Is the breast-conserving treatment with radiotherapy appropriate in BRCA1/2 mutation carriers? Long-term results and review of the literature

Prophylactic Salpingo-Oophorectomy and Survival After BRCA1/2 Breast Cancer Resection

Importance

Few studies have investigated whether prophylactic salpingo-oophorectomy (PSO) for patients with previously resected breast cancer who carry pathogenic germline BRCA1 or BRCA2 variants is associated with a reduced risk of cancer-specific death.

Objective

To assess the association of PSO and prophylactic mastectomy (PM) with prognosis after quadrantectomy or mastectomy as primary treatment for patients with BRCA1 or BRCA2 breast cancer.

Design, Setting, and Participants

This retrospective cohort study was performed in a single-institution, tertiary referral center. Consecutive patients with invasive breast cancer treated surgically between 1972 and 2019 were recruited and followed up prospectively after they were found to carry the BRCA1 or BRCA2 gene variant. The data analysis was performed between April 2022 and July 2023.

Exposure

Following breast surgery, some patients underwent PSO, PM, or both, whereas others did not.

Main Outcomes and Measures

The primary study end point was overall survival as measured by the Kaplan-Meier method. Secondary end points were crude cumulative incidence of breast cancer-specific mortality, ipsilateral breast tumor recurrence (IBTR), contralateral breast cancer, ovarian cancer, and ovarian cancer-specific mortality.

Results

Of 480 patients included in the cohort (median age at initial surgery, 40.0 years; IQR, 34.0-46.0 years), PSO was associated with a significantly reduced risk of death (hazard ratio [HR], 0.40; 95% CI, 0.25-0.64; P < .001). This reduction was most evident for patients carrying the BRCA1 variant (HR, 0.35; 95% CI, 0.20-0.63; P = .001), those with triple-negative disease (HR, 0.21; 95% CI, 0.09-0.46; P = .002), and those with invasive ductal carcinoma (HR, 0.51; 95% CI, 0.31-0.84; P = .008). Prophylactic salpingo-oophorectomy was not associated with risk of contralateral breast cancer or IBTR. Initial or delayed PM was associated with a reduced risk of IBTR but not with overall survival or breast cancer-specific mortality.

Conclusions

The study findings suggest that PSO should be offered to all patients with BRCA1/2 breast cancer who undergo surgery with curative intent to reduce risk of death. In particular, PSO should be offered to patients with the BRCA1 variant at the time of breast surgery.

A systematic review exploring the role of modern radiation for the treatment of Hereditary or Familial Breast Cancer

The diagnosis of hereditary or familial breast cancers influences the locoregional approach to breast cancer, with most patients undergoing mastectomy to avoid or minimize the use of adjuvant radiation therapy. We evaluated the current literature about known high- and moderate-penetrance genes and studied their impact on local control, toxicities, and contralateral breast cancers after adjuvant radiation therapy. The aim is to encourage the safe use of adjuvant radiation therapy when indicated in concordance with the updated guidelines.

Local treatment in patients with hereditary breast cancer: decision-making process in low-, moderate-, high-penetrance pathogenic germline mutation carriers

PURPOSE OF REVIEW

We summarize recent evidence regarding commonly tested breast cancer susceptibility genes and review indications derived from recently published guidelines regarding management of carriers affected by early breast cancer (BC).

RECENT FINDINGS

Management of affected women with a known genetic predisposition to BC was matter of debate at the most relevant international conferences, such as St. Gallen International Consensus Conference and San Antonio Breast Cancer Symposium held both in 2021. At the same time, a joint Experts Panel from American Society of Clinical Oncology/American Society for Radiation Oncology/Society of Surgical Oncology (ASCO/ASTRO/SSO) convened to develop recommendations to support clinical decision-making in this specific setting and results about administration of new systemic therapies such as poly adenosine diphosphate-ribose polymerase (PARP) inhibitors became available.

SUMMARY

Population of patients affected by BC and carriers of mutations in susceptibility genes is progressively increasing, but new mutations identified do not always have a clear clinical impact.To date, we have data to support consideration of different local management choices for affected patients carrying specific mutations, but some issues especially relating to breast-conserving surgery or administration of radiotherapy in these patients, still need to be better addressed. Opinions about the best way to treat these patients are still heterogeneous and information deriving from different sources seems to be conflicting at times. Our purpose is to offer a synopsis of the different evidence available that may be helpful in clinical decision making.

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.

Impact of DNA damage repair defects on response to PSMA radioligand therapy in metastatic castration-resistant prostate cancer

PURPOSE

Prostate-specific membrane antigen radioligand therapy (PSMA-RLT) is a novel treatment for castration-resistant prostate cancer (mCRPC). While the majority of patients responds to PSMA-RLT, with 10-15% having an exceptional response, approximately 30% of patients is unresponsive to PSMA-RLT. The molecular underpinning may in part explain these varying responses. This study investigated alterations in DNA damage repair (DDR) genes in tumour biopsies and their association with response to PSMA-RLT.

METHODS

A predefined retrospective cohort study was performed in mCRPC patients of whom the tumours had undergone next-generation sequencing of 40 DDR genes and received Lu-177-PSMA and/or Ac-225-PSMA-RLT. The primary outcome of this study was to compare the progression free survival (PFS) after PSMA-RLT for patients with and without pathogenic DDR aberrations in their tumour. Secondary outcomes were prostate-specific antigen (PSA) response and overall survival (OS).

RESULTS

A total of 40 patients were included of which seventeen had a tumour with a pathogenic DDR aberration (DDR+), of which eight had defects in BRCA1/2. DDR+ patients had an equal varying response to PSMA-RLT compared to those without pathological DDR anomalies (DDR-) in terms of PFS (5.9 vs. 6.4 months, respectively; HR 1.14; 95% CI 0.58-2.25; p = 0.71), ≥50% PSA response (59% vs. 65%, respectively; p = 0.75) or OS (11.1 vs. 10.7 months, respectively; HR 1.40; 95% CI: 0.68-2.91; p = 0.36).

CONCLUSION

In this study of a selected cohort, pathogenic DDR aberrations were not associated with exceptional responsiveness to PSMA-RLT. Translational studies in larger prospective cohorts are warranted to associate DDR gene defects with differential responses to PSMA-RLT.

Does breast-conserving surgery with radiotherapy in BRCA-mutation carriers significantly increase ipsilateral breast tumor recurrence? A systematic review and meta-analysis

BACKGROUND

Breast-conserving surgery (BCS) is often preferred for localized, small breast cancers, but its safety and efficacy in BRCA-mutation carriers is still controversial. This meta-analysis aimed to determine whether there was any significant difference in the incidence of ipsilateral breast tumor recurrence (IBTR) between BRCA-mutation carriers who underwent BCS and controls with sporadic breast cancer.

METHODS

A PubMed search was conducted through March 2020 to identify studies examining the risk of IBTR after BCS in BRCA-mutation carriers versus controls. The Cochrane risk-of-bias tool was used to assess the risk of bias. The pooled risk ratio (RR) was calculated using the random-effects model.

RESULTS

Thirteen studies involving 701 BRCA-mutation carriers and 4788 controls in total were eventually analyzed. In the meta-analysis, IBTR after BCS was significantly higher in BRCA-mutation carriers (RR: 1.589; 95% confidence interval (CI) 1.247-2.024; P < 0.001). Subgroup analysis of the follow-up time found that the RR for IBTR increased as the observation period lengthened (median follow-up: ≧ 7 years [RR: 1.505; 95% CI 1.184-1.913] and ≧ 10 years [RR: 1.601; 95% CI 1.201-2.132], respectively). However, a qualitative meta-analysis of overall survival in three cohort studies found no evidence to suggest a deterioration in overall survival in patients with BCS.

