The prognostic impact from the difference of surgical procedure after ipsilateral breast cancer recurrence.

1106 Background: Mastectomy is the current standard of surgical procedure for ipsilateral breast cancer recurrence (IBTR). However, there is little evidence about a prognostic impact of surgical procedure after IBTR, due to small number of incidence of IBTR. Methods: A total of 271 consecutive patients who had histologically confirmed IBTR without distant metastases and underwent definitive surgery for the IBTR between 1989 and 2008 were included from eight institutions as a scientific research from the Japanese Breast Cancer Society. Distant Disease free survival (DDFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed using the log rank test and multivariate analysis by Cox's proportional hazard model. Results: Of the 271 patients, 149 patients (55%) underwent lumpectomy and 122 patients (45%) underwent mastectomy after IBTR. One hundred thirty four patients (49%) did not receive radiation therapy after initial lumpectomy (52% in lumpectomy patients and 47% in mastectomy patients). The median follow-up period from definitive surgery for IBTR was 55 months. Seventy-six patients (28.2%) relapsed after IBTR (23.7% of lumpectomy patients, 33.6% of mastectomy patients). In comparing groups by type of surgery, patient and tumor demographics in each group were significantly less positive HER2 status and smaller tumor size of IBTR, and more receiving adjuvant endocrine therapy and less adjuvant chemotherapy for IBTR in lumpectomy patients compared with mastectomy patients. On univariate analysis, lumpectomy group was significantly longer DDFS than mastectomy group (p=0.012), but this difference was not appeared on multivariate analysis (p=0.35). Furthermore, only using small IBTR (<2cm) population, this difference was not appeared (p=0.71). On multivariate analysis, the time intervals from initial surgery to IBTR (<5years) (HR, 1.93; 95%CI, 1.01-3.67; p=0.047) and lymphovascular invasion of the IBTR (HR, 2.31; 95%CI, 1.18-4.52; p=0.015) were independent predictive factor for poor DDFS. Conclusions: Our study suggests that the type of surgical procedure after IBTR does not affect DDFS. Further analyses are needed. (UMIN-CTR number UMIN000008136).