and a higher 5-year BCSS rate (83.5% vs. 77.7%) than the UM group. Multivariate Cox analysis after PSM (n = 13,089) showed that CPM significantly decreased 25% risk of all-cause mortality (OS, HR: 0.75, 95% confidence interval [CI]: 0.70-0.80; P < .001) and 25% risk of BC-specific mortality (BCSS, HR: 0.75, 95% CI: 0.70-0.80; P < .001) in young BC patients as compared to UM.

CONCLUSION

This study suggests that CPM improved OS and BCSS benefits in young BC patients as compared to UM. Randomized clinical trials with a larger sample size are required in the future to confirm these results.

Association of common BRCA1 variants with predisposition to breast tumors in Pakistan

BRCA1 variants are extensively associated with increased risk of breast cancer. Early detection and screening of variants is still rare in developing countries. Here, we investigated six BRCA1 variants in 300 subjects from Pakistani population using tetra amplification-refractory mutation system (T-ARMS) PCR. Our results indicate significant association of BRCA1 variants rs8176237 (AA; OR 8.2, 95% CI 3.02-22.64, p < 0.0001), rs1060915 (CC; OR 4.29, 95% CI 1.94-9.48, p = 0.0003), and rs799912 (TT; OR 3.16, 95% CI 1.44-6.94, p = 0.004) with up to 8-fold increased odds of breast cancer under recessive model. Furthermore, BRCA1 haplotypes AGCACG and AGCCCT were associated with up to 18% breast cancer cases (p < 0.05). Additionally, we found association of these variants with up to 11-fold increased odds of benign breast tumors. Linkage disequilibrium (LD) block-wise analysis revealed haplotypes GCAC and ATAC were associated with significantly increased risk. To our knowledge, this is the first study that identifies the association of these BRCA1 variants with breast tumors in Pakistani population. In conclusion, BRCA1 variants investigated in the present study are associated with high odds of benign- and malignant breast tumors. Studies with bigger sample size may help early detection and screening to reduce the odds of breast cancer.

An overview of the research progress of BRCA gene mutations in breast cancer

The breast cancer susceptibility gene (BRCA) is an important tumor suppressor gene, including BRCA1 and BRCA2, a biomarker that assesses the risk of breast cancer and influences a patient's individualized treatment options. BRCA1/2 mutation (BRCAm) increases the risk of breast cancer. However, breast-conserving surgery is still an option for BRCAm, and prophylactic mastectomy and nipple-sparing mastectomy may also reduce the risk of breast cancer. BRCAm is sensitive to Poly (ADP-ribose) polymerase inhibitor (PARPi) therapy due to specific types of DNA repair defects, and its combination with other DNA damage pathway inhibitors and endocrine therapy and immunotherapy are also used for the treatment of BRCAm breast cancer. The current treatment and research progress of BRCA1/2 mutant breast cancer in this review provides a basis for the individualized treatment of patients with this type of breast cancer.

The impact of coding germline variants on contralateral breast cancer risk and survival

Evidence linking coding germline variants in breast cancer (BC)-susceptibility genes other than BRCA1, BRCA2, and CHEK2 with contralateral breast cancer (CBC) risk and breast cancer-specific survival (BCSS) is scarce. The aim of this study was to assess the association of protein-truncating variants (PTVs) and rare missense variants (MSVs) in nine known (ATM, BARD1, BRCA1, BRCA2, CHEK2, PALB2, RAD51C, RAD51D, and TP53) and 25 suspected BC-susceptibility genes with CBC risk and BCSS. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox regression models. Analyses included 34,401 women of European ancestry diagnosed with BC, including 676 CBCs and 3,449 BC deaths; the median follow-up was 10.9 years. Subtype analyses were based on estrogen receptor (ER) status of the first BC. Combined PTVs and pathogenic/likely pathogenic MSVs in BRCA1, BRCA2, and TP53 and PTVs in CHEK2 and PALB2 were associated with increased CBC risk [HRs (95% CIs): 2.88 (1.70-4.87), 2.31 (1.39-3.85), 8.29 (2.53-27.21), 2.25 (1.55-3.27), and 2.67 (1.33-5.35), respectively]. The strongest evidence of association with BCSS was for PTVs and pathogenic/likely pathogenic MSVs in BRCA2 (ER-positive BC) and TP53 and PTVs in CHEK2 [HRs (95% CIs): 1.53 (1.13-2.07), 2.08 (0.95-4.57), and 1.39 (1.13-1.72), respectively, after adjusting for tumor characteristics and treatment]. HRs were essentially unchanged when censoring for CBC, suggesting that these associations are not completely explained by increased CBC risk, tumor characteristics, or treatment. There was limited evidence of associations of PTVs and/or rare MSVs with CBC risk or BCSS for the 25 suspected BC genes. The CBC findings are relevant to treatment decisions, follow-up, and screening after BC diagnosis.

EBCC-13 manifesto: Balancing pros and cons for contralateral prophylactic mastectomy

After a diagnosis of unilateral breast cancer, increasing numbers of patients are requesting contralateral prophylactic mastectomy (CPM), the surgical removal of the healthy breast after diagnosis of unilateral breast cancer. It is important for the community of breast cancer specialists to provide meaningful guidance to women considering CPM. This manifesto discusses the issues and challenges of CPM and provides recommendations to improve oncological, surgical, physical and psychological outcomes for women presenting with unilateral breast cancer: (1) Communicate best available risks in manageable timeframes to prioritise actions; better risk stratification and implementation of risk-assessment tools combining family history, genetic and genomic information, and treatment and prognosis of the first breast cancer are required; (2) Reserve CPM for specific situations; in women not at high risk of contralateral breast cancer (CBC), ipsilateral breast-conserving surgery is the recommended option; (3) Encourage patients at low or intermediate risk of CBC to delay decisions on CPM until treatment for the primary cancer is complete, to focus on treating the existing disease first; (4) Provide patients with personalised information about the risk:benefit balance of CPM in manageable timeframes; (5) Ensure patients have an informed understanding of the competing risks for CBC and that there is a realistic plan for the patient; (6) Ensure patients understand the short- and long-term physical effects of CPM; (7) In patients considering CPM, offer psychological and surgical counselling before surgery; anxiety alone is not an indication for CPM; (8) Eliminate inequality between countries in reimbursement strategies; CPM should be reimbursed if it is considered a reasonable option resulting from multidisciplinary tumour board assessment; (9) Treat breast cancer patients at specialist breast units providing the entire patient-centred pathway.

BRCA-CRisk: A Contralateral Breast Cancer Risk Prediction Model for BRCA Carriers

PURPOSE

The absolute cumulative risk of contralateral breast cancer (CBC) for patients with BRCA1/2 variants is unknown. The purpose of this study was to develop a CBC risk prediction model for assessing CBC risk for BRCA1/2 carriers.

METHODS

The primary cohort of 491 patients with BRCA1/2 variants was derived from a large series of unselected patients with breast cancer. A nomogram was established on the basis of the results of a multivariate Cox regression analysis from this cohort. This model, named BRCA-CRisk, was further validated by an independent cohort of 205 patients with BRCA1/2 variants. Discrimination and calibration of the model were assessed.

