Omitting Axillary Surgery in Patients with Ipsilateral Breast Tumor Recurrence After Breast-Conserving Surgery.

[BACKGROUND] Axillary surgery for patients with ipsilateral breast tumor recurrence (IBTR) is feasible, but its necessity and impact on oncologic outcomes remain unclear. This study evaluated the role of axillary surgery for patients with clinically node-negative invasive IBTR.

[METHODS] The study identified breast cancer patients who had undergone breast-conserving surgery (BCS) at Asan Medical Center between 1990 and 2017 and later experienced invasive ipsilateral breast tumor recurrence (IBTR) as the first recurrence event. Cases with clinically node-positive disease or distant metastasis at recurrence were excluded from the analysis. Clinicopathologic features were compared using the chi-square test. Recurrence-free survival (RFS) after IBTR (second RFS) was analyzed using the Kaplan-Meier method and log-rank test in accordance with the axillary surgery status.

[RESULTS] Among the 200 enrolled IBTR patients in the study, 60 (30%) underwent axillary surgery. The median time from primary diagnosis to recurrence was 35.5 months (range, 2-278 months), and the follow-up period after IBTR was 56.5 months (range, 1-229 months). Axillary surgery at recurrence was more frequent for patients who had not undergone axillary surgery previously and for patients undergoing salvage mastectomy. No significant difference was observed in second RFS based on whether axillary surgery was performed (5 year second RFS 61.0% with axillary surgery vs 68.4% without axillary surgery; P = 0.308). Adjuvant treatments after recurrence were similar regardless of axillary surgery.

[CONCLUSION] Oncologic outcomes did not differ based on whether axillary surgery was performed for IBTR patients. The omission of axillary surgery could therefore be considered in cases with clinically node-negative IBTR.