Risk of ipsilateral breast tumor recurrence in primary invasive breast cancer following breast-conserving surgery with BRCA1 and BRCA2 mutation in China Abstract Purpose BRCA1/2 germline mutations are associated with a high risk of breast cancer, which may preclude mutation carriers from breast-conserving surgery (BCS). This study retrospectively examined whether mutation status influenced the rate of ipsilateral breast tumor recurrence (IBTR) after BCS  in Chinese women. Methods Patients who underwent BCS were enrolled in carriers group and non-carriers group according to their BRCA1/2 mutation status in the study. The correlations were analyzed between IBTR incidence and BRCA1/2mutation. The IBTR cases were further separated into new primary tumor (NP) and true local recurrences (TR). The risk factors of NP were studied in multivariate analysis. Results 1947 consecutive Chinese women with primary invasive breast cancer were selected. 103 patients were identified as BRCA1/2 mutation carriers and 1844 were non-carriers. BRCA1/2 mutation carriers were younger (P < 0.001) with more often negative HER-2 expression (P = 0.01) and tumor size over 2 cm (P = 0.04) than non-carriers. The median follow-up for all patients was 80 months. The rate of IBTR was 3.9% in mutated carriers and 2.0% in non-carriers, respectively (P = 0.16). In IBTR cases, NP incidence was 3.9% in carrier group and 0.6% in non-carrier group, respectively (P < 0.01). After adjustment of all clinical-pathological factors, BRCA1/2mutation was the only statistical risk factor of NP incidence (HR = 6.29, P = 0.002), while positive lymph node was nearly statistically significant (HR = 2.70, P = 0.06). Conclusions BCS may be a rational option for Chinese BRCA1/2 mutation carriers. High NP incidence in mutation carriers should be paid close attention in the future.