Abstract 3394: Impact of gBRCAs mutation on the surgery decisions of Chinese breast cancer (BC) patients: a single-center real world study in Xijing Hospital, Northwest China

Abstract Background and Objective: Germline BRCA (gBRCA) mutations complicate clinical surgery management due to a higher risk of initial breast cancer, as well as increased chances of new primary cancers or local recurrence. In this study, we examined the surgical decisions for individuals carrying gBRCA mutations. Methods: In this real world study, 1050 female patients with unilateral operable invasive breast cancer getting gBRCA mutation test were enrolled. Pearson chi-square test, continuous correction chi-square test and Fisher's exact test were used to explored the association between gBRCA mutation and surgery choice appropriately. Results: Germline BRCA1 mutations (gBRCA1mut), Germline BRCA2 mutations (gBRCA2mut) and gBRCA1/2mut were found in 5.1% (54/1050), 4.9% (51/1050), 10.0% (105/1050) BC patients separately. Among all patients, those with gBRCAsmut preferred contralateral prophylactic mastectomy than those without mutation (9.3% gBRCA1mut patients compared with 2.0% gBRCA1wt patients, 7.8% gBRCA2mut patients compared with 2.1% gBRCA2wt patients, 8.6% gBRCA1/2mut patients compared with 1.7% gBRCA1/2wt patients, all p<0.05). This tendency could also be found in early-stage BC patients (n=699). While in young (≤40) BC patients (n=346), there were no significant differences in choice between gBRCAsmut cohort and gBRCAswt cohort. Though in all patients, the selection of specific surgery [breast-conserving surgery (BCS), mastectomy or reconstruction surgery] was not affected by gBRCAs mutations. In young BC patients, patients with gBRCA2mut were more likely to choose mastectomy or reconstruction surgery rather than BCS (10.3% gBRCA2mut patients selected BCS compared with 34.4% gBRCA2wt patients, p=0.011). The same tendency could also be found in early-stage BC patients though the difference was not statistically significant (p=0.074). The gBRCA1 mutation had no influence on the specific option. Conclusion: Northwest Chinese BC patients made their surgery choice under the influence of gBRCA1/2 mutation. gBRCA2mut played an more crucial role on it. Citation Format: Ting Wang, Jing Fan, Jiajun Ding, Jing Kong, Mengxuan Li, Yidi Wang, Huimin Meng, Haoyi Zi, Qingxia Li, Shuai Wang, Fei Yao, Changbing Zhu. Impact of gBRCAs mutation on the surgery decisions of Chinese breast cancer (BC) patients: a single-center real world study in Xijing Hospital, Northwest China [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3394.