Long-term survival comparison of repeated breast conserving surgery vs. mastectomy for DCIS patients with ipsilateral breast tumor recurrence: A real-world longitudinal study

Abstract Purpose: Although patients diagnosed with ductal carcinoma in situ (DCIS) harbor excellent overall survival after breast conserving therapy, the evidence regarding to surgical management for ipsilateral breast tumor recurrence (IBTR) is scarce. This study aimed to assess the prognosis of repeated breast conserving surgery (BCS) vs. mastectomy for IBTR in DCIS survivors. Materials and Methods: Herein, 5,344 DCIS cases with IBTR were identified during 702,748 person-years of follow-up, 3532 (66.09%) received mastectomy, and 1812 (33.91%) received repeated BCS. Cox regression and competing risk regression were employed to estimate multivariable-adjusted hazards ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival (OS) and breast cancer-specific survival (BCSS), which was respectively calculated within spontaneous and matched cohort. Results: After adjustment for confounders, no statistically significant survival difference was observed between the repeated BCS and mastectomy for DCIS patients with IBTR. The stratified analyses further revealed that DCIS patients with IBTR receiving repeated BCS combined with radiation therapy, were associated with both superior OS (HR, 0.79, CI, 0.64 to 0.98; P, 0.04) and BCSS (HR, 0.54, CI, 0.33 to 0.90; P, 0.02) compared with counterpart undergoing mastectomy. Furthermore, DCIS patients who aged more than 60 years old at IBTR diagnosis benefit from repeated BCS with radiotherapy (HR, 0.44, CI, 0.24 to 0.84, P,0.01) than mastectomy. Conclusion: We suggest that repeated BCS with radiation therapy deserves taking into consideration when DCIS survivors suffered IBTR. The choice of surgical management should be tailored based on patients’ age at IBTR diagnosis and size of recurrent disease.