CONCLUSIONS

The present study demonstrated that BRCA-mutation carriers with BCS have a higher risk of IBTR, which tended to persist for a long period and become more apparent with longer observation.

Outcomes After Breast Radiation Therapy in a Diverse Patient Cohort With a Germline BRCA1/2 Mutation

PURPOSE

BRCA1/2 pathogenic variant (PV) mutations confer radiation sensitivity preclinically, but there are limited data regarding breast cancer outcomes after radiation therapy (RT) among patients with documented BRCA1/2 PV mutations versus no PV mutations.

METHODS AND MATERIALS

This retrospective cohort study included women with clinical stage I-III breast cancer who received definitive surgery and RT and underwent BRCA1/2 genetic evaluation at the The University of Texas MD Anderson Cancer Center. Rates of locoregional recurrence (LRR), disease-specific death (DSD), toxicities, and second cancers were compared by BRCA1/2 PV status.

RESULTS

Of the 2213 women who underwent BRCA1/2 testing, 63% self-reported their race as White, 13.6% as Black/African American, 17.6% as Hispanic, and 5.8% as Asian/American Indian/Alaska Native; 124 had BRCA1 and 100 had BRCA2 mutations; and 1394 (63%) received regional nodal RT. The median follow-up time for all patients was 7.4 years (95% confidence interval [CI], 7.1-7.7 years). No differences were found between the groups with and without BRCA1/2 PV mutations in 10-year cumulative incidences of LRR (with mutations: 11.6% [95% CI, 7.0%-17.6%]; without mutations: 6.6% [95% CI, 5.3%-8.0%]; P = .466) and DSD (with mutations: 12.3% [95% CI, 8.0%-17.7%]; without mutations: 13.8% [95% CI, 12.0%-15.8%]; P = .716). On multivariable analysis, BRCA1/2 status was not associated with LRR or DSD, but Black/African American patients (P = .036) and Asians/American Indians/Alaska Native patients (P = .002) were at higher risk of LRR compared with White patients, and Black/African American patients were at higher risk of DSD versus White patients (P = .004). No in-field, nonbreast second cancers were observed in the BRCA1/2 PV group. Rates of acute and late grade ≥3 radiation-related toxicity in the BCRA1/2 PV group were 5.4% (n = 12) and 0.4% (n = 1), respectively.

CONCLUSIONS

Oncologic outcomes in a diverse cohort of patients with breast cancer who had a germline BRCA1/2 PV mutation and were treated with RT were similar to those of patients with no mutation, supporting the use of RT according to standard indications in patients with a germline BRCA1/2 PV mutation.

Effect of breast-conserving surgery plus radiotherapy versus mastectomy on breast cancer-specific survival for early-stage contralateral breast cancer

Background

Breast-conserving surgery followed by radiotherapy is recommended in most women with early-stage unilateral breast cancer. However, its role in contralateral breast cancer (CBC) patients remains unclear. This retrospective study aimed to evaluate the breast cancer-specific survival (BCSS) outcomes after breast-conserving surgery plus radiotherapy compared with mastectomy in women with early-stage (T1-2N0-1M0) CBC.

Methods

Data were extracted from the Surveillance, Epidemiology, and End Results database. BCSS was analyzed using the log-rank method, competing risks regression model, and propensity score matching method.

Results

A total of 9,336 early-stage CBC patients were included. After multivariable adjustment, no significant difference in BCSS was found between early-stage CBC patients undergoing breast-conserving surgery plus radiotherapy and those undergoing mastectomy [hazard ratio (HR) 1.11, 95% confidence interval (CI): 0.90-1.37, P=0.329]. BCSS was similar in both treatment groups and in the subgroups stratified by age at first primary breast cancer or CBC diagnosis (≤50, 51-60, and >60 years), time interval between cancers (<0.25, 0.25-4, 5-9, and ≤10 years), stage of first primary breast cancer, T classification of CBC, histology and hormone receptors status of both cancers (all P>0.05). Among patients with N1 disease at CBC diagnosis, breast-conserving surgery plus radiotherapy was associated with a boundary significantly improved BCSS (HR 1.45, 95% CI: 1.00-2.12, P=0.050). Among patients who underwent breast-conserving surgery for first primary cancer, bilateral mastectomy for contralateral cancer did not improve BCSS compared with breast-conserving surgery plus radiotherapy (P>0.05). There was no significant difference in BCSS between breast-conserving surgery plus radiotherapy and mastectomy plus radiotherapy (P>0.05). Stable results were obtained after propensity score matching.

Conclusions

Breast-conserving surgery plus radiotherapy did not significantly influence BCSS outcomes of patients with early-stage CBC. Bilateral mastectomy and mastectomy plus radiotherapy did not confer a survival advantage over breast-conserving surgery plus radiotherapy in these patients. Future prospective studies are necessary to expand on these results.

Proton Therapy for Breast Cancer: A Consensus Statement From the Particle Therapy Cooperative Group Breast Cancer Subcommittee

Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage. However, there remain additional financial costs associated with proton therapy, despite reductions over time, and studies have yet to demonstrate that protons improve upon the treatment outcomes achieved with photon radiation therapy. There remains considerable heterogeneity in proton patient selection and techniques, and the rapid technological advances in the field have the potential to affect evidence evaluation, given the long latency period for breast cancer radiation therapy recurrence and late effects. In this consensus statement, we assess the data available to the radiation oncology community of proton therapy for breast cancer, provide expert consensus recommendations on indications and technique, and highlight ongoing trials' cost-effectiveness analyses and key areas for future research.

Treatment opportunities and future perspectives for pancreatic cancer patients with germline BRCA1-2 pathogenic variants

Personalized treatments and predictive biomarkers of pancreatic cancer (PDAC) are still lacking. Recently germline mutations in BRCA 1 and 2 genes, leading to homologous repair deficiency, have emerged as new targets for more specific and effective therapies, exploiting the increased susceptibility to platinum salts and PARP inhibitors. In addition to BRCA, pathogenic variants in PALB2 and in other genes involved in the DNA damage response pathway (DDR) represent potential targets, as well as their respective somatic alterations. This enlarged molecularly-selected population sharing the BRCAness phenotype, is expected to show a higher sensibility to a number of DNA damaging agents and DDR inhibitors. However, the possibility of new therapeutic opportunities for DDR defective PDAC patients has to face the lack of solid evidence about the proper type and timing of targeted-treatments, the potential combination strategies and most importantly, the lack of informations on the functional impact of each specific pathogenic variant on the DDR pathway. This review summarizes the current and near-future options for the clinical management of PDAC patients harboring a DDR deficiency, analyzing the state of the art of the indications of platinum salts and other cytotoxic agents in the advanced and early stage PDAC, the development of PARP inhibitors and the rational for new combinations with immunotherapy and cycle checkpoint inhibitors, as well as the strategy to overcome the development of resistance over treatments.

Breast Cancer Adjuvant Radiotherapy in BRCA1/2, TP53, ATM Genes Mutations: Are There Solved Issues?

BRCA1, BRCA2, TP53 and ATM gene mutations are the most studied tumour suppressor genes (TSGs) influencing the loco-regional approach to breast cancer (BC). Due to altered radio sensitivity of mutated cancer cells, mastectomy has always been advised in most patients with BC linked to TSGs mutations in order to avoid or minimize the use of adjuvant radiotherapy (ART). Whether ART is safe or not in these carriers is still debated. As a result, this issue has been widely discussed in the recent ASTRO and ASCO papers, yielding important and useful recommendations on the use of ART according to the mutational status. In this review, we have highlighted the impact of these mutations on local control, toxicities, second tumors, and contralateral breast cancers (CBCs) after ART to solve remaining doubts and encourage the safe use of ART when indicated.