RESULTS

In the primary cohort of 491 patients, 66 developed contralateral breast cancer after a median follow-up of 7.0 years. Four variables were significantly associated with risk of CBC and were incorporated in the establishment of the BRCA-CRisk prediction model: younger age at first breast cancer (with continuous variable, P = .002), positive first-degree family history of breast and/or ovarian cancer (hazard ratio [HR], 1.89; 95% CI, 1.16 to 3.08; P = .011), variant located near the 3' region of BRCA (HR, 2.01; 95% CI, 1.23 to 3.30; P = .006), and endocrine therapy (HR, 0.54; 95% CI, 0.33 to 0.88; P = .013). The area under the time-dependent curves for the 5- and 10-year cumulative risks of CBC were 0.775 and 0.702, respectively. The model was well validated in the independent cohort of 205 BRCA1/2 carriers, with area under the curves of 0.750 and 0.691 for 5 and 10 years, respectively.

CONCLUSION

BRCA-CRisk model provides a useful tool for assessing the absolute cumulative risk of CBC for BRCA1/2 carriers and may help carriers and clinicians optimally select risk-reducing strategies on the basis of individual CBC risk.

Psychological factors and the uptake of preventative measures in BRCA1/2 pathogenic variant carriers: results of a prospective cohort study

BACKGROUND

Women carrying BRCA1/2 pathogenic variants are exposed to elevated risks of developing breast cancer (BC) and are faced by a complex decision-making process on preventative measures, i.e., risk-reducing mastectomy (RRM), and intensified breast surveillance (IBS). In this prospective cohort study we investigated the effect of anxiety, personality factors and coping styles on the decision-making process on risk management options in women with pathogenic variants in BRCA1/2.

METHODS

Breast cancer unaffected and affected women with a pathogenic variant in the BRCA1 or BRCA2 gene were psychologically evaluated immediately before (T0), 6 to 8 weeks (T1) and 6 to 8 months (T2) after the disclosure of their genetic test results. Uptake of RRM and IBS was assessed at T2. Psychological data were gathered using questionnaires on risk perception, personality factors, coping styles, decisional conflict, depression and anxiety, including the Hospital Anxiety and Depression Scale (HADS). We performed tests on statistical significance and fitted a logistic regression based on significance level.

RESULTS

A total of 98 women were included in the analysis. Baseline anxiety levels in women opting for RRM were high but decreased over time, while they increased in women opting for intensified breast surveillance (IBS). Elevated levels of anxiety after genetic test result disclosure (T1) were associated with the decision to undergo RRM (p < 0.01; OR = 1.2, 95% CI = 1.05-1.42), while personal BC history and personality factors seemed to be less relevant.

CONCLUSIONS

Considering psychosocial factors influencing the decision-making process of women with pathogenic variants in BRCA1/2 may help improving their genetic and psychological counselling. When opting for IBS they may profit from additional medical and psychological counselling.

TRIAL REGISTRATION

Retrospectively registered at the German Clinical Trials Register under DRKS00027566 on January 13, 2022.

Prevalent versus incident breast cancers: benefits of clinical and radiological monitoring in women with pathogenic BRCA1/2 variants

Women with pathogenic germline BRCA1 or BRCA2 variants have a higher risk of breast cancer than in the general population. International guidelines recommend specific clinical and radiological breast follow-up. This specific breast screening program has already been shown to be of clinical benefit, but no information is available concerning the use of prognostic factors or specific survival to guide follow-up decisions. We evaluated "high-risk" screening in a retrospective single-center study of 520 women carrying pathogenic germline variants of the BRCA1 or BRCA2 gene treated for breast cancer between January 2000 and December 2016. We compared two groups of women: the incidental breast cancer group (IBCG) were followed before breast cancer diagnosis (N = 103), whereas the prevalent breast cancer group (PBCG) (N = 417) had no specific follow-up for high risk before breast cancer diagnosis. Breast cancers were diagnosed at an earlier stage in the IBCG than in the PBCG: T0 in 64% versus 19% of tumors, (p < 0.00001), and N0 in 90% vs. 75% (p < 0.00001), respectively. Treatment differed significantly between the 2 groups: less neoadjuvant chemotherapy (7.1% vs. 28.5%, p < 0.00001), adjuvant chemotherapy (47.7% vs. 61.9%, p = 0.004) and more mastectomies (60% vs. 42% p < 0.0001) in the IBCG vs PBCG groups respectively. Overall and breast cancer-specific mortality were similar between the two groups. However, the patients in the IBCG had a significantly longer metastasis-free survival than those in the PBCG, at three years (96.9% [95% CI 93.5-100] vs. 92.30% [95% CI 89.8-94.9]; p = 0.02), suggesting a possible long-term survival advantage.

Ways to improve breast cancer patients' management and clinical outcome: The 2020 Assisi Think Tank Meeting

We report on the third Assisi Think Tank Meeting (ATTM) on breast cancer, a brainstorming project which involved European radiation and clinical oncologists who were dedicated to breast cancer research and treatment. Held on February 2020, the ATTM aimed at identifying key clinical questions in current clinical practice and "grey" areas requiring research to improve management and outcomes. Before the meeting, three key topics were selected: 1) managing patients with frailty due to either age and/or multi-morbidity; 2) stereotactic radiation therapy and systemic therapy in the management of oligometastatic disease; 3) contralateral breast tumour prevention in BCRA-mutated patients. Clinical practice in these areas was investigated by means of an online questionnaire. In the lapse period between the survey and the meeting, the working groups reviewed data, on-going studies and the clinical challenges which were then discussed in-depth and subjected to intense brainstorming during the meeting; research protocols were also proposed. Methodology, outcome of discussions, conclusions and study proposals are summarized in the present paper. In conclusion, this report presents an in-depth analysis of the state of the art, grey areas and controversies in breast cancer radiation therapy and discusses how to confront them in the absence of evidence-based data to guide clinical decision-making.

Association Between Genetic Testing for Hereditary Breast Cancer and Contralateral Prophylactic Mastectomy Among Multiethnic Women Diagnosed With Early-Stage Breast Cancer

PURPOSE

Increasing usage of multigene panel testing has identified more patients with pathogenic or likely pathogenic (P or LP) variants in low-moderate penetrance genes or variants of uncertain significance (VUS). Our study evaluates the association between genetic test results and contralateral prophylactic mastectomy (CPM) among patients with breast cancer.

METHODS

We conducted a retrospective cohort study among women diagnosed with unilateral stage 0-III breast cancer between 2013 and 2020 who underwent genetic testing. We examined whether genetic test results were associated with CPM using multivariable logistic regression models.

RESULTS

Among 707 racially or ethnically diverse women, most had benign or likely benign (B or LB) variants, whereas 12.5% had P or LP and 17.9% had VUS. Racial or ethnic minorities were twice as likely to receive VUS. Patients with P or LP variants had higher CPM rates than VUS or B or LB (64.8% v 25.8% v 25.9%), and highest among women with P or LP variants in high-penetrance genes (74.6%). On multivariable analysis, P or LP compared with B or LB variants were significantly associated with CPM (odds ratio = 4.24; 95% CI, 2.48 to 7.26).

