The risks of cancer in older women with BRCA pathogenic variants: How far have we come?

BACKGROUND: The purpose of this study was to estimate the cumulative risks of all cancers in women from 50 to 75 years of age with a BRCA1 or BRCA2 pathogenic variant. METHODS: Participants were women with BRCA1 or BRCA2 pathogenic variants from 85 centers in 16 countries. Women were eligible if they had no cancer before the age of 50 years. Participants completed a baseline questionnaire and follow-up questionnaires every 2 years. Women were followed from age 50 until a diagnosis of cancer, death, age 75, or last follow-up. The risk of all cancers combined from age 50 to 75 was estimated using the Kaplan-Meier method. RESULTS: There were 2211 women included (1470 BRCA1 and 742 BRCA2). There were 379 cancers diagnosed in the cohort between 50 and 75 years. The actuarial risk of any cancer from age 50 to 75 was 49% for BRCA1 and 43% for BRCA2. Breast (n = 186) and ovarian (n = 45) were the most frequent cancers observed. For women who had both risk-reducing mastectomy and bilateral salpingo-oophorectomy before age 50, the risk of developing any cancer between age 50 and 75 was 9%. CONCLUSION: Women with a BRCA1 or BRCA2 pathogenic variant have a high risk of cancer between the ages of 50 and 75 years and should be counselled appropriately.

Adjuvant Olaparib for Germline BRCA Carriers With HER2-Negative Early Breast Cancer: Evidence and Controversies.

In the OlympiA study, 1 year of adjuvant olaparib significantly extended invasive disease-free survival and overall survival. The benefit was consistent across subgroups, and this regimen is now recommended after chemotherapy for germline BRCA1/2 mutation (gBRCA1/2m) carriers with high-risk, HER2-negative early breast cancer. However, the integration of olaparib in the landscape of agents currently available in the post(neo)adjuvant setting-ie, pembrolizumab, abemaciclib, and capecitabine-is challenging, as there are no data suggesting how to select, sequence, and/or combine these therapeutic approaches. Furthermore, it is unclear how to best identify additional patients who could benefit from adjuvant olaparib beyond the original OlympiA criteria. Since it is unlikely that new clinical trials will answer these questions, recommendations for clinical practice can be made through indirect evidence. In this article, we review available data that could help guide treatment decisions for gBRCA1/2m carriers with high-risk, early-stage breast cancer.

Identifying homologous recombination deficiency in breast cancer: genomic instability score distributions differ among breast cancer subtypes.

PURPOSE: A 3-biomarker homologous recombination deficiency (HRD) score is a key component of a currently FDA-approved companion diagnostic assay to identify HRD in patients with ovarian cancer using a threshold score of ≥ 42, though recent studies have explored the utility of a lower threshold (GIS ≥ 33). The present study evaluated whether the ovarian cancer thresholds may also be appropriate for major breast cancer subtypes by comparing the genomic instability score (GIS) distributions of BRCA1/2-deficient estrogen receptor-positive breast cancer (ER + BC) and triple-negative breast cancer (TNBC) to the GIS distribution of BRCA1/2-deficient ovarian cancer. METHODS: Ovarian cancer and breast cancer (ER + BC and TNBC) tumors from ten study cohorts were sequenced to identify pathogenic BRCA1/2 mutations, and GIS was calculated using a previously described algorithm. Pathologic complete response (pCR) to platinum therapy was evaluated in a subset of TNBC samples. For TNBC, a threshold was set and threshold validity was assessed relative to clinical outcomes. RESULTS: A total of 560 ovarian cancer, 805 ER + BC, and 443 TNBC tumors were included. Compared to ovarian cancer, the GIS distribution of BRCA1/2-deficient samples was shifted lower for ER + BC (p = 0.015), but not TNBC (p = 0.35). In the subset of TNBC samples, univariable logistic regression models revealed that GIS status using thresholds of ≥ 42 and ≥ 33 were significant predictors of response to platinum therapy. CONCLUSIONS: This study demonstrated that the GIS thresholds used for ovarian cancer may also be appropriate for TNBC, but not ER + BC. GIS thresholds in TNBC were validated using clinical response data to platinum therapy.