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.

Comparison of Survival After Breast-Conserving Therapy vs Mastectomy Among Patients With or Without the BRCA1/2 Variant in a Large Series of Unselected Chinese Patients With Breast Cancer

Importance

Whether patients with breast cancer who carry a BRCA1/2 variant can safely undergo breast-conserving therapy (BCT) remains controversial.

Objective

To compare survival rates after BCT vs mastectomy in BRCA1/2 variant carriers and noncarriers in a large series of unselected patients with breast cancer.

Design, Setting, and Participants

In this cohort study, a large consecutive series of 8396 unselected patients with primary breast cancer underwent either BCT, mastectomy with radiotherapy, or mastectomy alone from October 1, 2003, to May 31, 2015, at the Breast Center of Peking University Cancer Hospital in China. All patients were assessed for BRCA1/2 germline variant status. Statistical analysis was performed from May 1 to September 30, 2020.

Main Outcomes and Measures

The primary outcomes were breast cancer-specific survival (BCSS) and overall survival (OS); secondary outcomes included recurrence-free survival, distant recurrence-free survival, and ipsilateral breast tumor recurrence.

Results

Of these 8396 Chinese patients (8378 women [99.8% women]; mean [SD] age, 50.8 [11.4] years; 187 BRCA1 carriers, 304 BRCA2 carriers, and 7905 noncarriers), 3135 (37.3%) received BCT, 1511 (18.0%) received mastectomy with radiotherapy, and 3750 (44.7%) received mastectomy alone. After a median follow-up of 7.5 years (range, 0.3-16.6 years), both BRCA1 and BRCA2 variant carriers treated with BCT had similar rates of survival compared with those treated with mastectomy with radiotherapy (BCSS: hazard ratio [HR] for BRCA1, 0.58 [95% CI, 0.16-2.10]; P = .41; HR for BRCA2, 0.46 [95% CI, 0.15-1.41]; P = .17; OS: HR for BRCA1, 0.61 [95% CI, 0.18-2.12]; P = .44; HR for BRCA2, 0.72 [95% CI, 0.26-1.96]; P = .52) or mastectomy alone (BCSS: HR for BRCA1, 0.70 [95% CI, 0.22-2.20]; P = .54; HR for BRCA2, 0.59 [95% CI, 0.18-1.93]; P = .39; OS: HR for BRCA1, 0.77 [95% CI, 0.27-2.21]; P = .63; HR for BRCA2, 0.62 [95% CI, 0.22-1.73]; P = .37) after adjusting for clinicopathologic factors and adjuvant therapy. For noncarriers, patients receiving BCT had significantly better survival than those receiving mastectomy with radiotherapy (BCSS: HR, 0.45 [95% CI, 0.36-0.57]; P < .001; OS: HR, 0.46 [95% CI, 0.37-0.58]; P < .001) or mastectomy alone (BCSS: HR, 0.71 [95% CI, 0.57-0.89]; P = .003; OS: HR, 0.71 [95% CI, 0.58-0.87]; P < .001) in multivariable analyses.

Conclusions and Relevance

This study suggests that BRCA1/2 variant carriers treated with BCT have survival rates at least comparable to those treated with mastectomy with radiotherapy or mastectomy alone and that BCT could be an option for BRCA1/2 variant carriers when the tumor is clinically appropriate for BCT.

Combined breast conservation therapy versus mastectomy for BRCA mutation carriers - A systematic review and meta-analysis

BACKGROUND

The non-inferiority of combined breast conservation surgery (BCS) and radiotherapy (breast conservation therapy or BCT) compared to mastectomy in sporadic breast cancer cases is well recognised. Uncertainty remains regarding optimal surgical practice in BRCA mutation carriers.

AIMS

To evaluate the oncological safety of combined BCT versus mastectomy in BRCA mutation carriers following breast cancer diagnosis.

METHODS

A systematic review was performed as per PRISMA and MOOSE guidelines. Observational studies comparing BCS and mastectomy in BRCA carriers were identified. Dichotomous variables were pooled as odds ratios (OR) using the Mantel-Haenszel method. Log hazard ratios (lnHR) for locoregional recurrence (LRR), contralateral breast cancer, disease-free and overall survival and their standard errors were calculated from Kaplan-Meier or cox-regression analyses and pooled using the inverse variance method.

RESULTS

Twenty three studies of 3807 patients met inclusion criteria; 2200 (57.7%) were BRCA1 and 1212 (31.8%) were BRCA2 carriers. Median age at diagnosis was 41 years with 96 months follow up. BCS was performed on 2157 (56.7%) while 1408 (41.5%) underwent mastectomy. An increased risk of LRR was observed in patients treated with BCS (HR:4.54, 95% Confidence Interval: 2.77-7.42, P < 0.001, heterogeneity (I2) = 0%). However, the risks of contralateral breast cancer (HR:1.51, 95%CI: 0.44-5.11, P = 0.510, I2 = 80%), disease recurrence (HR:1.16, 95%CI: 0.78-1.72, P = 0.470, I2 = 44%), disease-specific recurrence (HR:1.58, 95%CI: 0.79-3.15, P = 0.200, I2 = 38%) and death (HR:1.10, 95%CI: 0.72-1.69, P = 0.660, I2 = 38%) were equivalent for combined BCT and mastectomy.

CONCLUSIONS

Survival outcomes following combined BCT is comparable to mastectomy in BRCA carriers. However, the risk of LRR is increased. Patient counselling should be tailored to incorporate these findings.

Clinical practice of breast cancer protontherapy: A single-centre experience from selection to treatment

PURPOSE

Breast protontherapy efficiently limits cardiac, lung and contralateral breast exposure, which may clinically translate into better late tolerance profile compared with classic photon techniques. While breast protontherapy is already implemented in the United States and in some European countries, clinical experience of breast cancer protontherapy is currently limited in France. The aim of this study is to evaluate the clinical practice of breast cancer protontherapy at the Institut Curie in order to implement this technique at a larger scale.

MATERIALS AND METHODS

Data from all breast cancer patients that have been addressed to the protontherapy centre of Orsay (CPO, Institut Curie) for adjuvant breast protontherapy were retrieved. We analysed why these patients were ultimately treated with protontherapy or not.

RESULTS

Between November 2019 and November 2020, eleven breast cancer patients have been evaluated for adjuvant protontherapy at the CPO. Two of them were ultimately treated with proton beams; adjuvant breast protontherapy therapy was well tolerated. The nine other patients were not treated with protontherapy due to lack of availability of protontherapy treatment rooms in acceptable time limits, at the time of patient evaluation.

CONCLUSION

Despite dosimetric advantages and excellent clinical tolerance, lack of availability of protontherapy machines currently limits wider implementation of breast protontherapy.

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.

BRCA and Breast Cancer-Related High-Penetrance Genes

Genetic susceptibility explains 5-10% of all breast cancer cases. High-penetrance breast cancer susceptibility genes deliberate a greater than tenfold relative risk of breast cancer. BRCA1 and BRCA2 genes are the most common cause of hereditary breast cancer, and TP53, PTEN, and SKT11 (LKB1) are rarely present. The prevalence of BRCA1 and BRCA2 genetic alterations differ in various ethnic groups. The Korean Hereditary Breast Cancer (KOHBRA) Study, nationwide-scale study, was established to acquire evidence for the accurate risk assessment and management of hereditary breast and ovarian cancer (HBOC) in Korea prospectively since 2007. In this chapter, we review previous research related to hereditary breast cancer and summarize the present concepts and research results centered on the Korean Hereditary Breast Cancer Research at this time.