CONCLUSION

Women with P or LP variants on genetic testing were over four times more likely to undergo CPM than B or LB. Those with VUS had similar CPM rates as B or LB. Our findings suggest appropriate genetic counseling and communication of cancer risk to multiethnic breast cancer survivors.

Impact of BRCA mutation on the survival and risk of contralateral breast cancer in Asian breast cancer patients

PURPOSE

Breast cancer is increasing around the globe, including Asia. We aimed to examine the survival and risk of contralateral breast cancer (CBC) in Asian breast cancer patients with BRCA mutations.

METHODS

A total of 128 breast cancer patients with germline BRCA mutations and 4,754 control breast cancer patients were enrolled. Data on clinical-pathologic characteristics, survival, and CBC were collected from the medical record. The rates of survival and CBC were estimated by Kaplan-Meier method.

RESULTS

The mean age of onset in BRCA mutation carriers was significantly younger than control patients (BRCA vs. Non-BRCA: 43.9 vs. 53.2 years old). BRCA mutation carriers had a higher proportion of triple-negative breast cancer (TNBC) (52%) than control patients (12%, p < 0.001). The risk of CBC was significantly higher in BRCA mutation patients than in control cases (hazard ratio (HR) = 3.95, 95% CI 2.71-5.75); when stratified by genotype, the HRs (95%CI) were 4.84 (3.00-7.82) for BRCA1 and 3.13 (1.78-5.49) for BRCA2 carriers, respectively. Moreover, BRCA1 mutation patients with triple-negative breast cancer (TNBC) as their first breast cancer had the highest risk of CBC (HR = 5.55, 95% CI 3.29-9.34). However, we did not observe any differences in relapse-free survival and overall survival between mutation carriers and control patients.

CONCLUSION

Our study suggest that BRCA patients had a significantly higher risk of developing CBC, particularly for BRCA1 mutation carriers with TNBC as the first breast cancer.

Effects of chemotherapy on contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers: A nationwide cohort study

Aim

BRCA1/2 mutation carriers with primary breast cancer (PBC) are at high risk of contralateral breast cancer (CBC). In a nationwide cohort, we investigated the effects of chemotherapeutic agents given for PBC on CBC risk separately in BRCA1 and BRCA2 mutation carriers.

Patients and methods

BRCA1 or BRCA2 mutation carriers with an invasive PBC diagnosis from 1990 to 2017 were selected from a Dutch cohort. We estimated cumulative CBC incidence using competing risks analysis. Hazard ratios (HR) for the effect of neo-adjuvant or adjuvant chemotherapy and different chemotherapeutic agents on CBC risk were estimated using Cox regression.

Results

We included 1090 BRCA1 and 568 BRCA2 mutation carriers; median follow-up was 8.9 and 8.4 years, respectively. Ten-year cumulative CBC incidence for treatment with and without chemotherapy was 6.7% [95%CI: 5.1–8.6] and 16.7% [95%CI: 10.8–23.7] in BRCA1 and 4.8% [95%CI: 2.7–7.8] and 16.0% [95%CI: 9.3–24.4] in BRCA2 mutation carriers, respectively. Chemotherapy was associated with reduced CBC risk in BRCA1 (multivariable HR: 0.46, 95%CI: 0.29–0.74); a similar trend was observed in BRCA2 mutation carriers (HR: 0.63, 95%CI: 0.29–1.39). In BRCA1, risk reduction was most pronounced in the first 5 years (HR: 0.32, 95%CI: 0.17–0.61). Anthracyclines and the combination of anthracyclines with taxanes were associated with substantial CBC risk reduction in BRCA1 carriers (HR: 0.34, 95%CI: 0.17–0.68 and HR: 0.22, 95%CI: 0.08–0.62, respectively).

Conclusion

Risk-reducing effects of chemotherapy are substantial for at least 5 years and may be used in personalised CBC risk prediction in any case for BRCA1 mutation carriers.

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Contralateral breast cancer (CBC) risk is high in BRCA1/2 mutation carriers.

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Chemotherapy for primary breast cancer results in decreased CBC risk in BRCA1.

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Anthracyclines with/without taxanes show the largest CBC risk reduction in BRCA1.

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For BRCA2 similar trends are observed as in BRCA1 mutation carriers.

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Chemotherapy must be considered in personalised CBC risk models.

The risk of contralateral breast cancer: a SEER-based analysis

BACKGROUND

We sought to estimate the annual risk and 25-year cumulative risk of contralateral breast cancer among women with stage 0-III unilateral breast cancer.

METHODS

We identified 812,851 women with unilateral breast cancer diagnosed between 1990 and 2015 in the SEER database and followed them for contralateral breast cancer for up to 25 years. Women with a known bilateral mastectomy were excluded. We calculated the annual risk of contralateral breast cancer by age at diagnosis, by time since diagnosis and by current age. We compared risks by ductal carcinoma in situ (DCIS) versus invasive disease, by race and by oestrogen receptor (ER) status of the first cancer.

RESULTS

There were 25,958 cases of contralateral invasive breast cancer diagnosed (3.2% of all patients). The annual risk of contralateral breast cancer over the 25-year follow-up period was 0.37% and the 25-year actuarial risk of contralateral invasive breast cancer was 9.9%. The annual risk varied to a small degree by age of diagnosis, by time elapsed since diagnosis and by current age. The 25-year actuarial risk was similar for DCIS and invasive breast cancer patients (10.1 versus 9.9%). The 25-year actuarial risk was higher for black women (12.7%) than for white women (9.7%) and was lower for women with ER-positive breast cancer (9.5%) than for women with ER-negative breast cancer (11.2%).

CONCLUSIONS

Women with unilateral breast cancer experience an annual risk of contralateral breast cancer ~0.4% per year, which persists over the 25-year follow-up period.

Differences in Ovarian and Other Cancers Risks by Population and BRCA Mutation Location

Hereditary breast and ovarian cancer is caused by a germline mutation in BRCA1 or BRCA2 genes. The frequency of germline BRCA1/2 gene mutation carriers and the ratio of germline BRCA1 to BRCA2 mutations in BRCA-related cancer patients vary depending on the population. Genotype and phenotype correlations have been reported in BRCA mutant families, however, the correlations are rarely used for individual risk assessment and management. BRCA genetic testing has become a companion diagnostic for PARP inhibitors, and the number of families with germline BRCA mutation identified is growing rapidly. Therefore, it is expected that analysis of the risk of developing cancer will be possible in a large number of BRCA mutant carriers, and there is a possibility that personal and precision medicine for the carriers with specific common founder mutations will be realized. In this review, we investigated the association of ovarian cancer risk and BRCA mutation location, and differences of other BRCA-related cancer risks by BRCA1/2 mutation, and furthermore, we discussed the difference in the prevalence of germline BRCA mutation in ovarian cancer patients. As a result, although there are various discussions, there appear to be differences in ovarian cancer risk by population and BRCA mutation location. If it becomes possible to estimate the risk of developing BRCA-related cancer for each BRCA mutation type, the age at risk-reducing salpingo-oophorectomy can be determined individually. The decision would bring great benefits to young women with germline BRCA mutations.