Outcomes after treatment of breast cancer during pregnancy including taxanes and/or granulocyte colony-stimulating factor use: findings from a multi-institutional retrospective analysis.

BACKGROUND: Guidelines support comparable treatment for women diagnosed with breast cancer during pregnancy (PrBC) and nonpregnant women with limited case-specific modifications to ensure maternal-fetal safety. Experience during pregnancy with modern agents, such as taxanes or granulocyte colony-stimulating factors (GCSF), is limited. PATIENTS AND METHODS: We retrospectively identified a multi-institutional cohort of PrBC between 1996 and 2020. Propensity score analyses with multiple imputation for missing variables were applied to determine the associations between chemotherapy exposures during pregnancy, with or without taxanes or GCSF, and a compound maternal-fetal outcome including spontaneous preterm birth, preterm premature rupture of membranes, chorioamnionitis, small for gestational age newborns, congenital malformation, or 5-min Apgar score < 7. RESULTS: Among 139 PrBC pregnancies, 82 (59.0%) were exposed to chemotherapy, including 26 (31.7%) to taxane and 18 (22.0%) to GCSF. Chemotherapy use, in general, and inclusion of taxane and/or GCSF, specifically, increased over time. Pregnancies resulting in live singleton births (n = 123) and exposed to chemotherapy were as likely to reach term as those that were not (59.5% vs. 63.6%, respectively, punadjusted = 0.85). Among women treated with chemotherapy, propensity score-matched odds ratios (OR) for the composite maternal-fetal outcome were not significantly increased with taxane (OR 1.24, 95% CI 0.27-5.72) or GCSF (OR 2.11, 95% confidence interval (CI) 0.48-9.22) with similar effects in multiple imputation and sensitivity models. CONCLUSION: The judicious increased use of taxane chemotherapy and/or growth factor support during pregnancy was not associated with unfavorable short-term maternal-fetal outcomes. While these findings are reassuring, case numbers remain limited and continued surveillance of these patients and progeny is warranted.

Germline genetic testing in breast cancer: Rationale for the testing of all women diagnosed by the age of 60 years and for risk-based testing of those older than 60 years.

Approximately 5% to 10% of women diagnosed with breast cancer will have a pathogenic variant (PV) in a hereditary cancer susceptibility gene, and this has significant implications for the management of these patients and their relatives. Despite the benefits of genetic testing, many eligible patients with breast cancer never undergo testing because of various barriers, including complicated testing criteria such as those from the National Comprehensive Cancer Network (NCCN). In 2019, the American Society of Breast Surgeons (ASBrS) proposed germline genetic testing for all patients with breast cancer to increase the identification of PV carriers. In 2020, a Mayo Clinic study highlighted the limitations of these 2 genetic testing guidelines (NCCN and ASBrS) and proposed a hybrid approach of testing all women diagnosed with breast cancer by the age of 65 years and using NCCN criteria for older patients. This commentary presents an updated analysis of the Mayo Clinic data and discusses the rationale for using the age of 60 years rather than 65 years as the cutoff for this hybrid approach. Using an age at diagnosis of ≤60 or ≤65 years for the universal testing of patients with breast cancer detected more PVs (11.9% [16 of 134] and 15.7% [21 of 134], respectively) in comparison with using the NCCN criteria. Lowering the age for universal testing from 65 to 60 years maintained the sensitivity of detecting a PV at >90% while sparing testing for an additional 10% of women. Compared with the testing of all patients, the hybrid approach would allow 31% of all women with breast cancer to forgo testing and result in fewer variants of uncertain significance identified and, therefore, would decrease the chance of harm from misinterpretation of these variants.

A phase II study of efficacy, toxicity, and the potential impact of genomic alterations on response to eribulin mesylate in combination with trastuzumab and pertuzumab in women with human epidermal growth factor receptor 2 (HER2)+ metastatic breast cancer.