Locoregional Treatments and Ipsilateral Breast Cancer Recurrence Rates in BRCA1/2 Mutation Carriers

PURPOSE

There is a paucity of data on the rates of ipsilateral breast tumor recurrence (IBTR) in BRCA1/2-associated breast cancer (BC). Scarcer yet are outcomes data in BRCA1/2 mutation carriers in the setting of newer mastectomy techniques, such as skin-sparing mastectomies (SSM) and nipple-sparing mastectomies (NSM).

METHODS

Data were extracted from the medical records of BRCA1/2 carriers who were diagnosed with BC and treated at a single institution between 2006 and 2020. The data extracted included patient demographics, tumor characteristics, disease stage, surgical treatment, use of radiation therapy (RT), and disease outcome.

RESULTS

Overall, 255 BC patients with BRCA1/2 germline mutations were identified. Of these, 128 (50.2%) underwent a mastectomy (SSM or NSM in 82% of them), 76 (59.4%) without postmastectomy RT (non-PMRT) and 52 (40.6%) with PMRT, whereas 127 (49.8%) elected for breast-conserving treatment (BCT). The non-PMRT group had earlier disease stages (82.3% were Tis and T1N0) compared with the PMRT and BCT groups (3.6% and 48.1%, respectively; P < .05). The IBTR cumulative rate was 9 of 76 (11.8%) in the non-PMRT cohort compared with 0 of 52 in the PMRT group (P = .01) and 6 of 127 (4.7%) in the BCT group (P = .06). The cumulative incidences of IBTR at 5 and 10 years were 9.8% and 27.4%, respectively, in the non-PMRT group versus 2% and 11.3%, respectively, in the BCT group (P = .0183). No significant difference in overall survival was observed at the time of follow-up.

CONCLUSIONS

BRCA1/2 mutation carriers treated with mastectomy without PMRT had higher rates of IBTR than those who underwent mastectomy and PMRT or BCT, despite earlier stages of disease. The safety of SSM/NSM should be evaluated in a prospective trial.

Germline BRCA Mutation and Clinical Outcomes in Breast Cancer Patients Focusing on Survival and Failure Patterns: A Long-Term Follow-Up Study of Koreans

Background and Objectives: This study aimed to evaluate the effect of a BRCA mutation on survival and failure patterns, focusing on the risk of ipsilateral recurrence and contralateral breast cancer in patients. Materials and Methods: We retrospectively reviewed medical records of 300 patients with breast cancer who underwent genetic screening for BRCA1/2 genes and were treated at Samsung Medical Center between 1 January 2000 and 31 December 2010. Ultimately, clinical outcomes of 273 patients were analyzed. Results: The median follow-up duration was 102 months (range, 1 to 220 months). Patients with BRCA1/2-mutated tumors had a shorter 10-year disease-free survival (DFS) rate compared to those with non-mutated tumors (62.8% vs. 80.0%, p = 0.02). Regarding failure patterns, patients with BRCA1/2-mutated tumors showed a higher incidence of contralateral breast cancer than those with non-mutated tumors (BRCA1/2 non-mutated vs. mutated tumors: 4.9% vs. 26.0%, p < 0.001). BRCA mutation status remained a significant prognostic factor for contralateral breast recurrence-free survival (HR: 4.155; 95% CI: 1.789–9.652; p = 0.001). Korean patients with a BRCA mutation showed inferior DFS compared to those without a BRCA mutation. Conclusions: BRCA mutation status is a strong predictor of recurrence in contralateral breast cancer. Strategies such as prophylactic treatment and active surveillance should be discussed with breast cancer patients who have a BRCA mutation.

Management of Hereditary Breast Cancer: American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology Guideline

PURPOSE

To develop recommendations for management of patients with breast cancer (BC) with germline mutations in BC susceptibility genes.

METHODS

The American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology convened an Expert Panel to develop recommendations based on a systematic review of the literature and a formal consensus process.

RESULTS

Fifty-eight articles met eligibility criteria and formed the evidentiary basis for the local therapy recommendations; six randomized controlled trials of systemic therapy met eligibility criteria.

RECOMMENDATIONS

Patients with newly diagnosed BC and BRCA1/2 mutations may be considered for breast-conserving therapy (BCT), with local control of the index cancer similar to that of noncarriers. The significant risk of a contralateral BC (CBC), especially in young women, and the higher risk of new cancers in the ipsilateral breast warrant discussion of bilateral mastectomy. Patients with mutations in moderate-risk genes should be offered BCT. For women with mutations in BRCA1/2 or moderate-penetrance genes who are eligible for mastectomy, nipple-sparing mastectomy is a reasonable approach. There is no evidence of increased toxicity or CBC events from radiation exposure in BRCA1/2 carriers. Radiation therapy should not be withheld in ATM carriers. For patients with germline TP53 mutations, mastectomy is advised; radiation therapy is contraindicated except in those with significant risk of locoregional recurrence. Platinum agents are recommended versus taxanes to treat advanced BC in BRCA carriers. In the adjuvant/neoadjuvant setting, data do not support the routine addition of platinum to anthracycline- and taxane-based chemotherapy. Poly (ADP-ribose) polymerase (PARP) inhibitors (olaparib and talazoparib) are preferable to nonplatinum single-agent chemotherapy for treatment of advanced BC in BRCA1/2 carriers. Data are insufficient to recommend PARP inhibitor use in the early setting or in moderate-penetrance carriers. Additional information available at www.asco.org/breast-cancer-guidelines.

ASTRO Radiation Therapy Summary of the ASCO-ASTRO-SSO Guideline on Management of Hereditary Breast Cancer

PURPOSE

To develop a summary of recommendations regarding locoregional management of patients with breast cancer and germline mutations in breast cancer susceptibility genes based on the American Society of Clinical Oncology/American Society for Radiation Oncology/Society of Surgical Oncology Guideline on Management of Hereditary Breast Cancer.

METHODS

The American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology convened an expert panel to develop recommendations based on a systematic review of the literature and a formal consensus process. A total of 58 articles met the eligibility criteria and formed the evidentiary basis for the locoregional therapy recommendations. Additionally, 6 randomized controlled trials of systemic therapy also met eligibility criteria.

RESULTS

A joint evidence-based guideline was developed by a multidisciplinary panel, which has been separately published. From this guideline, the radiation-oncologist authors of the panel extracted pertinent surgical and radiation-specific recommendations of findings that are hereby presented.

CONCLUSIONS

Patients with newly diagnosed breast cancer and BRCA1/2 mutations may be considered for breast conserving therapy (BCT), expecting similar rates of local control of the index cancer as noncarriers. The significant risk of contralateral breast cancer in these women (especially younger women), coupled with the higher risk of new cancers in the ipsilateral breast, warrant discussion of bilateral mastectomy. For women with mutations in BRCA1/2 or moderate-penetrance genes who are eligible for mastectomy, nipple-sparing mastectomy is a reasonable approach. There is no evidence of increased toxicity or contralateral breast cancer events from radiation exposure in BRCA1/2 carriers. Patients with mutations in moderate-risk genes should be offered BCT as one choice after appropriate counseling. Radiation therapy should not be withheld in ATM carriers if BCT is planned. For patients with germline TP53 mutations, mastectomy is advised and radiation therapy is contraindicated except for those with a significant risk of locoregional recurrence.

Prophylactic irradiation to the contralateral breast for BRCA mutation carriers with early-stage breast cancer

BACKGROUND

Women who carry germ-line mutations in BRCA1/2 are at very high risk of developing breast and ovarian cancer. Breast conserving therapy is associated with a similar risk of ipsilateral cancer recurrence in BRCA carriers compared with non-carriers. However, the risk of subsequent contralateral breast cancer in carriers is markedly increased. Therefore, mastectomy of the diseased breast along with risk reducing mastectomy of the contralateral breast is often advocated for BRCA carriers who are treated for early breast cancer. Yet, many BRCA carriers forgo this option for fear of harmful effects and choose breast conserving treatment and observation instead. In Israel, BRCA-associated breast cancer is relatively common. Accordingly, a national protocol was devised for this enriched population.