Risk-Reducing Mastectomy and Reconstruction Following Prophylactic Breast Irradiation: Hope Sustained

Simple Summary

In this study we report the outcome of salvage mastectomy and reconstruction in 11 BRCA mutation carrier patients that participated in a clinical trial of prophylactic contralateral breast irradiation and suffered reoccurrences of breast cancer in either the ipsilateral or contralateral breast or elected to have the procedure for risk reduction. Patients’ satisfaction and physicians’ assessment of the cosmetic outcome were not inferior for previously irradiated compared to non-irradiated breasts. These results are encouraging and support continuing research as well as a discussion of risk-reduction alternatives besides mastectomy, including prophylactic breast irradiation, in BRCA1/2 mutation carriers.

Abstract

Risk-reducing mastectomy (RRM) is often advocated for BRCA1/2 mutation carriers who face a heightened lifetime risk of breast cancer. However, many carrier patients seek alternative risk-reducing measures. In a phase II nonrandomized trial, we previously reported that prophylactic irradiation to the contralateral breast among BRCA carriers undergoing breast-conserving treatment significantly reduced subsequent contralateral breast cancer. Herein, we report the outcome of salvage mastectomy and reconstruction in 11 patients that suffered reoccurrences of breast cancer in either the ipsilateral or contralateral breast or elected to have the procedure for risk reduction during the eight-year follow-up period. Patients’ satisfaction with the procedure and physicians’ assessment of the cosmetic outcome were not inferior for previously irradiated compared to non-irradiated breasts. Although the numbers are small, the results are encouraging and sustain hope in a challenging population. Our findings support continuing research as well as a discussion of risk-reduction alternatives besides mastectomy, including prophylactic breast irradiation, in BRCA1/2 mutation carriers.

Breast-Gynaecological & Immuno-Oncology International Cancer Conference (BGICC) Consensus and Recommendations for the Management of Triple-Negative Breast Cancer

Background: The management of patients with triple-negative breast cancer (TNBC) is challenging with several controversies and unmet needs. During the 12th Breast-Gynaecological & Immuno-oncology International Cancer Conference (BGICC) Egypt, 2020, a panel of 35 breast cancer experts from 13 countries voted on consensus guidelines for the clinical management of TNBC. The consensus was subsequently updated based on the most recent data evolved lately. Methods: A consensus conference approach adapted from the American Society of Clinical Oncology (ASCO) was utilized. The panellists voted anonymously on each question, and a consensus was achieved when ≥75% of voters selected an answer. The final consensus was later circulated to the panellists for critical revision of important intellectual content. Results and conclusion: These recommendations represent the available clinical evidence and expert opinion when evidence is scarce. The percentage of the consensus votes, levels of evidence and grades of recommendation are presented for each statement. The consensus covered all the aspects of TNBC management starting from defining TNBC to the management of metastatic disease and highlighted the rapidly evolving landscape in this field. Consensus was reached in 70% of the statements (35/50). In addition, areas of warranted research were identified to guide future prospective clinical trials.

Management of patients with BRCA mutation from the point of view of a breast surgeon

Germ-line mutation in BRCA (BReast CAncer gene) 1 or BRCA2 are found in 3–4% of all women with breast cancer. These patients have a significant increased risk of breast and ovarian cancer. They are often younger when diagnosed with the mutation, and the possible breast cancer they get is often aggressive with inferior outcome. There are risk reducing strategies, and the most powerful strategy is risk reducing surgery, both risk reducing bilateral mastectomy (RRM) and risk reducing bilateral salpino-oophorectomy (PBSO). This review is meant to address breast surgery in patients with germline BRCA mutation. The guidelines and techniques applied is under continuous change and it is important for the clinicians to be well informed to provide the patient with the information needed for them to make an informed decision on what risk strategy to choose.

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Patients with germ-line mutation in BRCA1 or BRCA2 have a significant increased risk of breast and ovarian cancer.

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There are different risk reducing strategies and the most powerful strategy is risk-reducing surgery, both risk reducing bilateral mastectomy and risk reducing bilateral salpingo-oophorectomy.

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Guidelines and techniques for the risk reducing surgery of the breast are under continuous change and improvement.

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Breast conserving therapy is not associated with worse survival and is a good option for a BRCA mutation carrier diagnosed with breast cancer. Risk-reducing mastectomy can be performed in a later setting.

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The management of BRCA mutation carriers, both affected and unaffected, should be performed in a multidisciplinary team. Physicians need to be systematically educated and updated on the most recent literature.

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.

Bilateral Mastectomy in Women With Unilateral Breast Cancer: A Review

Importance

Rates of bilateral mastectomy continue to increase in average-risk women with unilateral in situ and invasive breast cancer. Contralateral prophylactic mastectomy rates increased from 5% to 12% of all operations for breast cancer in the US from 2004 to 2012. Among women having mastectomy, rates of contralateral prophylactic mastectomy have increased from less than 2% in 1998 to 30% in 2012.

Observations

The increased use of breast magnetic resonance imaging and genetic testing has marginally increased the number of candidates for bilateral mastectomy. Most bilateral mastectomies are performed on women who are at no special risk for contralateral cancer. The true risk of contralateral breast cancer is not associated with the decision for contralateral prophylactic mastectomy; rather, the clinical factors associated with the probability of distant recurrence are associated with bilateral mastectomy. Several changes in society and health care delivery appear to act concurrently and synergistically. First, the anxiety engendered by a fear of cancer recurrence is focused on the contralateral cancer because this is most easily conceptualized and provides a ready target that can be acted upon. Second, the modern woman with breast cancer is supported by the surgeon and the social community of breast cancer survivors. Surgeons want to respect patient autonomy, despite guidelines discouraging bilateral mastectomy, and most women have their expenses covered by a third-party payer. Satisfaction with the results is high, but the association with improved psychosocial well-being remains to be fully understood.

Conclusions and Relevance

Reducing the use of medically unnecessary contralateral prophylactic mastectomy in women with nonhereditary, unilateral breast cancer requires a social change that addresses patient-, physician-, cultural-, and systems-level enabling factors. Such a transformation begins with educating clinicians and patients. The concerns of women who want preventive contralateral mastectomy must be explored, and women need to be informed of the anticipated benefits (or lack thereof) and risks. Areas requiring further study are considered.

Risk Management for BRCA1/BRCA2 mutation carriers without and with breast cancer

Purpose of review

We review the management for unaffected BRCA1/2 mutation carriers and the local management of early stage breast cancer.

Recent findings

For unaffected BRCA1/2 mutation carriers, surveillance includes annual magnetic resonance imaging (MRI) and mammogram (MG). Novel imaging modalities, including abbreviated protocol MRI, ultrafast/accelerated MRI, and contrast-enhanced digital mammography are being investigated. Risk reducing mastectomy (RRM) should be considered, and nipple-areolar sparing mastectomy (NSM) is now an option. Additionally, risk reducing salpingo-oophorectomy (RRSO) is strongly recommended as it reduces mortality.In BRCA1/2 mutation carriers with breast cancer, BCT is an appropriate treatment option but to reduce risk of second primary, mastectomy and contralateral risk-reducing mastectomy should be considered.

Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, and pancreatic cancer and recommended approaches to genetic testing/counseling and management strategies in individuals with these pathogenic or likely pathogenic variants. This manuscript focuses on cancer risk and risk management for BRCA-related breast/ovarian cancer syndrome and Li-Fraumeni syndrome. Carriers of a BRCA1/2 pathogenic or likely pathogenic variant have an excessive risk for both breast and ovarian cancer that warrants consideration of more intensive screening and preventive strategies. There is also evidence that risks of prostate cancer and pancreatic cancer are elevated in these carriers. Li-Fraumeni syndrome is a highly penetrant cancer syndrome associated with a high lifetime risk for cancer, including soft tissue sarcomas, osteosarcomas, premenopausal breast cancer, colon cancer, gastric cancer, adrenocortical carcinoma, and brain tumors.

Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk

Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS313) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS313 was quantified using Cox regression analyses. We assessed PRS313 interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS313 was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS313 was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18-1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02-1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10th percentile and 20.5% at the 90th percentile of PRS313. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS313 alone was 0.563 (95%CI = 0.547-0.586). In conclusion, PRS313 is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies.

Contralateral breast cancer risk in patients with ductal carcinoma in situ and invasive breast cancer

We aimed to assess contralateral breast cancer (CBC) risk in patients with ductal carcinoma in situ (DCIS) compared with invasive breast cancer (BC). Women diagnosed with DCIS (N = 28,003) or stage I-III BC (N = 275,836) between 1989 and 2017 were identified from the nationwide Netherlands Cancer Registry. Cumulative incidences were estimated, accounting for competing risks, and hazard ratios (HRs) for metachronous invasive CBC. To evaluate effects of adjuvant systemic therapy and screening, separate analyses were performed for stage I BC without adjuvant systemic therapy and by mode of first BC detection. Multivariable models including clinico-pathological and treatment data were created to assess CBC risk prediction performance in DCIS patients. The 10-year cumulative incidence of invasive CBC was 4.8% for DCIS patients (CBC = 1334). Invasive CBC risk was higher in DCIS patients compared with invasive BC overall (HR = 1.10, 95% confidence interval (CI) = 1.04-1.17), and lower compared with stage I BC without adjuvant systemic therapy (HR = 0.87; 95% CI = 0.82-0.92). In patients diagnosed ≥2011, the HR for invasive CBC was 1.38 (95% CI = 1.35-1.68) after screen-detected DCIS compared with screen-detected invasive BC, and was 2.14 (95% CI = 1.46-3.13) when not screen-detected. The C-index was 0.52 (95% CI = 0.50-0.54) for invasive CBC prediction in DCIS patients. In conclusion, CBC risks are low overall. DCIS patients had a slightly higher risk of invasive CBC compared with invasive BC, likely explained by the risk-reducing effect of (neo)adjuvant systemic therapy among BC patients. For support of clinical decision making more information is needed to differentiate CBC risks among DCIS patients.

Canada follows the US in the rise of bilateral mastectomies for unilateral breast cancer: a 23-year population cohort study

INTRODUCTION

The use of contralateral prophylactic mastectomy (CPM) continues to grow despite the absence of evidence supporting a survival benefit. This study's objectives were to (1) describe the trends in the rates of unilateral and bilateral mastectomy (BM) in women diagnosed with unilateral breast cancer (UBC) in Ontario, Canada from 1991 to 2013, and (2) identify factors associated with BM to treat UBC.

METHODS

This retrospective cohort analysis included all women aged 18 and older diagnosed with UBC between January 1991 and December 2013. Health administrative data from the Institute for Clinical Evaluative Sciences, the Ontario Cancer Registry, and the Discharge Abstract Database were used to identify all breast cancer and mastectomy cases. Age-adjusted mastectomy rates were plotted over time. Univariable and multivariable analyses included clinically significant covariates.

RESULTS

From 1991 to 2013 there were 172,165 cases of UBC and 64,886 mastectomies (37.7%) performed in Ontario. 13.6% of the mastectomies were bilateral. BM rates increased over sixfold (from 4 to 25%) across all age groups under age 70 over a 23-year period. On multivariable analysis, younger age, higher income, rural community, earlier breast cancer stage, lobular histology, availability of reconstruction and teaching hospitals were associated with increased odds of BM.

CONCLUSIONS

This is the largest population study of breast cancer patients in Canada and shows an increasing rate of BM for UBC. The results are similar to those already described in the US and highlight the importance of continued efforts to promote efficient communication and evidence-based decision-making prior to breast surgery.

Comparison of Patient Susceptibility Genes Across Breast Cancer: Implications for Prognosis and Therapeutic Outcomes

Hereditary breast cancer syndromes affect a small (10–15% of cases) but significant group of patients. BRCA1 and BRCA2 are the most familiar and well-studied genes associated with inherited breast cancer. However, mutations in the high-penetrance genes, TP53, PTEN, CDH1, MSH1, MLH1, MSH6, PMS2, PALB2, and STK11, and in the moderate-penetrance genes, CHEK2, ATM, and BRIP1, also correlate with high lifetime risks of breast cancer and other malignancies as well. Advances in breast cancer genetics have led to an improved perception of diagnosis and screening strategies. The specific considerations and challenges involved in treating this unique population have become a fertile ground for research. Indeed, these genes and downstream molecular pathways have now become potential therapeutic targets in breast cancer patients, including those with BRCA1 or BRCA2 mutations. This review describes the variety of hereditary breast cancer genes, from their molecular origins to the prognosis and multidisciplinary clinical decision-making processes. Key publications and other reported recent clinical trials and guidelines are provided.

The Influence of Adjuvant Systemic Regimens on Contralateral Breast Cancer Risk and Receptor Subtype

BACKGROUND

An increasing number of breast cancer (BC) survivors are at risk of developing contralateral breast cancer (CBC). We aimed to investigate the influence of various adjuvant systemic regimens on, subtype-specific, risk of CBC.

METHODS

This population-based cohort study included female patients diagnosed with first invasive BC between 2003 and 2010; follow-up was complete until 2016. Clinico-pathological data were obtained from the Netherlands Cancer Registry and additional data on receptor status through linkage with PALGA: the Dutch Pathology Registry. Cumulative incidences (death and distant metastases as competing risk) and hazard ratios (HRs) were estimated for all invasive metachronous CBC and CBC subtypes.

RESULTS

Of 83 144 BC patients, 2816 developed a CBC; the 10-year cumulative incidence was 3.8% (95% confidence interval [CI] = 3.7% to 4.0%). Overall, adjuvant chemotherapy (HR = 0.70, 95% CI = 0.62 to 0.80), endocrine therapy (HR = 0.46, 95% CI = 0.41 to 0.52), and trastuzumab with chemotherapy (HR = 0.57, 95% CI = 0.45 to 0.73) were strongly associated with a reduced CBC risk. Specifically, taxane-containing chemotherapy (HR = 0.48, 95% CI = 0.36 to 0.62) and aromatase inhibitors (HR = 0.32, 95% CI = 0.23 to 0.44) were associated with a large CBC risk reduction. More detailed analyses showed that endocrine therapy statistically significantly decreased the risk of estrogen receptor (ER)-positive CBC (HR = 0.41, 95% CI = 0.36 to 0.47) but not ER-negative CBC (HR = 1.32, 95% CI = 0.90 to 1.93) compared with no endocrine therapy. Patients receiving chemotherapy for ER-negative first BC had a higher risk of ER-negative CBC from 5 years of follow-up (HR = 2.84, 95% CI = 1.62 to 4.99) compared with patients not receiving chemotherapy for ER-negative first BC.

