Risk Of Contralateral Breast Cancer Research Articles

Contralateral Prophylactic Mastectomy in Patients with Breast Cancer.

Introduction: The rate of contralateral prophylactic mastectomy (CPM) increased within the recent years. The main reasons are: genetic testing, availability of breast reconstruction, more often use of preoperative breast MRI, improvement of postoperative aesthetic results and reimbursement of breast reconstruction. The purpose of this study was to analyze the indication of CPM, it's evolution and the surgical techniques used for this type of surgery. Materials and methods: This prospective study enrolled patients with unilateral breast cancer for which conservative treatment was not an option and underwent CPM concomitant with therapeutic mastectomy, using different techniques, followed by immediate breast reconstruction using alloplastic materials. Results: A total of 45 patients with unilateral breast cancer underwent therapeutic mastectomy and CPM followed by immediate breast reconstruction, between January 2015-December 2020. The mean age was 43.5 years, 64,44% patients had stage I and II breast cancer and 22,22% were triplenegative. The indications for CPM were: pathogenic mutation of BRCA or of other genes associated with high risk of breast cancer, strong family history, suspicious findings on breast MRI, extended micro-calcifications, dense breasts, and extreme anxiety. Conclusions: A growing rate of bilateral mastectomy for unilateral breast cancer was observed. Availability of immediate breast reconstruction and reimbursement plays an important role for patients in choosing CPM. Factors associated with CPM include: young age, pathogenic BRCA mutation, significant family history and triple-negative disease. The rate of immediate postoperative complications was low. CPM is a valid option to reduce the risk of contralateral breast cancer and to achieve a good aesthetic outcome for patients with unilateral breast cancer with high risk of contralateral breast cancer.

Risk Factors and Specific Cancer Types of Second Primary Malignancies in Patients With Breast Cancer Receiving Adjuvant Radiotherapy: A Case–Control Cohort Study Based on the SEER Database

Patients with breast cancer can survive and live a long, cancer-free life; however, late complications of treatment, such as second primary malignancies (SPMs), have emerged as a competing cause of death and morbidity. We conducted a long-term population-based cohort study to identify the risk factors for SPMs and specific secondary cancer types after various latency periods of irradiated breast cancer. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (95% CI) for independent risk factors for SPM. We also calculated the HR of each specific cancer type and the latency time to specific SPMs. The risk of SPM was statistically significantly higher in patients with adjuvant RT than in patients without adjuvant RT (adjusted HR [aHR]: 1.105, 95% CI: 1.013-1.206). Compared with the control group, the case group had significantly increased risks of contralateral breast cancer (aHR: 1.268, 95% CI: 1.112-1.445), lung cancer (aHR: 1.218, 95% CI: 1.049-1.565), and urinary system cancer (aHR: 1.702, 95% CI: 1.140-2.543). Adjuvant RT for breast cancer increases the risk of SPM. Contralateral breast cancer, lung cancer, and bladder cancer were significant SPMs after breast RT, although the cumulative risk of SPM was low, at approximately 6, 10, and 13 cancers per 1000 women with irradiated breasts at latency periods of 5, 10, and 15 years, respectively, after breast RT.

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Background: Chronic encapsulated seroma following breast cancer surgery is a rare entity, and management is challenging. We present clinical and pathologic findings in a patient with extensive history of bilateral refractory breast seroma successfully treated with capsulectomy. Case presentation: A 71-year-old woman with previous early BRCA2 associated, node-negative breast cancer, developed late onset seroma following endocrine therapy, unilateral breast-conserving surgery, and completion of adjuvant radiotherapy. Non-simultaneous bilateral mastectomy was later performed to treat infection and reduce risk of contralateral breast cancer. Each surgery was followed by chronic seroma. After six years of ineffective treatment attempts with repeated aspirations, the patient successfully underwent bilateral capsulectomy. She remains seroma-free nine months from time of capsulectomy. Conclusion: This is the first report of late onset bilateral encapsulated breast seroma following mastectomy without axillary dissection. When managing breast seroma refractory to conventional treatment encapsulated seroma and prompt capsulectomy should be considered.

