Factors influencing the decision for contralateral risk-reducing mastectomy in Japanese patients with breast cancer harboring <i>BRCA1/2</i> pathogenic variants: The BRCA-Decision study.

Abstract

e22661 Background: Contralateral risk-reducing mastectomy (CRRM) is an option for reducing contralateral breast cancer risk in patients with BRCA1/2 pathogenic variants (BRCA1/2 PV). However, decision-making involves complex interactions of patient values, life circumstances, and psychological factors. The specific factors influencing CRRM selection among Japanese patients remain inadequately characterized. This study aimed to elucidate differences in patient characteristics and decision-making factors between those who underwent CRRM and those who did not. Methods: A multicenter cross-sectional survey was conducted among primary breast cancer patients diagnosed with BRCA1/2 PV after April 2020 who were at least 3 months post-surgery. Factors influencing CRRM decision-making were evaluated in 160 patients who completed the web-based questionnaire. Results: Compared with the non-CRRM group, the CRRM group had significantly higher proportions of patients aged ≤50 years (60.0% vs 42.9%, P = 0.038) and full-time workers (54.4% vs 32.9%, P = 0.021), and a lower proportion of smokers (1.1% vs 8.6%, P = 0.009). In decision-making, the CRRM group demonstrated greater influence from physician opinions (84.3% vs 68.3%, P = 0.020), higher anxiety regarding new breast cancer development (88.8% vs 70.3%, P = 0.004), and greater expectations for survival improvement (88.6% vs 61.9%, P &lt; 0.001). Conversely, the CRRM group showed lower concerns about surgical complications (38.9% vs 61.9%, P = 0.005), resistance to removing healthy breasts (47.8% vs 74.6%, P = 0.001), anxiety about physical function limitations (32.2% vs 56.2%, P = 0.003), and perceived time burden of postoperative recovery (54.4% vs 70.8%, P = 0.039). Conclusions: This represents the first large-scale study examining factors influencing CRRM decision-making in Japanese patients with breast cancer harboring BRCA1/2 PV. CRRM uptake was strongly influenced by younger age, employment status, physician opinions, and psychological factors, providing important implications for individualized decision-making support. Factors influencing the decision for contralateral risk-reducing mastectomy in japanese patients with breast cancer harboring brca1/2 pathogenic variants. Characteristic CRRM Group Non-CRRM Group P-value Age ≤50 years 60.0% 42.9% 0.038 Full-time workers 54.4% 32.9% 0.021 Current smokers 1.1% 8.6% 0.009 Influenced by physician opinion 84.3% 68.3% 0.020 Anxiety regarding new breast cancer 88.8% 70.3% 0.004 Expectation for survival improvement 88.6% 61.9% &lt;0.001 Concerns about surgical complications 38.9% 61.9% 0.005 Resistance to removing healthy breasts 47.8% 74.6% 0.001 Anxiety about physical function limitations 32.2% 56.2% 0.003 Perceived time burden of recovery 54.4% 70.8% 0.039