CONCLUSION

Endocrine therapy, chemotherapy, as well as trastuzumab with chemotherapy reduce CBC risk. However, each adjuvant therapy regimen had a different impact on the CBC subtype distribution. Taxane-containing chemotherapy and aromatase inhibitors were associated with the largest CBC risk reduction.

Breast cancer in the young patient: review of therapy and treatment considerations

In 2019, 13,050 young women were diagnosed with pre-invasive or invasive breast cancer in the USA and 1070 women died of their disease. Young women are underrepresented in clinical trials, and treatment for these women less than 40 years old is extrapolated from studies of older women. Young women face unique challenges such as decreased fertility, psychosocial issues and an extended survivorship period that impacts quality of life. Herein, we review breast cancer treatment options in the young patient (women <40 years old). We explore the biologic differences between breast cancer in young versus older patients, review surgical and systemic therapy options and highlight special considerations that are unique in these young patients.

Prediction of contralateral breast cancer: external validation of risk calculators in 20 international cohorts

BACKGROUND

Three tools are currently available to predict the risk of contralateral breast cancer (CBC). We aimed to compare the performance of the Manchester formula, CBCrisk, and PredictCBC in patients with invasive breast cancer (BC).

METHODS

We analyzed data of 132,756 patients (4682 CBC) from 20 international studies with a median follow-up of 8.8 years. Prediction performance included discrimination, quantified as a time-dependent Area-Under-the-Curve (AUC) at 5 and 10 years after diagnosis of primary BC, and calibration, quantified as the expected-observed (E/O) ratio at 5 and 10 years and the calibration slope.

RESULTS

The AUC at 10 years was: 0.58 (95% confidence intervals [CI] 0.57-0.59) for CBCrisk; 0.60 (95% CI 0.59-0.61) for the Manchester formula; 0.63 (95% CI 0.59-0.66) and 0.59 (95% CI 0.56-0.62) for PredictCBC-1A (for settings where BRCA1/2 mutation status is available) and PredictCBC-1B (for the general population), respectively. The E/O at 10 years: 0.82 (95% CI 0.51-1.32) for CBCrisk; 1.53 (95% CI 0.63-3.73) for the Manchester formula; 1.28 (95% CI 0.63-2.58) for PredictCBC-1A and 1.35 (95% CI 0.65-2.77) for PredictCBC-1B. The calibration slope was 1.26 (95% CI 1.01-1.50) for CBCrisk; 0.90 (95% CI 0.79-1.02) for PredictCBC-1A; 0.81 (95% CI 0.63-0.99) for PredictCBC-1B, and 0.39 (95% CI 0.34-0.43) for the Manchester formula.

CONCLUSIONS

Current CBC risk prediction tools provide only moderate discrimination and the Manchester formula was poorly calibrated. Better predictors and re-calibration are needed to improve CBC prediction and to identify low- and high-CBC risk patients for clinical decision-making.

The impact of lifestyle and reproductive factors on the risk of a second new primary cancer in the contralateral breast: a systematic review and meta-analysis

PURPOSE

The risk of being diagnosed with contralateral breast cancer (CBC) is an important health issue among breast cancer survivors. There is an increasing interest in the effect of lifestyle and reproductive factors on CBC risk, since these factors may partly be modifiable. We performed a systematic review and meta-analysis and aimed to evaluate the impact of lifestyle and reproductive factors on CBC risk in population-based breast cancer studies.

METHODS

The PubMed electronic database was searched up to 2nd November 2019, for relevant publications. Of the included studies, a meta-analysis per lifestyle or reproductive factor was performed.

RESULTS

Thirteen out of 784 publications were used for the meta-analysis. Body mass index (≥ 25 vs. < 25 kg/m²; RR = 1.22; 95% CI 1.01-1.47) was associated with increased CBC risk. The estimates for alcohol use (ever vs. never; RR = 1.15; 95% CI 1.02-1.31) and age at primiparity (≥ 25 vs. < 25 years; RR = 1.06; 95% CI 1.02-1.10) also showed an association with increased CBC risk. For parity (≥ 4 vs. nulliparous; RR = 0.56; 95% CI 0.42-0.76) and age at menopause (< 45 vs ≥ 45 years; RR = 0.79; 95% CI 0.67-0.93), results from two studies suggested a decreased CBC risk. We observed no association between CBC and smoking, age at menarche, oral contraceptive use, gravidity, breastfeeding, or menopausal status. Overall, the number of studies per risk factor was limited (n = 2-5).

CONCLUSIONS

BMI is a modifiable risk factor for CBC. Data on the effect of other modifiable lifestyle and reproductive factors are limited. For better counseling of patients on lifestyle effects, more studies are urgently needed.

Outcomes and risk of subsequent breast events in breast-conserving surgery patients with BRCA1 and BRCA2 mutation

Purpose

Previous studies provide inconsistent interpretations of the effect of inherited genetic factors on the survival and prognosis of patients with breast cancer. The aim of this study was to examine the effect of germline BRCA1 and BRCA2 mutation on survival and subsequent breast events in Chinese women who underwent breast‐conserving surgery.

Methods

A retrospective review of the clinical and pathological records was performed in patients diagnosed with primary invasive breast cancer between 2005 and 2018 in the cancer registry database. Clinicopathological data and data regarding treatment and outcomes, including date and site of disease progression, were collected. The survival outcomes and independent risk factors were conducted using SPSS.

Results

Overall, a total of 501 patients who underwent breast‐conserving surgery were identified and subjected to analyses, of which 63 cases with BRCA1 or BRCA2 mutation. The median age at diagnosis was 41 (range, 24‐74) for carriers and 37 (range, 17‐84) for noncarriers. After a median follow‐up time of 61 months (range, 8‐161) and 70 months (range, 0‐153), respectively, in carriers and noncarriers, the overall survival (P = .173) and disease‐free survival (P = .424) were not significantly different. Analogously, there was no significant difference between the two groups about the outcomes of ipsilateral breast tumor recurrence (P = .348), yet the contralateral breast cancer (CBC) was overt worse than noncarriers (P < .001). When adjusted to confounding factors, BRCA mutation was the only independent risk factors to CBC (HR = 7.89, P = .01).

Conclusion

In this study, BRCA mutation carriers have higher risk of CBC. And, BRCA mutation is the only independent risk factor to CBC. Therefore, intensive surveillance and follow‐up as well as more effective individual prevention are urgent. Decisions on alternatively effective prevention, especially the prevention of CBC, are urgent and should take into account patient prognosis and preferences.