Detection of Malignant lesion in Contralateral Breast in Newly Diagnosed Patients of Unilateral Carcinoma Breast on MRI

Background: Women having unilateral breast cancer have added risk of contralateral breast cancer with an incidence of 1-5% synchronous cancer. There is also increased risk of metachronous cancer in contralateral breast . Female patients with bilateral breast cancer have grave prognosis in comparison to those with unilateral breast cancer. MRI breast is used to assess the multifocality and multicentricity of tumour. Objective: To determine the diagnostic performance of MRI in detecting malignant lesion in contralateral breast in newly diagnosed patients of unilateral carcinoma breast.Material and Methods: In this study total 150 newly diagnosed patients of unilateral breast cancer with normal mammographic and clinical examination of other breast were included. Study was conducted in Radiology department, Hayatabad Medical Complex Peshawar from Jan 2017 to March 2020. MRI scan of normal breast was done on a 1.5 Tesla magnet with multi-channel breast coil. For evaluating the breast lesions, administration of IV contrast and high spatial resolution is necessary .The malignant lesions of breast found on MRI were confirmed histo-pathologically. Results: In 5 out of total 150 women included in study, MRI detected occult breast cancer in the opposite breast in whom clinical examination and mammography was normal (3.3%). 18 women (12.5 %) out of total 150 with positive findings on MRI underwent biopsy, and 5 specimens turned out to be carcinoma (27%). Conclusion: MRI is very useful and helpful to detect occult malignancy in opposite breast which are not detected clinically or by mammography at the time of the initial diagnosis of carcinoma breast.

Bilateral prophylactic mastectomy as an option for prevention of contralateral breast cancer

The article discusses the risk factors for contralateral breast cancer and the role of prophylactic bimastectomy in reducing these risks. Breast cancer is the most frequent cancer among women. Several strategies have been implemented to reduce the risk of occurrence and recurrence of breast cancer: lifestyle changes, early detection through diagnosis and screening, chemotherapy, and surgery.Prophylactic mastectomy is one of the growing strategies to reduce the risk of breast cancer. Evidence suggests that the incidence of prophylactic bimastectomy in patients with unilateral breast cancer is steadily increasing, due not only to cancer case but also with requirements in women to modern quality of life. For women who choose or need to undergo a therapeutic mastectomy, removal of the contralateral breast is often discussed. Although the risk of contralateral breast cancer is relatively low for patients without hereditary genetic mutations with an established primary diagnosis of breast cancer, the total number of women who are at risk of developing contralateral breast cancer has increased markedly over the past few decades. Thus, among the risk factors influencing the occurrence of cancer in the contralateral healthy breast are young women with breast cancer, genetic mutation carriers, strong family history, ductal non-invasive cancer, tumour characteristics, which are indication to bilateral prophylactic mastectomy with immediate breast reconstruction.However, at the present stage of development oncoplastic and reconstructive breast cancer surgery, in the leading position one of the indications for prophylactic contralateral subcutaneous mastectomy with immediate breast reconstruction – is the patient's desire to preserve aesthetics and femininity. The level of satisfaction among women with bilateral mastectomy and breast reconstruction is higher than in women with unilateral mastectomy and reconstruction. Improvement of reconstructive and surgical techniques for performing contralateral prophylactic mastectomy provides the best aesthetic result among patients. Therefore, the present data requires a more detailed study of this issue and approval in the scientific community.