PATIENTS AND METHODS

In this Institutional Review Board-approved phase II trial, the option of prophylactic irradiation to the contralateral breast, in addition to standard loco-regional treatment, was offered to BRCA carrier patients treated for early breast cancer who declined contralateral mastectomy. The primary end point was contralateral breast cancer.

RESULTS

Between May 2007 and October 2017, 162 patients were enrolled. Eighty-one patients opted for standard loco-regional treatment including surgery and radiation to the involved side (control arm) and 81 patients chose additional contralateral breast irradiation (intervention arm). At a median follow-up of 58 months, 10 patients developed contralateral breast cancer in the control arm at a median of 32 months, as compared with 2 patients in the intervention arm who developed contralateral breast cancer 80 and 105 months after bilateral breast irradiation (log-rank P = 0.011).

CONCLUSIONS

Among BRCA carrier patients treated for early breast cancer, the addition of contralateral breast irradiation was associated with a significant reduction of subsequent contralateral breast cancers and a delay in their onset.

CLINICAL TRIAL

Phase II, comparative two-arm trial (NCT00496288).

BRCA1/BRCA2 Pathogenic Variant Breast Cancer: Treatment and Prevention Strategies

Hereditary breast cancer is known for its strong tendency of inheritance. Most hereditary breast cancers are related to BRCA1/BRCA2 pathogenic variants. The lifelong risk of breast cancer in pathogenic BRCA1 and BRCA2 variant carriers is approximately 65% and 45%, respectively, whereas that of ovarian cancer is estimated to be 39% and 11%, respectively. Therefore, understanding these variants and clinical knowledge on their occurrence in breast cancers and carriers are important. BRCA1 pathogenic variant breast cancer shows more aggressive clinicopathological features than the BRCA2 pathogenic variant breast cancer. Compared with sporadic breast cancer, their prognosis is still debated. Treatments of BRCA1/BRCA2 pathogenic variant breast cancer are similar to those for BRCA-negative breast cancer, mainly including surgery, radiotherapy, and chemotherapy. Recently, various clinical trials have investigated poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor treatment for advanced-stage BRCA1/BRCA2 pathogenic variant breast cancer. Among the various PARP inhibitors, olaparib and talazoparib, which reached phase III clinical trials, showed improvement of median progression-free survival around three months. Preventive and surveillance strategies for BRCA pathogenic variant breast cancer to reduce cancer recurrence and improve treatment outcomes have recently received increasing attention. In this review, we provide an information on the clinical features of BRCA1/BRCA2 pathogenic variant breast cancer and clinical recommendations for BRCA pathogenic variant carriers, with a focus on treatment and prevention strategies. With this knowledge, clinicians could manage the BRCA1/BRCA2 pathogenic variant breast cancer patients more effectively.

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 Breast Cancer and Ipsilateral Breast Tumor Recurrence in BRCA1/2 Carriers and Non-Carriers at High-Risk of Hereditary Breast Cancer

Purpose

We evaluated the risk of contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) and investigated the predictive factors for CBC and IBTR in breast cancer patients with BRCA mutations and non-carriers at high-risk of hereditary breast and ovarian cancer (HBOC).

Methods

We analyzed prospectively collected clinical data of patients with unilateral breast cancer who were at high-risk for HBOC and were tested for the BRCA mutation between 2003 and 2013.

Results

The cohort comprised 540 patients with 45 BRCA1 carriers, 50 BRCA2 carriers, and 445 non-carriers. The median follow-up was 84.5 months. Overall, 61 patients (11.3%) developed CBC (24.4% for BRCA1 carriers, 20% for BRCA2 carriers, and 9% for non-carriers). The 10-year cumulative risk for CBC was 23.8% for BRCA1 carriers, 19.1% for BRCA2 carriers, and 9.8% for non-carriers (p = 0.174). Among the 277 patients who underwent breast-conserving surgery, 29 (10.5%) developed IBTR (9.1% for BRCA1 carriers, 16.7% for BRCA2 carriers, and 10.2% for non-carriers). The 10-year cumulative risk for IBTR for BRCA1 carriers, BRCA2 carriers, and non-carriers was 8.7%, 14.1%, and 20%, respectively (p = 0.577). BRCA1 (hazard ratio [HR], 2.94; 95% confidence interval [CI], 1.20-7.20; p = 0.019) and BRCA2 (HR, 2.88; 95% CI, 1.13-7.35; p = 0.027) mutations and negative estrogen receptor status (HR, 4.02; 95% CI, 1.60-10.08; p = 0.003) were the significant predictive factors for CBC, while tumor size ≥ 2 cm was predictive of IBTR (HR, 6.11; 95% CI, 2.03-18.33; p = 0.001).

Conclusion

While BRCA1/2 mutation carriers had a higher risk of developing CBC compared to non-carriers at high-risk of HBOC, the risk of IBTR was similarly high across breast cancer patients irrespective of the BRCA mutation. Further preventive strategies to reduce CBC and IBTR for all patients at high-risk of HBOC should be investigated.

Breast Conserving Surgery for BRCA Mutation Carriers-A Systematic Review

Similar to mastectomy, breast conserving surgery (BCS) is currently the reference standard of surgical treatment of sporadic breast cancer in patients. However, its oncologic safety for BRCA mutation carriers has remained controversial. Thus, we conducted a systematic review to critically evaluate the best evidence from reported studies. A comprehensive search was performed of the Medline, EMBASE, CINAHL, and Cochrane databases using a predefined strategy. The retrieved studies were independently screened and rated for relevance. Data were extracted for qualitative synthesis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol for systematic reviews. No randomized controlled trial has directly compared BCS and mastectomy for BRCA mutation carriers. Of the 18 studies included in our review, the pooled analysis of overall survival at 5, 10, and 15 years were comparable between BCS and mastectomy (88.7%, 89.0% and 83.6% with BCS and 83%, 86.0%, and 83.2% with mastectomy, respectively). However, the pooled ipsilateral breast cancer recurrence rates at 5, 10, and 15 years were higher in the BCS group (8.2%, 15.5%, and 23%, respectively) than in the mastectomy group (3.4%, 4.9%, and 6.4%, respectively). BCS was associated with a greater rate of ipsilateral breast cancer recurrence in BRCA mutation carriers. However, it was not associated with adverse short- and long-term survival outcomes. BCS should be offered as an option to BRCA mutation carriers with proper preoperative counseling.

Molecular characteristics of breast cancer according to clinicopathological factors

The purpose of the present study was to evaluate the correlation between molecular factors such as BRCA1 DNA repair associated (BRCA1), checkpoint kinase 2 (CHEK2) and nucleotide binding oligomerization domain containing 2 (NOD2) gene mutations and clinicopathological factors in patients with breast cancer (BC). Prognostic factors were analyzed in BC patients with confirmed BRCA1 (n=73), CHEK2 (n=51) and NOD2 (n=31) mutations. The control group was selected from BC patients without mutations (n=392). The BRCA-associated cancer cases were significantly more often triple negative compared with sporadic cancer (62% vs. 14%; P=0.0001). Luminal B HER2-positive and HER2-positive non-luminal subtypes were observed more often in the control group (33 and 17%). The luminal A subtype was detected in 53% of CHEK2 mutation carriers and 45% of NOD2 mutation carriers. A lower histological grade was observed significantly more often in patients with CHEK2 mutations in comparison with the control group (88 vs. 69%; P=0.003). Lymph nodes without metastases were reported more frequently in NOD2 mutation carriers (74 vs. 54%; P=0.038), in BRCA1 mutations (73 vs. 54%; P=0.004) and, although not significantly, in CHEK2 mutation carriers (69 vs. 54%; P=0.071) compared with the control group. In conclusion, BRCA1 mutation was associated with TNBC and the luminal B HER2 (-) subtype. HER2-positive subtypes were characteristic of the control group. CHEK2 and NOD2 mutation carriers had a more favorable profile of prognostic factors.

