resection than in the general population, regular colonoscopic examination of the large bowel is recommended. 6 In our study, 22 patients (0.5%) developed metachronous CRC within 5 years after surgery, which was detected during routine surveillance in all but one patient. Fortunately, in all cases, curative resection could be performed. Thus, postoperative surveillance is also effective in detecting, treating, and curing metachronous CRC.In conclusion, our results regarding peak recurrence time and the transition of recurrence hazard over time in patients with stage I, II, and III CRC will help set the optimal surveillance intervals for CRC according to stage. We would like to thank again Dr Wang and colleagues for their stimulating questions.