Contralateral breast cancer and tumor recurrence in BRCA1/2 carriers and non-carriers at a high risk of hereditary breast cancer after bilateral mastectomy

IntroductionContralateral prophylactic mastectomy (CPM) has been reported to reduce risk of contralateral breast cancer (CBC) by at least 90%. In addition, BRCA carriers present higher risk of ipsilateral recurrence and a second primary tumor.The aim is to evaluate risk of CBC and recurrence and to analyze predictive factors in BRCA1/2 mutation carriers and non-carriers at high-risk of hereditary breast cancer patients. MethodsRetrospective observational study. 46 patients underwent bilateral mastectomy during 2004–2018. ResultsCohort comprised of 9 patients BRCA1, 12 BRCA2 and 25 at high-risk without mutation. Median follow-up was 79 months. 16 patients recently diagnosed and 30 previously treated for breast cancer who underwent CPM a second time (because of later detection of BRCA mutation in 10 cases). The external lateral incision was the most frequent surgical technique. In all patients, immediate reconstruction was performed.In CPM pieces, 4 in situ carcinoma, 3 invasive and 1 atypical hyperplasia were found. The incidence of occult contralateral cancer was 15.2%. Recurrence was observed in 5 patients a mean of 21.2 months after surgery. DFSD was 83.74 months and OS 84.33 months. Regression models identified BRCA1/2 mutation and high risk without mutation as significant occult tumor predictive factors while tumor size≥2cm was predictive of recurrence. ConclusionsIn our series we found a 10.8% recurrence despite CPM and 7 patients (15.2%) would have developed a CBC in subsequent years.

Contralateral breast cancer risk and endocrine therapy use in patients with ductal carcinoma in situ treated with unilateral mastectomy in the modern era

BackgroundIn patients with ductal carcinoma in situ (DCIS), the risk of developing contralateral breast cancer (CBC) and the role of adjuvant endocrine therapy (ET) in decreasing CBC risk is not well understood. MethodsA retrospective review was performed on patients with DCIS who underwent a unilateral mastectomy (UM) from 2000 to 2010. CBC incidence, time to CBC and disease free survival were evaluated for women who took ET versus those who did not. Results176 patients underwent a UM for DCIS, 72% were ER positive and 16% of patients took ET. At a median of 12 year follow up, 15 patients experienced CBC. Women over 63 years had highest incidence of CBC. CBC risk was not different between those who took ET versus those who did not. ConclusionThe overall incidence of CBC was 9% in our DCIS cohort and was not significantly different among patients who took ET versus those who did not.

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

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

14P BRCA mutation and clinical outcomes in breast cancer focusing on survivals and failure patterns: A long-term follow-up study of Koreans

The purpose of this study was to evaluate the effect of BRCA mutation on survival and recurrence rate, focusing on risk of ipsilateral recurrence and contralateral breast cancer in breast cancer patients who underwent genetic screening for BRCA1/2 mutation and were treated at Samsung Medical Center. 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 January 1, 2000 and December 31, 2010. Ultimately, clinical outcomes of 273 patients were analyzed. The median follow-up duration was 102 months (range, 1 to 220 months). BRCA1/2-mutated tumors had 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, BRCA1/2-mutated tumors showed higher incidence of contralateral breast cancer than 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 having BRCA mutation showed inferior DFS compared to those without BRCA mutation. BRCA mutation status is a strong predictor of recurrence in contralateral breast. Strategies such as prophylactic treatment and active surveillance should be discussed with breast cancer patients who have BRCA mutations.

Incidence of contralateral and ipsilateral breast cancers and prognosis in BRCA1/2 pathogenic variant carriers based on the Japanese HBOC Consortium registration