Germline Genetic Testing for Breast Cancer Risk: The Past, Present, and Future

The field of germline genetic testing for breast cancer (BC) risk has evolved substantially in the last decade. The introduction of multigene panel testing (MGPT) led to an urgent need to understand the cancer risk associated with several genes included in the panels. Although the research on understanding the cancer risk associated with mutations in several genes continues, there is also a need to understand the modifying effects of race and ethnicity, family history, and BC pathology on the prevalence of germline mutations and associated BC risk. Furthermore, polygenic risk scores (PRSs) to predict BC risk in patients with or without germline mutations in cancer-predisposition genes are now available for clinical use, although data on the clinical utility of PRSs are lacking. In patients with advanced BC associated with BRCA1/2 mutation, olaparib and talazoparib are now approved for treatment. In addition, molecular profiling studies are being used to clarify the BC tumor biology in mutation carriers to identify potential therapeutic options. In this article, we discuss these advances in the field of germline genetic testing and highlight current limitations and implications for clinical care.

Is breast-conserving therapy adequate in BRCA 1/2 mutation carriers? The radiation oncologist's point of view

Breast conserving therapy (BCT) is currently a recognized alternative to mastectomy for early BC patients. However, the therapeutic index of BCT was considered controversial for decades in BRCA1/2 mutation carriers. The aim of the present review was to investigate the outcome of mutation carriers undergoing BCT regarding local and distant endpoints. A short review was performed from the point of view of the radiation oncologist. Only retrospective data were available regarding local outcome assessment. They generated conflicting results. In studies with limited follow-up, BCT did not increase the risk of local recurrence in BRCA1/2 mutation carriers versus non-carriers. Conversely, some studies with longer follow-up supported that local relapse was increased in mutation carriers. Yet, according to some publications, their long-term risk of ipsilateral recurrence post-BCT was not different from general population cohorts. Besides, overall and metastasis-free survivals were the same after BCT regardless of the BRCA1/2 mutation status. Similar survival rates were also reported when BCT and mastectomy were compared in mutation carriers. Regarding acute or late toxicity, normal rates were reported in BRCA mutation carriers after breast radiotherapy. The BRCA1/2 mutation does not seem to widely alter the therapeutic index (efficacy/toxicity ratio) of modern adjuvant breast irradiation. Although the long term equivalence of BCT/mastectomy on local control is still not clearly recognised, BCT can be considered an adequate option for BRCA1/2 mutation carriers. This review highlights that BCT is a reasonable option for BRCA1/2 mutation carriers however litterature is controversial concerning long-term local outcome and results of a large prospective cohort are needed.

BRCA1/BRCA2 mutations in Japanese women with ductal carcinoma in situ

Background

Ductal carcinoma in situ (DCIS) is considered a component of the clinical spectrum of breast cancer even in those with BRCA1/2 mutation. The aim of this study was to report the feature of DCIS raised in Japanese women with BRCA1/2 mutations.

Methods

A total of 325 Japanese women with breast cancer (BC) (with or without invasive cancer) were referred for genetic counseling and underwent genetic testing for mutations in the BRCA1 and BRCA2 genes in Showa University Hospital between December 2011 and August 2016. And 49 of them who were pathologically diagnosed as DCIS were included in this study. Logistic regression models were fit to determine the associations between potential predictive factors and BRCA status. A Cox proportional hazards model is used to predictive value of parameters for Ipsilateral breast tumor recurrence (IBTR) and contralateral breast tumor recurrence (CBTR).

Results

(a) Of 325 patients (with or without invasive cancer), 19.1% (62/325) tested positive for BRCA1/BRCA2 mutations. And 18.4% (9/49) was positive for BRCA1/BRCA2 mutations in DCIS, compared with 19.2% (53/276) in IDC (p = 1.000). Among BRCA mutations, 14.5% (9/62) had DCIS compared with nonmutations (15.2%, 40/263). Incidence of DCIS was 3.0% (1/33) of BRCA1 mutations and 27.5% (8/29) of BRCA2 mutation (p = 0.009). (b) Median age of diagnosis in BRCA mutation carriers was 39 years, compared with 46 years in noncarriers. Age, Family history (FH) of BC, FH of first or second BC and total number of relatives with BC diagnosis (DX) has significant difference between BRCA mutation carriers and noncarriers in univariate analysis. In a multivariate logistic model, total relatives with BC DX ≥ 2 (odds ratio [OR], 5.128; 95% confidence interval [CI], 1.266–20.763; p = 0.022), age at diagnosis ≤35 years (OR 0.149, 95% CI 0.023–0.954, p = 0.045) and ER+/HER2+ status (OR 5.034, 95% CI 1.092–23.210, p = 0.038) remained as independent significant predictors for BRCA mutation. Ki67 index (cut off by 14% or 30%) did not differ between BRCA mutation carriers and noncarriers (p = 0.459 and p = 0.651). (c) There was a significant difference in ER‐positive tumors among BRCA2 carriers and noncarriers (p = 0.042). Subgroup analysis showed BRCA2 carriers tend to be of higher grade (Grade 2 and 3), more frequently ER+/PR+ (p = 0.041) and lower proliferation (Ki67 index) than noncarriers, whereas differences in nuclear grade and ki67 index were not found significantly in our study. (d) BRCA mutation was not associated with an increased risk of IBTR and CBTR.

Conclusion

DCIS is equally as prevalent in patients who were BRCA mutation carriers as in high familial‐risk women who were noncarriers, but occurs at earlier age. BRCA2 carriers have higher incidence in DCIS than that of BRCA1 carriers, and tend to be higher grade and more frequently ER positive and lower proliferation. Total relatives with BC DX ≥2, age at diagnosis ≤35 years and ER+/HER2+ might be independent predictors for BRCA mutation in Japanese women with DCIS and patients of these risk factors should be recommended to receive genetic counseling and BRCA testing.

The association between non-breast and ovary cancers and BRCA mutation in first- and second-degree relatives of high-risk breast cancer patients: a large-scale study of Koreans

Background

As a large-scale study of Koreans, we evaluated the association between BRCA mutation and the prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients.

Methods

We organized familial pedigrees of 2555 patients with breast cancer who underwent genetic screening for BRCA1/2 in Samsung Medical Center between January 2002 and May 2018. Families with a member that had a history of cancer other than of the breast or ovary were regarded positive for other primary cancer.

Results

The median age of the population was 40 years (range, 19 to 82 years). BRCA mutation was detected in 377 (14.8%) of the patients. The BRCA-positive group had a higher frequency of family history of breast or ovarian cancer (p <  0.001), bilateral breast cancer (p = 0.021), and the male gender (p = 0.038). There were 103 (27.3%) patients who had multiple risk factors in the BRCA-positive group, while there were 165 (7.6%) patients who had multiple risk factors in the BRCA-negative group (p <  0.001). BRCA mutation was detected in 215 (11.7%) of the 1841 families without history of other primary cancers. Among the 714 families with histories of other primary cancers, 162 (22.7%) had BRCA mutation, and this was significantly more frequent (p < 0.001) than in those without a history. The occurrence of other primary cancers in families of high-risk patients was associated with a younger age at diagnosis (p = 0.044), bilateral breast cancer (p = 0.006), and BRCA mutations (p < 0.001). The most common site for the occurrence of another type of primary cancer was the stomach. In the BRCA-positive group, the proportional incidences of stomach, pancreas, colorectal, lung, and uterine cancer were 13.8, 4.0, 7.7, 8.8, and 5.0%, respectively; these were all relatively higher than those in the BRCA-negative group.

