Abstract: Neoadjuvant chemoradiotherapy (nCRT) is used to downstage locally advanced rectal cancer before surgery, in order to increase the chance of radical resection, reduce local recurrence, and improve overall survival. Accumulating data suggest that tumor response to nCRT is time dependent. A delay between nCRT and surgery may increase the proportion of patients that achieve a favorable response, and 4-6 weeks are considered to be a universal interval. However, delayed surgery beyond 6-8 weeks may increase the technical difficulty, and the risks of surgical complications and recurrence or metastasis. This article briefly reviews the relevant literature to evaluate the efficiency and safety of delayed surgery.

Key words: Neoadjuvant chemoradiotherapy, Operation time interval, Locally progressed rectal carcinoma