Management of ipsilateral breast tumor recurrence after prior breast conservation therapy.

Objective: Mastectomy is traditionally recommended for local recurrence after breast conservation therapy (BCT), the combination of lumpectomy followed by whole-breast radiotherapy. Recent studies suggest that repeat BCT (lumpectomy and re-irradiation) may be feasible for select patients. We sought to evaluate the clinical characteristics, management strategies, and outcomes of patients treated for ipsilateral breast tumor recurrence (IBTR) after initial BCT and assess the impact of a newly adopted multidisciplinary algorithm for repeat BCT (lumpectomy and re-irradiation).

Methods: We identified patients with stage 0-III breast cancer treated with initial BCT who underwent surgery for IBTR between January 2016 and May 2023. Patient, tumor, and treatment characteristics were analyzed, and outcomes were compared before and after the adoption of the repeat BCT algorithm.

Results: Among 546 patients treated for IBTR, 48% were eligible for repeat BCT. After criteria adoption, mastectomy rates decreased by 16%. The proportion of eligible patients undergoing lumpectomy alone (BCS) for IBTR increased by 9% while only a modest increase in lumpectomy and re-irradiation (repeat BCT) was observed (7%). Rates of BCS for IBTR were higher than repeat BCT among older patients. Clinical outcomes were comparable between patients treated with BCS, BCT, or mastectomy.

Conclusions: Repeat BCT (lumpectomy and re-irradiation) is a viable option for select patients with IBTR, offering comparable outcomes to mastectomy. The adoption of standardized criteria for repeat BCT has increased its use, highlighting the importance of multidisciplinary approaches in treatment planning.