This study aimed to clarify the breast cancer prognosis in Japanese patients with BRCA1/2 pathogenic variant. We analyzed 2235 women with breast cancer who underwent BRCA1/2 genetic testing between 1996 and 2018 using data from the Japanese hereditary breast and ovarian cancer syndrome registry. The cumulative risk for contralateral and ipsilateral breast cancers and time to death since the first breast cancer were stratified based on the BRCA1/2 variant status. The median follow-up was 3.0 years (0.1-34.1 years) after the first breast cancer. The annual average risks of contralateral breast cancer in BRCA1 and BRCA2 and non-BRCA1/2 pathogenic variant carriers were 4.0%, 2.9%, and 1.9%, respectively (P = 0.001). The annual average risks of ipsilateral breast cancer in the three groups were 2.7%, 1.4%, and 1.1%, respectively (P = 0.06). BRCA1 pathogenic variant carriers had significantly higher risks of contralateral (hazard ratio 1.91, P < 0.001) and ipsilateral (hazard ratio 2.00, P = 0.02) breast cancers than non-BRCA1/2 pathogenic variant carriers. The time to death by the BRCA1/2 variant status was not significantly difference (P = 0.28). The prognosis of breast cancer patients who received standard treatment was comparable regardless of the BRCA1/2 variant status.

Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk

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

196 Poster - Risk of contralateral breast cancer and ovarian cancer in BRCA1 founder mutation (5382insC or 4154delA) carriers with primary breast cancer

196 Poster - Risk of contralateral breast cancer and ovarian cancer in BRCA1 founder mutation (5382insC or 4154delA) carriers with primary breast cancer

16 Oral - Contralateral breast cancer in patients with ductal carcinoma in situ and invasive breast cancer in the Netherlands

Background: The cumulative incidence of invasive contralateral breast cancer (CBC) for patients with first invasive breast cancer (BC) is approximately 0.4% per year. Less is known about CBC risk in patients with ductal carcinoma in situ (DCIS). We aimed to assess the CBC risk in patients with first DCIS compared to those with invasive BC, taking age, screening period, and (neo) adjuvant systemic therapy into account.

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.

Rapid Genetic Testing for BRCA1 and BRCA2 Mutations at the Time of Breast Cancer Diagnosis: An Observational Study.

This study aimed to evaluate the impact of rapid genetic testing (RGT) for BRCA1 and BRCA2 at the time of breast cancer diagnosis on treatment choices. Bilateral mastectomy for the treatment of breast cancer in women with a BRCA1 or BRCA2 mutation offers a reduction in the risk of contralateral breast cancer. It is unclear whether offering RGT at the time of breast cancer diagnosis has an impact on women's surgical decision-making. Women with breast cancer diagnosed between June 2013 and May 2018 were recruited from four academic health sciences centers in Toronto, Canada. The participants completed a questionnaire before genetic testing, then one week and one year after disclosure of the genetic test result. Before surgery, RGT was performed. Diagnostic, pathologic, and treatment data were compared between those with and those without a BRCA mutation. The study enrolled 1007 women who consented to RGT. The mean age of the participants was 46.3years, and the median time to result disclosure was 10days. A BRCA mutation was found in 6% of the women. The women with a BRCA mutation were significantly more likely to elect for bilateral mastectomy than the women without a BRCA mutation (p < 0.0001). Of the BRCA-positive patients, 95.7% reported that they used their genetic test result to make a surgical decision. The women provided with RGT at the time of breast cancer diagnosis use the genetic information to make treatment decisions, and the majority of those identified with a BRCA mutation elect for a bilateral mastectomy.

A case-control study of the joint effect of reproductive factors and radiation treatment for first breast cancer and risk of contralateral breast cancer in the WECARE study

ObjectiveTo examined the impact of reproductive factors on the relationship between radiation treatment (RT) for a first breast cancer and risk of contralateral breast cancer (CBC). MethodsThe Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study is a multi-center, population-based case-control study where cases are women with asynchronous CBC (N = 1521) and controls are women with unilateral breast cancer (N = 2211). Rate ratios (RR) and 95% confidence intervals (CI) were estimated using conditional logistic regression to assess the independent and joint effects of RT (ever/never and location-specific stray radiation dose to the contralateral breast [0, >0-<1Gy, ≥1Gy]) and reproductive factors (e.g., parity). ResultsNulliparous women treated with RT (≥1Gy dose) were at increased risk of CBC compared with nulliparous women not treated with RT, although this relationship did not reach statistical significance (RR = 1.34, 95% CI 0.87, 2.07). Women treated with RT who had an interval pregnancy (i.e., pregnancy after first diagnosis and before second diagnosis [in cases]/reference date [in controls]) had an increased risk of CBC compared with those who had an interval pregnancy with no RT (RR = 4.60, 95% CI 1.16, 18.28). This was most apparent for women with higher radiation doses to the contralateral breast. ConclusionAmong young female survivors of breast cancer, we found some evidence suggesting that having an interval pregnancy could increase a woman’s risk of CBC following RT for a first breast cancer. While sampling variability precludes strong interpretations, these findings suggest a role for pregnancy and hormonal factors in radiation-associated CBC.

