Management of ipsilateral breast tumor recurrence following breast conservation surgery: a comparative study of re-conservation vs mastectomy

Background Breast conservation therapy (BCT) is well established for the management of primary operable breast cancer, with oncologic outcomes comparable to those of mastectomy. It remains unclear whether re-conservation therapy (RCT) is suitable for those patients who develop ipsilateral breast tumor recurrence (IBTR), for whom mastectomy is generally recommended. Methods We identified women who underwent BCT for invasive or ductal carcinoma in situ and developed IBTR as a first event, comparing the pattern of subsequent events and survival for those treated by RCT versus mastectomy. Results Of 16,968 patents who had BCT, 322 (1.9%) developed an isolated IBTR as a first event between 1999 and 2019. 130 (40%) had RCT and 192 (60%) mastectomy. Compared to mastectomy, the RCT patients were older (66 vs 53,