Purpose: The optimal time interval from neoadjuvant chemotherapy (NAC) to surgery in patients with breast cancer has not been established. We investigated whether different time intervals impact the rate of pathologic complete response (pCR), disease free survival (DFS), overall survival (OS), surgical complications, and rates of conversion from mastectomy to breast conserving surgery (BCS) in this population.
Methods: We identified patients who received NAC at the BC Cancer Agency followed by surgery from May 2012 to April 2018. Patients were grouped based on time interval between NAC and surgery: < 4 weeks, 4-8 weeks, and > 8 weeks. Kaplan Meier method was used to estimate DFS and OS. Rates of pCR between the time intervals were also compared.
Results: Of the 343 patients, 78 (22.8%) received surgery < 4 weeks, 233 (67.9%) received surgery between 4-8 weeks, and 32 (9.3%) received surgery > 8 weeks after NAC, with a median time to surgery (TTS) of 5.0 weeks. pCR was observed in 32.1%, 32.2%, and 28.1%, respectively (p = 0.90). Median follow-up time was 3.3 years. The 5-year DFS was 76%, 78%, and 70% (p = 0.89), respectively. The 5-year OS was 83%, 82%, and 78% (p = 0.33), respectively. No statistically significant differences were seen in surgical complications (p = 0.90), or rates of conversion from mastectomy to BCS (p = 0.19).
Conclusions: There were no statistically significant differences in pCR, DFS, OS, surgical complications, and rates of conversion from mastectomy to BCS, among breast cancer patients receiving surgery < 4 weeks, 4-8 weeks, or > 8 weeks after the last dose of NAC.
Keywords: Breast cancer; Neoadjuvant; Overall survival; Pathologic complete response; Wait times.