PURPOSE: There are limited data on trastuzumab-pertuzumab (HP)-based treatments beyond the first-line, HER2+ metastatic breast cancer (MBC) setting. We conducted a phase II study of eribulin mesylate, which extends survival in MBC, with HP in patients with previously treated HER2+ MBC to evaluate efficacy, toxicity, and genomic alterations driving therapeutic response. METHODS: After a run-in phase for eribulin dosing, two cohorts were enrolled (Cohort A-no prior pertuzumab; Cohort B-prior pertuzumab). All patients received eribulin 1.4 mg/m2 on days 1, 8 with standard-dose HP on day 1 (21-day cycles). The primary endpoint was objective response rate (ORR). Genomic characterization via whole exome sequencing (WES) was completed on tumor DNA and matched germline DNA from 19 patients. RESULTS: The six-patient run-in established a dose of eribulin 1.4 mg/m2 with HP. Cohorts A and B enrolled 17 and 7 patients, respectively. Accrual stopped early due to an evolving treatment landscape and slow enrollment. The ORR was 26.3% (95% Confidence Interval [CI] 9.2-51.2%) in Cohort A and 0% in Cohort B (95% CI 0-41.0%). WES revealed more frequent alterations in TP53 (p < 0.05, q > 0.05) in patients without clinical benefit (disease control for < 24 weeks) which was not significant after multiple hypothesis correction. CONCLUSION: Eribulin-HP had manageable toxicity and modest clinical activity in patients without prior pertuzumab exposure. This study provides a preliminary landscape of somatic alterations in this patient cohort. Our data add to the literature on how genomic alterations may predict for therapy response/resistance, as we work to individualize choices in a quickly evolving HER2+ MBC treatment landscape. TRIAL REGISTRATION: www.clinicaltrials.gov , NCT01912963. Registered 24 July 2013.

Phase II trial of veliparib and temozolomide in metastatic breast cancer patients with and without BRCA1/2 mutations.

PURPOSE: We evaluated the efficacy and safety of poly-(adenosine diphosphate-ribose) polymerase (PARP) 1 and 2 inhibitor veliparib and temozolomide in metastatic breast cancer patients with and without germline BRCA1/2 mutations. METHODS: In this single-arm phase II trial, patients with metastatic breast cancer received veliparib 30 to 40 mg twice daily on days 1 to 7 with concurrent temozolomide 150 mg/m2 on days 1 to 5 of a 28-day cycle. The primary cohort was unselected for BRCA mutation status, and an expansion cohort enrolled only BRCA1/2 carriers. The primary endpoint was objective response rate (ORR) in each cohort. Secondary endpoints included progression-free survival (PFS), clinical benefit rate (CBR), and evaluation of safety and tolerability. RESULTS: In the primary cohort of 41 unselected patients, which included 9 BRCA mutation carriers, the ORR was 10% and clinical benefit rate at 4 months (CBR) was 27%. In the expansion cohort of 21 BRCA1/2 carriers, the ORR was 14% and CBR was 43%. Among all 30 BRCA1/2 carriers, the ORR was 23% versus 0% among non-carriers. In the subset of BRCA1/2 carriers, the ORR was 32% among platinum-naïve patients versus 9% among platinum-exposed patients. The median PFS was 3.3 months among BRCA1/2 carriers compared to 1.8 months among non-carriers (HR: 0.48, p = 0.006). A longer median PFS of 6.2 months was observed among BRCA1/2 carriers who had no prior platinum therapy. The most common grade 3 and 4 toxicities were thrombocytopenia (32%) and neutropenia (21%) that generally improved with dose modifications. CONCLUSION: Veliparib and temozolomide demonstrated clinical activity in platinum-naïve BRCA-associated metastatic breast cancer with manageable toxicity at doses of veliparib well below the single-agent active dose. Although the study did not meet its primary endpoint in unselected nor BRCA-associated breast cancer, this regimen was further evaluated in the BROCADE 2 study. TRIAL REGISTRATION: NCT01009788 (ClinicalTrials.gov), November 9, 2009.

Chemotherapy-related amenorrhea (CRA) after adjuvant ado-trastuzumab emtansine (T-DM1) compared to paclitaxel in combination with trastuzumab (TH) (TBCRC033: ATEMPT Trial).

