Time Interval Between Neoadjuvant Chemotherapy Completion and Mastectomy is Not Associated with 30-Day Complication Rate.

Abstract

The optimal interval between neoadjuvant chemotherapy (NAC) and breast surgery remains unclear. We evaluated whether time to surgery (TTS) affects 30-day postoperative complications. Review was performed of all women undergoing mastectomy with or without reconstruction following NAC at a single institution between 2014-2024. The 30-day postoperative complications were analyzed by TTS using chi-squared tests for univariate analysis and logistic regression for multivariable analysis. A total of 862 patients were identified with mastectomy following NAC with a median age of 49 (range 22-86) years, and 30-day complications occurred in 54 patients (6.3%, 95% CI 4.8-8.1%), including hematoma (n = 11), surgical site infection (n = 19), necrosis (n = 19), thromboembolism (n = 3), and C. difficile infection (n = 2). 30-day surgical complications were not different between those treated with immunotherapy (4.3%) versus without (6.4%, p = 0.79). TTS was 20-62 days in 90% of patients. Median TTS was 32 (IQR 27-40) days, which did not differ between patients with and without a complication (p = 0.85). Adjusting for age, smoking, type of mastectomy, and surgery year on multivariable analysis, there was no significant association between TTS and 30-day surgical complications (adjusted OR for TTS ≤ 32 days versus > 32 days 1.30, 95% CI 0.75-2.29, p = 0.35). Recurrence-free survival was similar between patients with TTS ≤ 32 days versus > 32 days, both overall (78.9% versus 80.7% at 5 years, p = 0.29) and when stratified by residual cancer burden and tumor biology. TTS between 3 and 9 weeks after NAC was not associated with higher 30-day clinically significant complications. These findings support reasonable scheduling flexibility, but they do not establish safety of very early or delayed surgery outside this window.