Contralateral Prophylactic Mastectomy in Women with Unilateral Breast Cancer Who Are Genetic Carriers, Have a Strong Family History or Are just Young at Presentation

The uptake of contralateral prophylactic mastectomy is rising with increasing trends that are possibly highest in the USA. Whilst its role is generally accepted in carriers of recognized high-risk predisposition genes such as BRCA1 and BRCA2 when the affected individual is premenopausal, controversy surrounds the benefit in less understood risk-profile clinical scenarios. This comprehensive review explores the current evidence underpinning the role of contralateral prophylactic mastectomy and its impact on contralateral breast cancer risk and survival in three distinct at-risk groups affected by unilateral breast cancer: known genetic carriers, those with strong familial risk but no demonstrable genetic mutation and women who are of young age at presentation. The review supports the role of contralateral prophylactic mastectomy in "high risk" groups where the evidence suggests a reduction in contralateral breast cancer risk. However, this benefit is less evident in women who are just young at presentation or those who have strong family history but no demonstrable genetic mutation. A multidisciplinary and personalized approach to support individuals in a shared-decision making process is recommended.

Rate of BRCA mutation in patients tested under NCCN genetic testing criteria

BACKGROUND

BRCA genetic testing is recommended by the National Comprehensive Cancer Network (NCCN) in breast cancer patients who meet specific criteria. Limited data are available on the likelihood of detecting a mutation when these guidelines are followed.

METHODS

A retrospective chart review examined patients with breast cancer who underwent BRCA testing based on NCCN guidelines.

RESULTS

Twelve (6.0%) of the 199 patients had a deleterious BRCA mutation. Family history of BRCA mutations (50%, p = 0.019), age ≤45 at diagnosis (9.7%, p = 0.034) and meeting ≥3 NCCN criteria (13.3%, p = 0.03) yielded the highest rates of BRCA mutation. Having a family history of BRCA mutation and age ≤45 were associated with increased rate of BRCA mutation on multivariate analysis (OR 14.3, CI 1.2-166.3; OR 11.6, CI 1.2-108.6).

CONCLUSION

Select NCCN criteria are associated with higher rates of BRCA mutations. Waiting for genetic testing results to guide surgical management may be warranted in this subset of patients.

Prediction and clinical utility of a contralateral breast cancer risk model

BACKGROUND

Breast cancer survivors are at risk for contralateral breast cancer (CBC), with the consequent burden of further treatment and potentially less favorable prognosis. We aimed to develop and validate a CBC risk prediction model and evaluate its applicability for clinical decision-making.

METHODS

We included data of 132,756 invasive non-metastatic breast cancer patients from 20 studies with 4682 CBC events and a median follow-up of 8.8 years. We developed a multivariable Fine and Gray prediction model (PredictCBC-1A) including patient, primary tumor, and treatment characteristics and BRCA1/2 germline mutation status, accounting for the competing risks of death and distant metastasis. We also developed a model without BRCA1/2 mutation status (PredictCBC-1B) since this information was available for only 6% of patients and is routinely unavailable in the general breast cancer population. Prediction performance was evaluated using calibration and discrimination, calculated by a time-dependent area under the curve (AUC) at 5 and 10 years after diagnosis of primary breast cancer, and an internal-external cross-validation procedure. Decision curve analysis was performed to evaluate the net benefit of the model to quantify clinical utility.

RESULTS

In the multivariable model, BRCA1/2 germline mutation status, family history, and systemic adjuvant treatment showed the strongest associations with CBC risk. The AUC of PredictCBC-1A was 0.63 (95% prediction interval (PI) at 5 years, 0.52-0.74; at 10 years, 0.53-0.72). Calibration-in-the-large was -0.13 (95% PI: -1.62-1.37), and the calibration slope was 0.90 (95% PI: 0.73-1.08). The AUC of Predict-1B at 10 years was 0.59 (95% PI: 0.52-0.66); calibration was slightly lower. Decision curve analysis for preventive contralateral mastectomy showed potential clinical utility of PredictCBC-1A between thresholds of 4-10% 10-year CBC risk for BRCA1/2 mutation carriers and non-carriers.

CONCLUSIONS

We developed a reasonably calibrated model to predict the risk of CBC in women of European-descent; however, prediction accuracy was moderate. Our model shows potential for improved risk counseling, but decision-making regarding contralateral preventive mastectomy, especially in the general breast cancer population where limited information of the mutation status in BRCA1/2 is available, remains challenging.

Assessing the additional surgical risk of contralateral prophylactic mastectomy and immediate breast implant reconstruction

INTRODUCTION

There has been a sharp rise in the rate of contralateral prophylactic mastectomy over the last decade, despite the low incidence of new primary cancers predicted for the contralateral breast. This study compares the postoperative complication rates between the diseased breast treated with mastectomy and the contralateral breast that underwent prophylactic mastectomy, followed by immediate bilateral breast implant reconstruction. We hypothesized that there will be no difference in postoperative outcomes between prophylactic and diseased groups, as the surgical approach would be comparable.

METHODS

After IRB approval, a retrospective chart review identified consecutive unilateral breast cancer patients who underwent bilateral mastectomy and immediate breast reconstruction between May 2008 and May 2018 at a tertiary academic medical center. A paired sample t-test and a penalized logic regression model were constructed to identify relationships between breast laterality and outcomes.

RESULTS

A total of 1117 patients with unilateral breast cancer who underwent bilateral mastectomy and immediate breast implant reconstruction were identified. Rates of capsular contracture and infection were significantly greater in the diseased breast, while rates of revision were significantly greater in the contralateral prophylactic breast. There were no statistically significant differences between breasts in rates of explant, skin flap necrosis or hematoma. When adjusted for confounding variables, a higher infection rate was observed in the diseased breast.

CONCLUSION

This study detected significant differences in postoperative complication rates between the diseased and prophylactic breasts following bilateral mastectomy and immediate breast implant reconstruction. Postoperative complications occurred more frequently in the diseased breast compared with low rates of complications in the contralateral prophylactic breast. This information is helpful for preoperative decision making, as surgeons and patients carefully weigh the additional risks of contralateral prophylactic procedure.

Oncologic Safety of Prophylactic Nipple-Sparing Mastectomy in a Population With BRCA Mutations: A Multi-institutional Study

Importance

Nipple-sparing mastectomy (NSM) offers superior cosmetic outcomes and has been gaining wide acceptance; however, its role among patients with BRCA mutations remains controversial.

Objective

To report on the oncologic safety of NSM and provide evidence-based data to patients and health care professionals regarding preservation of the nipple-areolar complex during a risk-reducing mastectomy in a population with BRCA mutations.

Design, Setting, and Participants

We retrospectively reviewed the outcomes of 9 institutions' experience with prophylactic NSM from 1968 to 2013 in a cohort of patients with BRCA mutations. Patients with breast cancer were included if they underwent contralateral risk-reducing mastectomy; however, only the prophylactic side was considered in the analysis. Patients found to have an occult primary breast cancer at the time of risk-reducing mastectomy, those having variant(s) of unknown significance, and those undergoing free nipple grafts were excluded.

Main Outcomes and Measures

The primary outcome measure was development of a new breast cancer after risk-reducing NSM. Three reference data sources were used to model the expected number of events, and this was compared with our observed number of events.