PURPOSE: Chemotherapy-related amenorrhea (CRA) is a surrogate for ovarian toxicity and associated risk of infertility and premature menopause. Here, we compare CRA rate with paclitaxel (T)-trastuzumab (H) to that with ado-trastuzumab emtansine (T-DM1). METHODS: Patients with T1N0 HER2 + early-stage breast cancer (eBC) enrolled on the ATEMPT trial and were randomized 3:1 to T-DM1 3.6 mg/kg IV every (q) 3 weeks (w) × 17 vs. T 80 mg/m2 with H IV qw × 12 (4 mg/kg load → 2 mg/kg), followed by H (6 mg/kg IV q3w × 13). Enrollees who self-reported as premenopausal were asked to complete menstrual surveys at baseline and every 6-12 months for 60 months. 18-month CRA (no periods reported during prior 6 months on 18-month survey) was the primary endpoint of this analysis. RESULTS: Of 512 ATEMPT enrollees, 123 who began protocol therapy and answered baseline and at least one follow-up menstrual survey were premenopausal at enrollment. 76 had menstrual data available at 18 months without having received a gonadotropin-releasing hormone agonist or undergone hysterectomy and/or oophorectomy. Median age was 45 (range 23-53) among 18 who had received TH and 46 (range 34-54) among 58 who had received T-DM1. The 18-month rate of CRA was 50% after TH and 24% after T-DM1 (p = 0.045). CONCLUSION: Amenorrhea at 18 months was less likely in recipients of adjuvant T-DM1 than TH. Future studies are needed to understand how T-DM1 impacts risk of infertility and permanent menopause, and to assess amenorrhea rates when T-DM1 is administered after standard HER2-directed chemotherapy regimens.

Alliance A011801 (compassHER2 RD): postneoadjuvant T-DM1 + tucatinib/placebo in patients with residual HER2-positive invasive breast cancer.

This report describes the rationale, purpose and design of A011801 (CompassHER2 RD), an ongoing prospective, multicenter, Phase III randomized trial. Eligible patients in the United States (US) and Canada with high-risk (defined as ER-negative and/or node-positive) HER2-positive (HER2+) residual disease (RD) after a predefined course of neoadjuvant chemotherapy and HER2-directed treatment are randomized 1:1 to adjuvant T-DM1 and placebo, versus T-DM1 and tucatinib. Patients have also received adjuvant radiotherapy and/or endocrine therapy, if indicated per standard of care guidelines. The primary objective of the trial is to determine if the invasive disease-free survival (iDFS) with T-DM1 plus tucatinib is superior to iDFS with T-DM1 plus placebo; other outcomes of interest include overall survival (OS), breast cancer-free survival (BCFS), distant recurrence-free survival (DRFS), brain metastases-free survival (BMFS) and disease-free survival (DFS). Correlative biomarker, quality of life (QoL) and pharmacokinetic (PK) end points are also evaluated.

Lay abstract In this research study (A011801; CompassHER2 RD), patients with early stage HER2-positive breast cancer who already received treatment with chemotherapy and anti-HER2 targeted therapies followed by surgery are mainly enrolled. If cancer is still present in the breast and/or lymph nodes at the time of surgery, there is a higher risk of a recurrence in the future, and enrollment on A011801 is an option. Usually, if there is tumor remaining after chemotherapy and anti-HER2 targeted therapies, the main treatment is the use of an FDA-approved intravenous drug called T-DM1. Additional treatment may also include radiotherapy and/or medications to block the activity of estrogen. The usual treatment approach reduces the likelihood of breast cancer recurring in the future. This study has been performed to answer the following question: Is the combination of T-DM1 and a newer drug tucatinib better than usual treatment with T-DM1 alone at preventing cancer from returning? Study participants will receive treatment with T-DM1 and placebo (a pill that looks like the study drug but contains no medication) or T-DM1 and tucatinib, for up to 14 cycles, unless their breast cancer returns or the side effects become too severe. Research bloods are taken on study along with standard blood work, and we also request a stored tumor sample from the original biopsy and from the breast cancer surgery for research purposes. Optional Quality of Life Questionnaires are also included in the trial. After the study, participants finish T-DM1 and placebo, or T-DM1 and tucatinib, and their doctor will continue to follow their condition with clinic visits every 6 months for 10 years and watch for side effects and for signs of breast cancer recurring. Clinical Trial Registration: NCT04457596 (ClinicalTrials.gov).