Abstract 5749: The association between physical health-related quality of life, physical functioning and risk of contralateral breast cancer

Abstract Background: Physical limitations and disability among older cancer patients can lead to suboptimal treatment and surveillance for secondary cancers. Our objective was to evaluate the effects of poor physical health-related quality of life (PQOL) and physical functioning (PF) on contralateral breast cancer (CBC) risk among older women diagnosed with unilateral breast cancer (UBC). Methods: We performed a nested case-control study within a cohort from the Surveillance, Epidemiology and End Results Medicare Health Outcomes Survey (MHOS) database. Women were required to have first primary UBC without prophylactic contralateral mastectomy. Among 2,938 women ages 65 years and older with stages I-III UBC between 1997 and 2011, we identified 100 subsequent CBC cases and 915 controls using incidence density sampling without replacement matched on age, race, and quarter-year of diagnosis. PQOL and PF were determined from survey responses to the Medical Outcomes Trust Short Form 36 component scores. Conditional logistic regression models were used to estimate relative risks (RR) and 95% confidence intervals (CI) for metachronous CBC. Results: Cases and controls were similar with respect to comorbidities, stage, surgery and radiation treatments but differed by hormone receptor status (ER/PR-negative, cases 23% and controls 11%). Cases had lower mean PQOL (-1.8; 95% CI -4.3, 0.7) and PF (-2.2, 95% CI -4.9, 0.5) component scores, but these differences were not statistically significant. In multivariable models, estimates suggest increased CBC risk for women in the lowest quartile of PQOL compared to those in the upper quartile (RR=1.8; 95% CI 0.8, 4.3). Compared to women in the upper quartile of physical functioning scores, women in the lower three quartiles had a 2.6-fold (95% CI 1.2, 5.9) increased risk of CBC. Conclusions: Our findings indicate that low physical health-related quality of life is common among older women diagnosed with breast cancer, and poor physical functioning is related to risk of CBC. Efforts to understand and minimize declines in physical functioning post-breast cancer diagnosis may help optimize treatment strategies to reduce the risk of this adverse outcome. Citation Format: Nita Mukand, Nadia Nabulsi, Ali Alobaidi, Alemseged Asfaw, Brian C. Chiu, Naomi Y. Ko, Gregory S. Calip. The association between physical health-related quality of life, physical functioning and risk of contralateral breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5749.

Evidence for Increased Susceptibility to Breast Cancer From Exposure to Ionizing Radiation Due to a Familial History of Breast Cancer: Results From the Swedish Hemangioma Cohort.

Women with a history of breast cancer among family members are at increased risk for breast cancer. However, it is unknown whether a familial breast cancer history (FBCH) also increases individual susceptibility to breast cancer from radiation exposure. In this cohort study, 17,200 female Swedish hemangioma patients with 1,079 breast cancer cases diagnosed between 1958 and 2013, exposed to ionizing radiation in infancy, were linked to their first-degree relatives. The association between FBCH and radiation-induced breast cancer risk was assessed. Further, the relevance for breast cancer radiotherapy and mammography screening was evaluated. On average, the radiation-induced excess relative risk and excess absolute risk of breast cancer at age 50 years were 0.51 Gy−1 (95% confidence interval (CI): 0.33, 0.71) and 10.8 cases/10,000 person-years/Gy (95% CI: 7.0, 14.6), respectively. Radiation risk was higher by a factor of 2.7 (95% CI: 1.0, 4.8; P = 0.05) if 1 first-degree relative was affected by breast cancer. For whole-breast standard radiotherapy at age 40 years with a contralateral breast dose of 0.72 Gy, the 20-year radiation-related excess risk of contralateral breast cancer was estimated to increase from 0.6% for women without FBCH to 1.7% for women with FBCH. In a biennial mammography screening program at ages 40–74 years, radiation risk up to age 80 years would increase from 0.11% for women without FBCH to 0.29% for women with FBCH.

