Assessment of the effect of the American Society of Breast Surgery guidelines on contralateral prophylactic mastectomy rates for unilateral breast cancer.

BACKGROUND: In July 2016, the American Society of Breast Surgeons published guidelines discouraging contralateral prophylactic mastectomy for average-risk women with unilateral breast cancer. We incorporated these into practice with structured patient counseling and aimed to assess the effect of this initiative on contralateral prophylactic mastectomy rates. METHODS: We evaluated female patients with unilateral breast cancer undergoing mastectomy at our institution from January 2011 to November 2022. Variables associated with contralateral prophylactic mastectomy and trends over time were analyzed using the Wilcoxon rank sum test or χ2 analysis as appropriate. RESULTS: Among 3,208 patients, (median age 54 years) 1,366 (43%) had a unilateral mastectomy, and 1,842 (57%) also had a concomitant contralateral prophylactic mastectomy. Across all patients, contralateral prophylactic mastectomy rates significantly decreased post-implementation from 2017 to 2019 (55%) vs 2015 to 2016 (62%) (P = .01) but increased from 2020 to 2022 (61%). Immediate breast reconstruction rate was 70% overall (81% with contralateral prophylactic mastectomy and 56% without contralateral prophylactic mastectomy, P < .001). Younger age, White race, mutation status, and earlier stage were also associated with contralateral prophylactic mastectomy. Genetic testing increased from 27% pre-guideline to 74% 2020 to 2022, as did the proportion of patients with a pathogenic variant (4% pre-guideline vs 11% from 2020-2022, P < .001), of whom 91% had a contralateral prophylactic mastectomy. Among tested patients without a pathogenic variant and patients not tested, contralateral prophylactic mastectomy rates declined from 78% to 67% and 48% to 38% pre -and post-guidelines, respectively, P < .001. CONCLUSION: Implementation of specific patient counseling was effective in decreasing contralateral prophylactic mastectomy rates. While recognizing that patient choice plays a significant role in the decision for contralateral prophylactic mastectomy, further educational efforts are warranted to affect contralateral prophylactic mastectomy rates, particularly in the setting of negative genetic testing.

Contralateral prophylactic mastectomy rate and predictive factors among patients with breast cancer who underwent multigene panel testing for hereditary cancer.

Although multigene panel testing is increasingly common in patients with cancer, the relationship between its use among breast cancer patients with non-BRCA mutations or variants of uncertain significance (VUS) and disease management decisions has not been well described. This study evaluated the rate and predictive factors of CPM patients who underwent multigene panel testing. Three hundred and fourteen patients with breast cancer who underwent multigene panel testing between 2014 and 2017 were included in the analysis. Of the 314 patients, 70 elected CPM. Election of CPM by gene status was as follows: BRCA carriers (42.3%), non-BRCA carriers (30.1%), and VUS (10.6%). CPM election rates did not differ between non-BRCA carriers and BRCA carriers (P = 0.6205). Among non-BRCA carriers, negative hormone receptor status was associated with CPM (P = 0.0115). For those with a VUS, hormone receptor status was not associated with CPM (P = 0.1879). Although the rate of CPM between BRCA carriers and non-BRCA carriers was not significantly different, the predictors of CPM were different in each group. Our analyses shed the light on the increasing use of CPM among patients who are non-BRCA carriers as well those with a VUS. Our study elucidates the differing predictive factors of CPM election among BRCA carriers, non-BRCA carries, and those with a VUS. Our findings reveal the need for providers to be cognizant that non-BRCA genes and VUS drive women to elect CPM despite the lack of data for contralateral breast cancer risk associated with these genes.

Risk-reducing mastectomy for the prevention of primary breast cancer.