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

BACKGROUND: Breast cancer subtypes are associated with distinct metastatic patterns. Whether germline BRCA1/BRCA2 mutation status is independently associated with central nervous system (CNS) relapse, controlling for tumor subtype, is unknown. METHODS: Patients who were treated at Dana-Farber Cancer Institute and diagnosed with a first locoregional recurrence (LRR) or metastasis between 1981 and 2014 were identified using 2 institutional registries: 1) patients treated for recurrent breast cancer and 2) patients who underwent BRCA testing. The frequencies of LRR, sites of metastasis, and breast cancer-specific survival from LRR or metastasis were calculated, and the factors associated with CNS recurrence were evaluated using multivariable logistic regression models. RESULTS: The final study cohort included 30 BRCA1 mutation carriers, 32 BRCA2 mutation carriers, and 270 noncarriers. Most BRCA1 carriers (73%) had triple-negative breast cancer; whereas most BRCA2 carriers (72%) had hormone receptor-positive tumors. BRCA1 carriers frequently experienced lung and distant lymph node metastasis, whereas BRCA2 carriers and noncarriers most often experienced bone metastasis. Although CNS disease occurred frequently in both BRCA1 and BRCA2 carriers (53% BRCA1, 50% BRCA2, 25% noncarriers; P < .001), only BRCA2 mutation (P = .006) was significantly associated with CNS metastasis in multivariable analysis controlling for tumor subtype. BRCA2 mutation (P = .01), triple-negative subtype (P < .001), and the involvement of CNS (P < .001) and other non-CNS distant sites (relative to locoregional recurrence or contralateral disease; P < .001) at presentation of recurrent breast cancer were associated with risk for mortality. CONCLUSIONS: CNS involvement is frequent in women with germline BRCA1/BRCA2 mutations who have metastatic breast cancer. BRCA2 mutation carriers had a significantly higher frequency of CNS metastasis than noncarriers when controlling for breast cancer subtype.

Medical Management of newly diagnosed breast cancer in a BRCA1/2 mutation carrier.

Germline BRCA1/2 mutations may be infrequent in unselected breast cancer population but are concentrated in those with triple-negative breast cancer or high-risk family history. Insight into the biology of BRCA mutation is now allowing a targeted therapeutic approach to these carriers with breast cancer. Functional BRCA genes play a critical role in DNA damage repair. Agents such as platinum salts and poly (ADP-ribose) polymerase (PARP) inhibitors exploit this vulnerability of impaired DNA damage repair mechanism in BRCA mutant cancers to leverage therapeutic benefit. Research has demonstrated improved response rates to platinum salts in BRCA-mutated compared with non-BRCA-mutated breast cancer, particularly in the metastatic setting. Additionally, clinical trials of single-agent PARP inhibitors have shown encouraging response rates and progression-free survival in patients with BRCA1/2-mutated breast cancer. In this review, we summarize the medical management of BRCA-associated breast cancer.

Li-Fraumeni syndrome: not a straightforward diagnosis anymore-the interpretation of pathogenic variants of low allele frequency and the differences between germline PVs, mosaicism, and clonal hematopoiesis.

The introduction of next-generation sequencing has resulted in testing multiple genes simultaneously to identify inherited pathogenic variants (PVs) in cancer susceptibility genes. PVs with low minor allele frequencies (MAFs) (< 25-35%) are highlighted on germline genetic test reports. In this review, we focus on the challenges of interpreting PVs with low MAF in breast cancer patients undergoing germline testing and the implications for management.The clinical implications of a germline PV are substantial. For PV carriers in high-penetrance genes like BRCA1, BRCA2, and TP53, prophylactic mastectomy is often recommended and radiation therapy avoided when possible for those with Li-Fraumeni syndrome (LFS). For germline PV carriers in more moderate-risk genes such as PALB2, ATM, and CHEK2, annual breast MRI is recommended and prophylactic mastectomies considered for those with significant family histories. Detection of PVs in cancer susceptibility genes can also lead to recommendations for other prophylactic surgeries (e.g., salpingo-oophorectomy) and increased surveillance for other cancers. Therefore, recognizing when a PV is somatic rather than germline and distinguishing somatic mosaicism from clonal hematopoiesis (CH) is essential. Mutational events that occur at a post-zygotic stage are somatic and will only be present in tissues derived from the mutated cell, characterizing classic mosaicism. Clonal hematopoiesis is a form of mosaicism restricted to the hematopoietic compartment.Among the genes in multi-gene panels used for germline testing of breast cancer patients, the detection of a PV with low MAF occurs most often in TP53, though has been reported in other breast cancer susceptibility genes. Distinguishing a germline TP53 PV (LFS) from a somatic PV (TP53 mosaicism or CH) has enormous implications for breast cancer patients and their relatives.We review how to evaluate a PV with low MAF. The identification of the PV in another tissue confirms mosaicism. Older age, exposure to chemotherapy, radiation, and tobacco are known risk factors for CH, as is the absence of a LFS-related cancer in the setting of a TP53 PV with low MAF. The ability to recognize and understand the implications of somatic PVs, including somatic mosaicism and CH, enables optimal personalized care of breast cancer patients.