Contralateral Risk-Reducing Mastectomy in Breast Cancer Patients Who Undergo Multigene Panel Testing.

An increasing number of breast cancer patients are undergoing expanded genetic testing and are being identified as germline mutation carriers. We sought to determine rates of contralateral risk-reducing mastectomy (CRRM) in patients with various germline mutations. All women ≥ 18years of age with unilateral breast cancer who underwent multigene panel testing between January 1, 2014 and August 1, 2019 at our academic institution were identified. Demographic, tumor, and treatment variables were identified from the medical record. Multivariable analyses were performed to compare factors associated with performance of CRRM. We identified 1613 patients, of whom 28.1% had a pathogenic variant and 40.1% had variants of uncertain significance (VUS). Overall, 420 patients (26.0%) underwent a CRRM. On multivariable analysis, factors associated with CRRM included age < 50years (OR 3.8, 95% CI 3.0, 5.0), race (OR 0.5, 95% CI 0.3, 0.7 and OR 0.4, 95% CI 0.2, 0.7 for Black and Asian women, respectively, versus White women), and the presence of any germline mutation or VUS (OR 13.2, 95% CI 8.7, 20.2 for BRCA1/2; OR 3.9, 95% CI 2.7, 5.8 for non-BRCA germline mutation; and OR 1.8, 95% CI 1.3, 2.6 for VUS). In breast cancer patients who undergo multigene panel testing, a sizeable number of women with pathogenic non-BRCA germline findings are opting for CRRM. Given that the risk of contralateral breast cancer in women with most pathogenic mutations other than BRCA1/2 remains poorly characterized, these data have implications for risk counseling and for ascertaining the true risks of contralateral breast cancer in this population.

Cáncer de mama contralateral y recurrencia en portadoras BRCA1/2 y no portadoras con alto riesgo de cáncer de mama hereditario tras mastectomía bilateral

IntroductionContralateral prophylactic mastectomy (CPM) has been reported to reduce risk of contralateral breast cancer (CBC) by at least 90%.In addition, BRCA carriers presents higher risk of ipsilateral recurrence and a second primary tumor.The aim is to evaluate risk of CBC and recurrence and to analyze predictive factors in BRCA1/2 mutation carriers and non-carriers at high-risk of hereditary breast cancer patients. MethodsRetrospective observational study. 46 patients underwent bilateral mastectomy during 2004-2018. ResultsCohort comprised 9 patients BRCA1,12 BRCA2 and 25 at high-risk without mutation. Median follow-up 79 months. 16 patients recently diagnosed and 30 previously treated by breast cancer whom underwent CPM at second time (because of later detection of BRCA mutation in 10 cases). The external lateral incision was most frequent surgical technique. In all patients immediate reconstruction was performed.In CPM pieces, 4 in situ carcinoma, 3 invasive and 1 atypical hyperplasia were found. The incidence of occult contralateral cancer was 15.2%. Recurrence was observed in 5 patients a media of 21.2 months after surgery. FSD was 83.74 months and OS 84.33 months. Regression models identified BRCA1/2 mutation and high risk without mutation as significant occult tumor predictive factors while tumor size≥2cm was predictive of recurrence. ConclusionsIn our series we found a10.8% recurrence despite CPM and 7 patients (15.2%) would have developed a CBC in subsequent years.