Neoadjuvant chemoradiotherapy(nCRT) combined with total mesorectal excision is a standard treatment for locally advanced rectal cancer (LARC) [1]. About 15–30 % of patients reach pathological complete response (pCR) after nCRT [2,3]. Patients with pCR suggests favorable prognostic biological tumor features and better survival [2]. These patients may benefit from organ preservation or watch-and-wait to avoid unnecessary surgery, especially those with lower rectal cancer and elder patients [4–6]. …