International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation.

BACKGROUND: Women with a BRCA1 or BRCA2 mutation face high risks of breast and ovarian cancer. In the current study, we report on uptake of cancer screening and risk-reduction options in a cohort of BRCA mutation carriers from ten countries over two time periods (1995 to 2008 and 2009 to 2017). METHODS: Eligible subjects were identified from an international database of female BRCA mutation carriers and included women from 59 centres from ten countries. Subjects completed a questionnaire at the time of genetic testing, which included past use of cancer prevention options and screening tests. Biennial follow-up questionnaires were administered. RESULTS: Six-thousand two-hundred and twenty-three women were followed for a mean of 7.5 years. The mean age at last follow-up was 52.1 years (27-96 years) and 42.3% of the women had a prior diagnosis of breast cancer. In all, 27.8% had a prophylactic bilateral mastectomy and  64.7% had a BSO. Screening with breast MRI increased from 70% before 2009 to 81% at or after 2009. There were significant differences in uptake of all options by country. CONCLUSION: For women who received genetic testing more recently, uptake of prophylactic mastectomy and breast MRI is significantly higher than those who received genetic testing more than 10 years ago. However, uptake of both BSO and breast MRI is not optimal, and interventions to increase uptake are needed.

Oncotype DX® Recurrence Score as a Predictor of Response to Neoadjuvant Chemotherapy.

BACKGROUND: The Oncotype DX® assay has been validated in predicting response to adjuvant chemotherapy in breast cancer. Its role in neoadjuvant chemotherapy (NCT) has not been established. METHODS: The National Cancer Database was used to identify all patients with T1-T3, ER-positive, HER2-negative primary invasive breast cancer diagnosed from 2010 to 2015 who had Oncotype DX recurrence scores (RS) and received NCT. RS were classified as low, intermediate, or high. Unadjusted and adjusted regression analyses were performed to determine the association between pathologic complete response (pCR) and RS. RESULTS: A total of 989 patients (mean age, 54.6 years) with available RS who underwent NCT were identified. RS were low in 227 (23.0%) patients, intermediate in 450 (45.5%) patients, and high in 312 (31.5%) patients. Most patients had a T1 (431 [43.6%]) or T2 tumor (451 [45.6%]). Most had N0 disease (757 [76.5%]). Tumor grades were 1 (123 [12.4%]), 2 (517 [52.3%]), or 3 (349 [35.3%]). pCR was achieved by 42 (4.3%) patients. Adjusted multivariable analysis showed a significant association between pCR and high RS (odds ratio 4.87; 95% confidence interval 2.01-11.82). CONCLUSIONS: High Oncotype DX RS was associated with pCR after NCT in this national cohort of ER-positive, HER2-negative patients. Oncotype DX testing could help to identify patients most suited for NCT and should be considered for incorporation into the multidisciplinary decision-making process.

BRCA1/2 testing: therapeutic implications for breast cancer management.

