Effect of time to breast cancer surgery after neoadjuvant chemotherapy on survival outcomes

Neoadjuvant chemotherapy (NACT) is a cornerstone in managing breast cancer. There is no defined consensus on the optimal time between NACT and surgery. We analyze the effect of time between the end of NACT and surgery on overall survival (OS) and disease-free survival (DFS) in breast cancer patients who received NACT followed by surgery.

This is a retrospective analysis of 468 patients with breast cancer (stage I-III) who received and completed the same regimen of NACT (Anthracyclines and Taxanes B27 protocol) at King Hussein Cancer Center (KHCC) (2006-2014). Patients have been divided into three groups according to the duration between the end of NACT and surgery, <4 weeks, 4-8 weeks and >8 weeks.

Most patients were stages II-III breast cancer with only four patients with stage I. Almost all patients (99%) had either invasive ductal or invasive lobular carcinomas. Adjuvant radiotherapy was given to 96% of patients. Most patients were alive at the time of analysis (84%). Complete pathological response was achieved in 20% of patients. Local recurrence rate was 6.6% with a median follow up of 3.8 years (interquartile range 0.6-10.9). Analysis showed that the groups had equivalent DFS. However, OS was adversely affected if patients had their surgery after 8 weeks of NACT compared to those who had their surgery between 4 and 8 weeks.

Breast cancer surgery post NACT within the first 8 weeks had no impact on survival. However, surgery after 8 weeks of NACT showed negative impact on OS. Therefore, delaying surgery after 8 weeks is not recommended.