Factors associated with locoregional recurrence after neoadjuvant chemotherapy for breast cancer in a safety-net medical center.

Background: The management of locally advanced breast cancer poses significant challenges, with contemporary strategies involving an approach that combines systemic and local treatment. The current study was performed to validate the clinical impression that locoregional recurrences have become increasingly uncommon after standardized multimodal treatment protocol.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.All authors and affiliations are correct.

Methods: A retrospective analysis was performed using a single-institution database that included clinical, radiographic, and pathologic parameters for all non-metastatic and non-inflammatory breast cancer patients treated with neoadjuvant chemotherapy (NAC) from 2015 to 2023. Uni- and multivariable analyses were performed to define associations between clinical factors, recurrence, and RFS.

Results: The median age was 51 years for 274 predominantly Hispanic (78%) patients, with a median follow-up of 38.1 months. The recurrence rates were 4% local, 2% regional, and 18% distant. Median time from surgery to local recurrence was 8.2 months and to regional recurrence was 9.7 months. There were no locoregional clinical recurrences in 92 (34%) patients who had pCR or in 85 (31%) patients who had radiological complete response after NAC. Locoregional recurrences were uncommon > 12 months after surgery. Five of 11 local recurrences occurred in patients who had a poor response to NAC (ypT4b). All 6 patients having regional recurrences had adjuvant radiation therapy, and only 2 occurred in patients who were pathologically node-negative (ypN0) post-NAC.

Conclusions: Favorable responses to NAC were associated with excellent locoregional control rates. Results achieved for predominantly Hispanic patients at a safety net medical center were similar to those reported in prospective, randomized clinical trials.