Testing for germline BRCA1/2 mutations has an established predictive role in breast cancer risk assessment. More recently, studies have also identified BRCA1/2 status as clinically relevant in the selection of therapy for patients already diagnosed with breast cancer. Emerging breast and ovarian cancer research indicate that BRCA status predicts responsiveness to platinum-based chemotherapy, as well as to inhibitors of poly(ADP-ribose) polymerase (PARP), owing to the ability of these interventions to inhibit DNA repair pathways. BRCA1/2 mutation testing thus has important and expanding roles in treatment planning for subsets of patients with breast cancer. Recent studies have demonstrated different activity of platinum salts in BRCA-mutated compared with non-BRCA-mutated breast cancer. Furthermore, phase II/III studies of single-agent PARP inhibitors (PARPi) have shown encouraging progression-free survival results in patients with BRCA1/2-mutated breast cancer, which led to the recent approval of olaparib, the first PARPi to be approved in breast cancer. Determining BRCA1/2 mutation status in this breast cancer subgroup could potentially expand treatment options beyond the current standard of taxane and anthracycline-based chemotherapy. Although attempts have been made to develop scoring systems that measure defects in homologous recombination repair pathways to predict response to platinum or PARPi, none have yet made it into clinical use. In this review, we summarise the recent and ongoing preclinical and clinical studies on the treatment of BRCA-associated breast cancer, and discuss efforts to identify other breast cancer patients who may be responsive to therapies effective in BRCA mutation carriers, including platinum-containing chemotherapy and PARPi.

Should We Offer Medication to Reduce Breast Cancer Risk?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

In November 2013, the U.S. Preventive Services Task Force issued a guideline on medications for risk reduction of primary breast cancer in women. Although mammography can detect early cases, it cannot prevent development of breast cancer. Tamoxifen and raloxifene are selective estrogen receptor modulators that have been shown to reduce the risk for estrogen receptor-positive breast cancer and are approved by the U.S. Food and Drug Administration (FDA) for this indication. However, neither medication reduces the risk for estrogen receptor-negative breast cancer or all-cause mortality. The Task Force concluded that postmenopausal women with an estimated 5-year risk for breast cancer of 3% or greater will probably have more net benefit than harm and recommends that clinicians engage in shared, informed decision making about these medications. The American Society of Clinical Oncology issued a practice guideline on use of pharmacologic interventions for breast cancer in 2013. It recommends that women aged 35 years or older at increased risk, defined as a 5-year absolute risk for breast cancer of 1.66% or greater, discuss breast cancer prevention medications with their primary care practitioner. The Society includes the aromatase inhibitor exemestane in addition to tamoxifen and raloxifene as a breast cancer prevention medication, although exemestane is not FDA approved for this indication. Here, an oncologist and an internist discuss how they would balance these recommendations and what they would suggest for an individual patient.

The incidence of leukaemia in women with BRCA1 and BRCA2 mutations: an International Prospective Cohort Study.

BACKGROUND: Germline mutations in BRCA1 and BRCA2 increase the susceptibility to develop breast and ovarian cancers as well as increase the risk of some other cancers. Primary objective was to estimate the risk of leukaemia in BRCA1 and BRCA2 mutation carriers. METHODS: We followed 7243 women with a BRCA1 or a BRCA2 mutation for incident cases of leukaemia. We used the standardised incidence ratio (SIR) to estimate the relative risk of leukaemia, according to mutation and history of breast cancer. RESULTS: We identified five incident cases of leukaemia (two BRCA1, three BRCA2). All five women had a prior history of breast cancer and four had received chemotherapy. The mean time from breast cancer diagnosis to the development of leukaemia was 10.2 years (range 3-18 years). The SIR for BRCA1 carriers was 0.66 (95% CI: 0.11-2.19, P=0.61) and the SIR for BRCA2 carriers was 2.42 (95% CI: 0.61-6.58, P=0.17). The SIR was significantly higher than expected for women with a BRCA2 mutation and breast cancer (SIR=4.76, 95% CI:1.21-12.96, P=0.03), in particular for women who received chemotherapy (SIR=8.11, 2.06-22.07, P=0.007). CONCLUSIONS: We observed an increased risk of leukaemia in women with a BRCA2 mutation who receive chemotherapy for breast cancer.

Immediate breast reconstruction following mastectomy in pregnant women with breast cancer.