Conclusions

We confirmed that BRCA mutation was associated with having multiple risk factors and an increased prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients. Due to the possibility of inherited cancer risk, genetic counseling with options for risk assessment and management should be provided to both patients and families of BRCA mutation carriers.

Fanconi anemia and homologous recombination gene variants are associated with functional DNA repair defects in vitro and poor outcome in patients with advanced head and neck squamous cell carcinoma

Mutations in Fanconi Anemia or Homologous Recombination (FA/HR) genes can cause DNA repair defects and could therefore impact cancer treatment response and patient outcome. Their functional impact and clinical relevance in head and neck squamous cell carcinoma (HNSCC) is unknown. We therefore questioned whether functional FA/HR defects occurred in HNSCC and whether they are associated with FA/HR variants. We assayed a panel of 29 patient-derived HNSCC cell lines and found that a considerable fraction is hypersensitive to the crosslinker Mitomycin C and PARP inhibitors, a functional measure of FA/HR defects. DNA sequencing showed that these hypersensitivities are associated with the presence of bi-allelic rare germline and somatic FA/HR gene variants. We next questioned whether such variants are associated with prognosis and treatment response in HNSCC patients. DNA sequencing of 77 advanced stage HNSCC tumors revealed a 19% incidence of such variants. Importantly, these variants were associated with a poor prognosis (p = 0.027; HR = 2.6, 1.1–6.0) but favorable response to high cumulative cisplatin dose. We show how an integrated in vitro functional repair and genomic analysis can improve the prognostic value of genetic biomarkers. We conclude that repair defects are marked and frequent in HNSCC and are associated with clinical outcome.

Genetic testing in women with breast cancer: implications for treatment

INTRODUCTION

Mutations in either the BRCA1 or BRCA2 genes are responsible for approximately 42,000 cases of breast cancer annually. Identifying these germline mutations in a woman with breast cancer is important because it can influence her immediate and long-term management and has important implications for other family members. Areas covered: This review highlights how treatment-focussed genetic testing for BRCA1 and BRCA2 mutations can potentially influence cancer treatment and secondary prevention decisions in women with breast cancer. Expert commentary: Testing women with breast cancer for BRCA1 and BRCA2 germline mutations has the potential to decrease cancer burden and improve cancer outcomes. It can help optimise surgical and systemic therapy approaches. Clinicians should actively consider whether genetic testing is appropriate for each woman with breast cancer, and if so should instigate it early in the treatment trajectory when it can most influence cancer care.

Lymph node status as a prognostic factor in BRCA-positive breast cancer

BACKGROUND

The incidence of ipsilateral breast tumor recurrence (IBTR) seems to be higher in BRCA-positive than sporadic breast cancer. We compared the oncologic outcomes of BRCA-positive breast cancer patients managed with breast-conserving surgery, simple mastectomy or mastectomy followed by immediate reconstruction.

MATERIALS/METHODS

Thirty four BRCA-positive breast cancers were grouped according to surgical treatment: breast-conserving surgery (n = 17), simple mastectomy (n = 9), and mastectomy followed by immediate reconstruction (n = 8). Clinicopathologic factors and oncologic outcomes were compared during a 3-y mean follow-up.

RESULTS

Neoadjuvant radiotherapy and nodal and pathologic stages differed significantly between the breast-conserving and simple mastectomy groups. There was no oncologic event in the breast-conserving group during follow-up; however, IBTR and distant metastasis occurred in the simple mastectomy and mastectomy followed by immediate reconstruction groups. Nodal stage was associated with IBTR in both these groups whereas pathologic stage was associated with distant metastasis only in the simple mastectomy group.

CONCLUSIONS

Although there were no differences in oncologic outcomes between the three groups, the nodal stage was strongly associated with IBTR in patients with BRCA-positive breast cancer. IBTR may be attributable to nodal stage and pathologic tumor stage.

Impact that Timing of Genetic Mutation Diagnosis has on Surgical Decision Making and Outcome for BRCA1/BRCA2 Mutation Carriers with Breast Cancer

BACKGROUND

Deleterious BRCA mutation carriers with breast cancer are at increased risk for additional breast cancer events. This study evaluated the impact that timing of identification of BRCA+ status has on surgical decision and outcome.

METHODS

The authors reviewed all BRCA carriers at their institution whose breast cancer was diagnosed between January 1996 and June 2015. Patient surveys, medical records, and institutional databases were used to collect data. Differences in surgical choice were analyzed using the chi-square test, and rates of subsequent breast cancer events were estimated using the Kaplan-Meier method.

RESULTS

The study investigated 173 BRCA carriers with breast cancer (100 BRCA1, 73 BRCA2). Of the women with known BRCA mutation before surgery and unilateral stages 0 to 3 breast cancer (n = 63), 12.7 % underwent lumpectomy, 4.8 % underwent unilateral mastectomy (UM), and 82.5 % underwent bilateral mastectomy (BM). These surgical choices differed significantly (p < 0.0001) from those of patients unaware of their mutation at the time of surgery (n = 93) (51.6 % had lumpectomy, 19.4 % had UM, 29 % had BM). Of the patients with BRCA mutation identified after surgery who underwent lumpectomy or UM, 36 (59 %) of 66 underwent delayed BM. The patients with BRCA+ known before diagnosis presented with significantly lower-stage disease (p = 0.02) at diagnosis (69 % stage 0 or 1) than those whose BRCA mutation was identified after cancer diagnosis (40 % stage 0 or 1).

CONCLUSIONS

The study findings showed that BRCA mutation status influences surgical decision. The rates of BM were higher for the patients with BRCA mutation known before surgery. Identification of BRCA mutation after surgery frequently leads to subsequent breast surgery. Genetic testing before surgery is important for patients at elevated risk for BRCA mutation.

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

PURPOSE

To determine prospectively overall and age-specific estimates of contralateral breast cancer (CBC) risk for young patients with breast cancer with or without BRCA1/2 mutations.

PATIENTS AND METHODS

A cohort of 6,294 patients with invasive breast cancer diagnosed under 50 years of age and treated between 1970 and 2003 in 10 Dutch centers was tested for the most prevalent BRCA1/2 mutations. We report absolute risks and hazard ratios within the cohort from competing risk analyses.

RESULTS

After a median follow-up of 12.5 years, 578 CBCs were observed in our study population. CBC risk for BRCA1 and BRCA2 mutation carriers was two to three times higher than for noncarriers (hazard ratios, 3.31 [95% CI, 2.41 to 4.55; P < .001] and 2.17 [95% CI,1.22 to 3.85; P = .01], respectively). Ten-year cumulative CBC risks were 21.1% (95% CI, 15.4 to 27.4) for BRCA1, 10.8% (95% CI, 4.7 to 19.6) for BRCA2 mutation carriers and 5.1% (95% CI, 4.5 to 5.7) for noncarriers. Age at diagnosis of the first breast cancer was a significant predictor of CBC risk in BRCA1/2 mutation carriers only; those diagnosed before age 41 years had a 10-year cumulative CBC risk of 23.9% (BRCA1: 25.5%; BRCA2: 17.2%) compared with 12.6% (BRCA1: 15.6%; BRCA2: 7.2%) for those 41 to 49 years of age (P = .02); our review of published studies showed ranges of 24% to 31% before age 40 years (BRCA1: 24% to 32%; BRCA2:17% to 29%) and 8% to 21% after 40 years (BRCA1: 11% to 52%; BRCA2: 7% to 18%), respectively.