Results

A total of 548 risk-reducing NSMs in 346 patients were performed at 9 institutions. The median age at NSM was 41 years (interquartile range, 34.5-47.5 years). Bilateral prophylactic NSMs were performed in 202 patients (58.4%), and 144 patients (41.6%) underwent a unilateral risk-reducing NSM secondary to cancer in the contralateral breast. Overall, 201 patients with BRCA1 mutations and 145 with BRCA2 mutations were included. With median and mean follow-up of 34 and 56 months, respectively, no ipsilateral breast cancers occurred after prophylactic NSM. Breast cancer did not develop in any patients undergoing bilateral risk-reducing NSMs. Using risk models for BRCA1/2 mutation carriers, approximately 22 new primary breast cancers were expected without prophylactic NSM. Prophylactic NSM resulted in a significant reduction in breast cancer events (test of observed vs expected events, P < .001).

Conclusions and Relevance

Nipple-sparing mastectomies are highly preventive against breast cancer in a BRCA population. Although the follow-up remains relatively short, NSM should be offered as a breast cancer risk-reducing strategy to appropriate patients with BRCA mutations.

Association of a Pathway-Specific Genetic Risk Score With Risk of Radiation-Associated Contralateral Breast Cancer

IMPORTANCE

Radiation therapy for breast cancer is associated with increased risk of a second primary contralateral breast cancer, but the genetic factors modifying this association are not well understood.

OBJECTIVE

To determine whether a genetic risk score comprising single nucleotide polymorphisms in the nonhomologous end-joining DNA repair pathway is associated with radiation-associated contralateral breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study included a case group of women with contralateral breast cancer that was diagnosed at least 1 year after a first primary breast cancer who were individually matched to a control group of women with unilateral breast cancer. Inclusion criteria were receiving a first invasive breast cancer diagnosis prior to age 55 years between 1985 and 2008. Women were recruited through 8 population-based cancer registries in the United States, Canada, and Denmark as part of the Women's Environment, Cancer, and Radiation Epidemiology Studies I (November 2000 to August 2004) and II (March 2010 to December 2012). Data analysis was conducted from July 2017 to August 2019.

EXPOSURES

Stray radiation dose to the contralateral breast during radiation therapy for the first breast cancer. A novel genetic risk score comprised of genetic variants in the nonhomologous end-joining DNA repair pathway was considered the potential effect modifier, dichotomized as high risk if the score was above the median of 74 and low risk if the score was at or below the median.

MAIN OUTCOMES AND MEASURES

The main outcome was risk of contralateral breast cancer associated with stray radiation dose stratified by genetic risk score, age, and latency.

RESULTS

A total of 5953 women were approached for study participation, and 3732 women (62.7%) agreed to participate. The median (range) age at first diagnosis was 46 (23-54) years. After 5 years of latency or more, among women who received the first diagnosis when they were younger than 40 years, exposure to 1.0 Gy (to convert to rad, multiply by 100) or more of stray radiation was associated with a 2-fold increased risk of contralateral breast cancer compared with women who were not exposed (rate ratio, 2.0 [95% CI, 1.1-3.6]). The risk was higher among women with a genetic risk score above the median (rate ratio, 3.0 [95% CI, 1.1-8.1]), and there was no association among women with a genetic risk score below the median (rate ratio, 1.3 [95% CI, 0.5-3.7]). Among younger women with a high genetic risk score, the attributable increased risk for contralateral breast cancer associated with stray radiation dose was 28%.

CONCLUSIONS AND RELEVANCE

This study found an increased risk of contralateral breast cancer that was attributable to stray radiation exposure among women with a high genetic risk score and who received a first breast cancer diagnosis when they were younger than 40 years after 5 years or more of latency. This genetic risk score may help guide treatment and surveillance for women with breast cancer.

Economic modeling of risk-adapted screen-and-treat strategies in women at high risk for breast or ovarian cancer

BACKGROUND

The 'German Consortium for Hereditary Breast and Ovarian Cancer' (GC-HBOC) offers women with a family history of breast and ovarian cancer genetic counseling. The aim of this modeling study was to evaluate the cost-effectiveness of genetic testing for BRCA 1/2 in women with a high familial risk followed by different preventive interventions (intensified surveillance, risk-reducing bilateral mastectomy, risk-reducing bilateral salpingo-oophorectomy, or both mastectomy and salpingo-oophorectomy) compared to no genetic test.

METHODS

A Markov model with a lifelong time horizon was developed for a cohort of 35-year-old women with a BRCA 1/2 mutation probability of ≥ 10%. The perspective of the German statutory health insurance (SHI) was adopted. The model included the health states 'well' (women with increased risk), 'breast cancer without metastases', 'breast cancer with metastases', 'ovarian cancer', 'death', and two post (non-metastatic) breast or ovarian cancer states. Outcomes were costs, quality of life years gained (QALYs) and life years gained (LYG). Important data used for the model were obtained from 4380 women enrolled in the GC-HBOC.

RESULTS

Compared with the no test strategy, genetic testing with subsequent surgical and non-surgical treatment options provided to women with deleterious BRCA 1 or 2 mutations resulted in additional costs of €7256 and additional QALYs of 0,43 (incremental cost-effectiveness ratio of €17,027 per QALY; cost per LYG: €22,318). The results were robust in deterministic and probabilistic sensitivity analyses.

CONCLUSION

The provision of genetic testing to high-risk women with a BRCA1 and two mutation probability of ≥ 10% based on the individual family cancer history appears to be a cost-effective option for the SHI.

Breast cancer risk in BRCA1/2 mutation carriers and noncarriers under prospective intensified surveillance

Comparably little is known about breast cancer (BC) risks in women from families tested negative for BRCA1/2 mutations despite an indicative family history, as opposed to BRCA1/2 mutation carriers. We determined the age-dependent risks of first and contralateral breast cancer (FBC, CBC) both in noncarriers and carriers of BRCA1/2 mutations, who participated in an intensified breast imaging surveillance program. The study was conducted between January 1, 2005, and September 30, 2017, at 12 university centers of the German Consortium for Hereditary Breast and Ovarian Cancer. Two cohorts were prospectively followed up for incident FBC (n = 4,380; 16,398 person-years [PY], median baseline age: 39 years) and CBC (n = 2,993; 10,090 PY, median baseline age: 42 years). Cumulative FBC risk at age 60 was 61.8% (95% CI 52.8-70.9%) for BRCA1 mutation carriers, 43.2% (95% CI 32.1-56.3%) for BRCA2 mutation carriers and 15.7% (95% CI 11.9-20.4%) for noncarriers. FBC risks were significantly higher than in the general population, with incidence rate ratios of 23.9 (95% CI 18.9-29.8) for BRCA1 mutation carriers, 13.5 (95% CI 9.2-19.1) for BRCA2 mutation carriers and 4.9 (95% CI 3.8-6.3) for BRCA1/2 noncarriers. Cumulative CBC risk 10 years after FBC was 25.1% (95% CI 19.6-31.9%) for BRCA1 mutation carriers, 6.6% (95% CI 3.4-12.5%) for BRCA2 mutation carriers and 3.6% (95% CI 2.2-5.7%) for noncarriers. CBC risk in noncarriers was similar to women with unilateral BC from the general population. Further studies are needed to confirm whether less intensified surveillance is justified in women from BRCA1/2 negative families with elevated risk.