BACKGROUND: Surgical management of breast cancer in pregnancy (BCP) requires balancing benefits of therapy with potential risks to the developing fetus. Minimal data describe outcomes after mastectomy with immediate breast reconstruction (IR) in pregnant patients. METHODS: Retrospective review was performed of patients who underwent IR after mastectomy within a BCP cohort. Parameters included intra- and post-operative complications, short-term maternal/fetal outcomes, surgery duration, and delayed reconstruction in non-IR cohort. RESULTS: Of 82 patients with BCP, 29 (35%) had mastectomy during pregnancy: 10 (34%) had IR, 19(66%) did not. All IR utilized tissue expander (TE) placement. Mean gestational age (GA) at IR was 16.2 weeks. Mean surgery duration was 198 min with IR versus 157 min without IR. Those with IR delivered at, or close to, term infants of normal birthweight. No fetal or major obstetrical complications were seen. Post-mastectomy radiation (PMRT) was provided after pregnancy in 2 (20%) patients in the IR cohort and 12 (63%) in the non-IR cohort. All patients in the IR cohort successfully transitioned to permanent implant. CONCLUSIONS: This report represents one of the largest series describing IR during BCP. IR after mastectomy increased surgery duration, but was not associated with adverse obstetrical or fetal outcomes. IR with TE may preserve reconstructive options when PMRT is indicated. J. Surg. Oncol. 2016;114:140-143. © 2016 Wiley Periodicals, Inc.

Breast cancer screening in the era of density notification legislation: summary of 2014 Massachusetts experience and suggestion of an evidence-based management algorithm by multi-disciplinary expert panel.

Stemming from breast density notification legislation in Massachusetts effective 2015, we sought to develop a collaborative evidence-based approach to density notification that could be used by practitioners across the state. Our goal was to develop an evidence-based consensus management algorithm to help patients and health care providers follow best practices to implement a coordinated, evidence-based, cost-effective, sustainable practice and to standardize care in recommendations for supplemental screening. We formed the Massachusetts Breast Risk Education and Assessment Task Force (MA-BREAST) a multi-institutional, multi-disciplinary panel of expert radiologists, surgeons, primary care physicians, and oncologists to develop a collaborative approach to density notification legislation. Using evidence-based data from the Institute for Clinical and Economic Review, the Cochrane review, National Comprehensive Cancer Network guidelines, American Cancer Society recommendations, and American College of Radiology appropriateness criteria, the group collaboratively developed an evidence-based best-practices algorithm. The expert consensus algorithm uses breast density as one element in the risk stratification to determine the need for supplemental screening. Women with dense breasts and otherwise low risk (<15% lifetime risk), do not routinely require supplemental screening per the expert consensus. Women of high risk (>20% lifetime) should consider supplemental screening MRI in addition to routine mammography regardless of breast density. We report the development of the multi-disciplinary collaborative approach to density notification. We propose a risk stratification algorithm to assess personal level of risk to determine the need for supplemental screening for an individual woman.

Sentinel lymph node biopsy in pregnant women with breast cancer.

BACKGROUND: Sentinel lymph node biopsy (SNB) in pregnant women with breast cancer is uncommonly pursued given concern for fetal harm. This study evaluated efficacy and safety outcomes in pregnant breast cancer patients undergoing SNB. METHODS: Patients who underwent SNB while pregnant were identified from a retrospective parent cohort of women diagnosed with breast cancer during pregnancy. Chart review was performed to tabulate patient/tumor characteristics, method/outcome of SNB, and short-term maternal/fetal outcomes. RESULTS: Within a cohort of 81, 47 clinically node-negative patients had surgery while pregnant: 25 (53.2 %) SNB, 20 (42.6 %) upfront axillary lymph node dissection, and 2 (4.3 %) no lymph node surgery. Of SNB patients, 8, 9, and 8 had SNB in the first, second, and third trimesters, respectively. 99 m-Technetium (99-Tc) alone was used in 16 patients, methylene blue dye alone in 7 patients, and 2 patients had unknown mapping method. Mapping was successful in all patients. There were no SNB-associated complications. At a median of 2.5 years from diagnosis, there was one locoregional recurrence, one new primary contralateral tumor, three distant recurrences, and one breast cancer death. Among patients who underwent SNB, there were 25 liveborn infants, of whom 24 were healthy, and 1 had cleft palate (in the setting of other maternal risk factors). CONCLUSIONS: SNB in pregnant breast cancer patients appears to be safe and accurate using either methylene blue or 99-Tc. This is one of the largest reported experiences of SNB during pregnancy; however, numbers remain limited. SNB rates in this cohort were lower than in non-pregnant breast cancer patients.