Chemotherapy for ipsilateral breast tumor recurrence: a propensity score-matching study

Purpose We evaluated the benefit of chemotherapy in patients with ipsilateral breast tumor recurrence (IBTR) by comparing the survival outcomes between the chemotherapy and no chemotherapy groups, using propensity score matching (PSM), and analyze the survival outcomes stratified by hormone receptor status of IBTR. Methods We retrospectively analyzed patients who developed invasive IBTR after undergoing breast-conserving surgery at our institution between 1990 and 2013. A 1:1 PSM analysis was performed to compare the survival rates between the two study groups; additional analysis stratified by hormone receptor status was performed. The Kaplan–Meier method and Cox proportional hazards model were used to compare the second recurrence-free survival (RFS), distant metastasis-free survival (DMFS), and overall survival (OS) rates between the two groups. Results The 217 IBTR patients had a median follow-up of 125.3 months. After PSM, patients without chemotherapy and with chemotherapy ( n = 35 in both groups) were included. No significant differences were observed in the 10-year second RFS [50.2% without chemotherapy vs. 39.8% with chemotherapy, hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.50–1.80], DMFS (85.4% vs. 70.3%, HR 1.51, 95% CI 0.66–3.44), and OS (81.6% vs. 68.6%, HR 1.73, 95% CI 0.76–3.90) rates between the two groups. Analyses stratified by hormone receptor status showed similar findings: no significant differences were observed in the second RFS, DMFS, and OS rates between the two groups in both hormone receptor-positive and -negative groups. Conclusion Chemotherapy had no impact in the long-term survival outcomes of IBTR patients regardless of the hormone receptor status.