BACKGROUND: Recent progress in understanding the genetic basis of breast cancer and widely publicized reports of celebrities undergoing risk-reducing mastectomy (RRM) have increased interest in RRM as a method of preventing breast cancer. This is an update of a Cochrane Review first published in 2004 and previously updated in 2006 and 2010. OBJECTIVES: (i) To determine whether risk-reducing mastectomy reduces death rates from any cause in women who have never had breast cancer and in women who have a history of breast cancer in one breast, and (ii) to examine the effect of risk-reducing mastectomy on other endpoints, including breast cancer incidence, breast cancer mortality, disease-free survival, physical morbidity, and psychosocial outcomes. SEARCH METHODS: For this Review update, we searched Cochrane Breast Cancer's Specialized Register, MEDLINE, Embase and the WHO International Clinical Trials Registry Platform (ICTRP) on 9 July 2016. We included studies in English. SELECTION CRITERIA: Participants included women at risk for breast cancer in at least one breast. Interventions included all types of mastectomy performed for the purpose of preventing breast cancer. DATA COLLECTION AND ANALYSIS: At least two review authors independently abstracted data from each report. We summarized data descriptively; quantitative meta-analysis was not feasible due to heterogeneity of study designs and insufficient reporting. We analyzed data separately for bilateral risk-reducing mastectomy (BRRM) and contralateral risk-reducing mastectomy (CRRM). Four review authors assessed the methodological quality to determine whether or not the methods used sufficiently minimized selection bias, performance bias, detection bias, and attrition bias. MAIN RESULTS: All 61 included studies were observational studies with some methodological limitations; randomized trials were absent. The studies presented data on 15,077 women with a wide range of risk factors for breast cancer, who underwent RRM.Twenty-one BRRM studies looking at the incidence of breast cancer or disease-specific mortality, or both, reported reductions after BRRM, particularly for those women with BRCA1/2 mutations. Twenty-six CRRM studies consistently reported reductions in incidence of contralateral breast cancer but were inconsistent about improvements in disease-specific survival. Seven studies attempted to control for multiple differences between intervention groups and showed no overall survival advantage for CRRM. Another study showed significantly improved survival following CRRM, but after adjusting for bilateral risk-reducing salpingo-oophorectomy (BRRSO), the CRRM effect on all-cause mortality was no longer significant.Twenty studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have RRM but greater variation in satisfaction with cosmetic results. Worry over breast cancer was significantly reduced after BRRM when compared both to baseline worry levels and to the groups who opted for surveillance rather than BRRM, but there was diminished satisfaction with body image and sexual feelings.Seventeen case series reporting on adverse events from RRM with or without reconstruction reported rates of unanticipated reoperations from 4% in those without reconstruction to 64% in participants with reconstruction.In women who have had cancer in one breast, removing the other breast may reduce the incidence of cancer in that other breast, but there is insufficient evidence that this improves survival because of the continuing risk of recurrence or metastases from the original cancer. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention, when considering RRM. AUTHORS' CONCLUSIONS: While published observational studies demonstrated that BRRM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies are suggested. BRRM should be considered only among those at high risk of disease, for example, BRCA1/2 carriers. CRRM was shown to reduce the incidence of contralateral breast cancer, but there is insufficient evidence that CRRM improves survival, and studies that control for multiple confounding variables are recommended. It is possible that selection bias in terms of healthier, younger women being recommended for or choosing CRRM produces better overall survival numbers for CRRM. Given the number of women who may be over-treated with BRRM/CRRM, it is critical that women and clinicians understand the true risk for each individual woman before considering surgery. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention when considering RRM.

Mastectomy patterns, but not rates, are changing in the treatment of early breast cancer. Experience of a single European institution on 2315 consecutive patients.

BACKGROUND: Recent literature reports that rates of mastectomy are increasing in early breast cancer. However, data from European institutions are limited and revealed conflicting results. We report on 15-year trends of mastectomy, mastectomy plus immediate reconstruction and contralateral prophylactic mastectomy (CPM) at an academic institution. METHODS: We identified women diagnosed with unilateral early breast cancer at stage 0-IIa, with tumour size ≤ 4 cm, between 2002 and 2016. Trends were assessed using the Cochrane-Armitage test. Multivariable logistic regression was used to identify factors associated with receipt of mastectomy plus immediate reconstruction. RESULTS: A total of 2315 patients were identified. Of them, 65.7% underwent breast conserving surgery (BCS), while 34.3% underwent mastectomy as upfront surgery. Two point four per cent also received CPM. Immediate reconstruction was performed in 36.0% of patients receiving mastectomy. There was no change in trends of mastectomy over the 15 years studied (p = 0.69), as well as in trends of patients undergoing CPM (p = 0.44). In contrast, rates of immediate reconstruction rose significantly over the study period (from 12.2% in 2002 to 62.7% in 2016, p < 0.0001). Women were more likely to receive mastectomy plus immediate reconstruction if they were aged 50 years or younger, or had tumours larger than 2 cm, or had non-invasive carcinoma. CONCLUSIONS: Our study suggests that rates of both mastectomy and CPM in early breast cancer are not increasing, while use of immediate reconstruction is on the rise.

Benefits and risks of contralateral prophylactic mastectomy in women undergoing treatment for sporadic unilateral breast cancer: a decision analysis.

The rate of contralateral prophylactic mastectomy (CPM) is rising rapidly, despite limited evidence about the procedure's relative benefits and harms. The objective of this study is to examine the impact of CPM on life expectancy (LE) and quality-adjusted life expectancy (QALE) in women with sporadic unilateral breast cancer. A Markov model was developed to compare 18 hypothetical cohorts of 45-year-old women with newly diagnosed unilateral, sporadic breast cancer treated with or without CPM. The probability of developing distant metastases by American Joint Committee on Cancer stage and molecular subtype was derived from British Columbia Cancer Agency data. Additional model parameters were identified from the medical literature. Sensitivity analyses were performed to examine the impact of plausible variations in key model parameters on results. CPM improved LE in all cohorts (range 0.06-0.54 years). Stage had more effect on LE than subtype (stage I mean, 0.44 years, stage III mean, 0.11 years). However, after adjusting for quality-of-life, No CPM was favored in all cohorts. Univariate sensitivity analysis demonstrated that the most influential model parameter was the post-CPM health state utility. The preferred strategy shifted from No CPM to CPM when the post-CPM utility exceeded 0.83 (base case value 0.81). PSA indicated that LE gains and QALE decreases were stable in all cohorts. The primary determinant of survival after unilateral breast cancer is stage at diagnosis. Our results suggest that routine CPM would not improve quality-adjusted survival for the majority of women with unilateral sporadic breast cancer.