CONCLUSION

Age at first breast cancer is a strong risk factor for cumulative CBC risk in BRCA1/2 mutation carriers. Considering the available evidence, age-specific risk estimates should be included in counseling.

BRCA1 Mutation: A Predictive Marker for Radiation Therapy?

DNA repair, in particular, DNA double-strand break (DSB) repair, is essential for the survival of both normal and cancer cells. An elaborate repair mechanism has been developed in cells to efficiently repair the damaged DNA. The pathways predominately involved in DSB repair are homologous recombination and classic nonhomologous end-joining, although the alternative NHEJ pathway, a third DSB repair pathway, could also be important in certain contexts. The protein of BRCA1 encoded by the tumor suppressor gene BRCA1 regulates all DSB repair pathways. Given that DSBs represent the most biologically significant lesions induced by ionizing radiation and that impaired DSB repair leads to radiation sensitivity, it has been expected that cancer patients with BRCA1 mutations should benefit from radiation therapy. However, the clinical data have been conflicting and inconclusive. We provide an overview about the current status of the data regarding BRCA1 deficiency and radiation therapy sensitivity in both experimental models and clinical investigations. In addition, we discuss a strategy to potentiate the effects of radiation therapy by poly(ADP-ribose) polymerase inhibitors, the pharmacologic drugs being investigated as monotherapy for the treatment of patients with BRCA1/2 mutations.

Long-term effects of first degree family history of breast cancer in young women: Recurrences and bilateral breast cancer

BACKGROUND

The aim of this study is to analyze the impact of first degree relative (FDR) of young breast cancer patients.

METHODS

Data were used from our prospective population-based cohort study which started in 1983. The family history (FH) was registered with regard to FDR: the presence or absence of invasive breast cancer in none vs. one or more FDRs at any age.

RESULTS

A total of 1109 women, ≤50 years with 1128 breast conserving treatments was seen. The incidence of FDR was 17.0% for one FDR and 3.2% ≥2 FDR. The three groups, none, 1 or ≥2 FDR, were comparable. The local failure rate is comparable for all three groups. Women with a positive FH and metachronous bilateral breast cancer (MBBC) showed a lower local failure (HR 0.2; 95% CI 0.05-0.8). A positive FH was an independent predictor for a better disease-specific survival (HR 0.6; 95% CI 0.4-0.9).

CONCLUSION

A positive FH, based on FDR implies a better prognosis in relation to survival for young women treated with BCT. In contrast to no FH for FDR, MBBC in women with a positive FH was not associated with an increased risk of local recurrence.

Effect of BRCA Mutations on Metastatic Relapse and Cause-specific Survival After Radical Treatment for Localised Prostate Cancer

BACKGROUND

Germline BRCA mutations are associated with worse prostate cancer (PCa) outcomes; however, the most appropriate management for mutation carriers has not yet been investigated.

OBJECTIVE

To evaluate the response of BRCA carriers to conventional treatments for localised PCa by analysing metastasis-free survival (MFS) and cause-specific survival (CSS) following radical prostatectomy (RP) or external-beam radiation therapy (RT).

DESIGN, SETTING, AND PARTICIPANTS

Tumour features and outcomes of 1302 patients with local/locally advanced PCa (including 67 BRCA mutation carriers) were analysed. RP was undergone by 535 patients (35 BRCA); 767 received RT (32 BRCA). Median follow-up was 64 mo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Median survival and 3-, 5-, and 10-yr survival rates were estimated using the Kaplan-Meier method. Generated survival curves were compared using the log-rank test. Cox regression analyses were used to assess the prognostic value of BRCA mutations.

RESULTS AND LIMITATIONS

A total of 67 BRCA carriers and 1235 noncarriers were included. At 3, 5, and 10 yr after treatment, 97%, 94%, and 84% of noncarriers and 90%, 72%, and 50% of carriers were free from metastasis (p<0.001). The 3-, 5- and 10-yr CSS rates were significantly better in the noncarrier cohort (99%, 97%, and 85%, respectively) than in carriers (96%, 76%, and 61%, respectively; p<0.001). Multivariate analysis confirmed BRCA mutations as an independent prognostic factor for MFS (hazard ratio [HR]: 2.36; 95% confidence interval [CI], 1.38-4.03; p=0.002) and CSS (HR: 2.17; 95% CI, 1.16-4.07; p=0.016).

CONCLUSIONS

BRCA carriers had worse outcomes than noncarriers when conventionally treated for local/locally advanced PCa.

PATIENT SUMMARY

Prostate cancer patients with germline BRCA mutations had worse outcomes than noncarriers when conventionally treated with surgery or radiation therapy.

Worse breast cancer prognosis of BRCA1/BRCA2 mutation carriers: what's the evidence? A systematic review with meta-analysis

Objective

Conflicting conclusions have been published regarding breast cancer survival of BRCA1/2 mutation carriers. Here we provide an evidence-based systematic literature review.

Methods

Eligible publications were observational studies assessing the survival of breast cancer patients carrying a BRCA1/2 mutation compared to non-carriers or the general breast cancer population. We performed meta-analyses and best-evidence syntheses for survival outcomes taking into account study quality assessed by selection bias, misclassification bias and confounding.

Results

Sixty-six relevant studies were identified. Moderate evidence for a worse unadjusted recurrence-free survival for BRCA1 mutation carriers was found. For BRCA1 and BRCA2 there was a tendency towards a worse breast cancer-specific and overall survival, however, results were heterogeneous and the evidence was judged to be indecisive. Surprisingly, only 8 studies considered adjuvant treatment as a confounder or effect modifier while only two studies took prophylactic surgery into account. Adjustment for tumour characteristics tended to shift the observed risk estimates towards a relatively more favourable survival.

Conclusions

In contrast to currently held beliefs of some oncologists, current evidence does not support worse breast cancer survival of BRCA1/2 mutation carriers in the adjuvant setting; differences if any are likely to be small. More well-designed studies are awaited.

Clinical relevance of normal and tumour cell radiosensitivity in BRCA1/BRCA2 mutation carriers: a review

Women harbouring BRCA1/2 mutations are known to be at higher lifetime risk of developing breast cancer than non-carriers. Compared to mastectomy, conservative surgery is also associated, in this patient population, with a higher probability to developing recurrent ipsilateral breast cancer following primary treatment. To reduce these risks, the management of BRCA1/2 - associated cancers has therefore focused on optimal prophylactic and therapeutic interventions at the time of diagnosis. In a recent past, comparative analyses of radiosensitivity levels have been carried out in murine embryos harbouring BRCA1/2 gene mutation and in non-carriers. The fact that a number of these experimental data are in favour of higher radiosensitivity levels in carriers of germline mutations leads to concern regarding the potential consequences of exposure to radiation, especially in terms of excessive toxicity in normal tissues and radiation-induced malignancies. The objective of this review is to determine whether or not the potentially higher radiosensitivity of normal and tumour cells has a clinical relevance in BRCA1/2 mutations carriers in terms of disease control, acute and late adverse events, and tumourigenesis.

Medical factors influencing decision making regarding radiation therapy for breast cancer

Radiation therapy is an important and effective adjuvant therapy for breast cancer. Numerous health conditions may affect medical decisions regarding tolerance of breast radiation therapy. These factors must be considered during the decision-making process after breast-conserving surgery or mastectomy for breast cancer. Here, we review currently available evidence focusing on medical conditions that may affect the patient-provider decision-making process regarding the use of radiation therapy.