Decisional Conflict About Contralateral Prophylactic Mastectomy in Patients with Breast Cancer with and Without Pathogenic Variants in BRCA Genes

<b>Background/Objectives</b>: Decision making for contralateral prophylactic mastectomy in patients with breast cancer involves complex risk-benefit trade-offs that may lead to decisional conflict. Understanding factors associated with decisional conflict, particularly for patients with pathogenic variants in <i>BRCA</i> genes, is critical for developing tailored decisional support. This study examined decisional conflict, shared decision making, and decisional role preferences in Korean patients with breast cancer considering contralateral prophylactic mastectomy, focusing on factors associated with clinically significant decisional conflict and differences by <i>BRCA</i> status. <b>Methods</b>: A cross-sectional, internet-based survey was conducted between August and October 2024. Independent <i>t</i>-tests, univariate, and multivariate logistic regression analyses identified factors associated with clinically significant decisional conflict. <b>Results</b>: The sample included 167 Korean patients with breast cancer (90 <i>BRCA</i> carriers and 77 non-carriers). Most patients (76%) experienced clinically significant decisional conflict. Non-carriers reported higher decisional conflict (44.2 vs. 29.3, <i>p</i> < 0.001) and lower shared decision making than <i>BRCA</i> carriers (44.6 vs. 61.9, <i>p</i> < 0.001). Role preferences were similarly distributed across groups (50.3% active, 24.0% collaborative, 25.7% passive). In multivariable analysis, clinically significant decisional conflict in the total sample was associated with non-carrier status (OR = 2.98) and lower shared decision-making scores (OR = 0.94) (<i>p</i> < 0.05), explaining 28% of the variance. Among <i>BRCA</i> carriers, clinically significant decisional conflict was associated with lower shared decision-making scores (OR = 0.92) and passive role preferences (vs. active) (OR = 4.88). No variables were significantly associated with decisional conflict among non-carriers. <b>Conclusions</b>: Findings suggest that decisional conflict is influenced by genetic risk and the quality of the decision-making process. Improving patient engagement by identifying preferred decisional roles, understanding the reasons behind these preferences, and encouraging shared decision making may help reduce decisional conflict, particularly among <i>BRCA</i> carriers. Further research is needed to better understand factors associated with decisional conflict among non-carriers.