Nomogram for predicting recurrence in stage II colorectal cancer

Background: There have been no established criteria to distinguish patients at high and low risk of recurrence in stage II colorectal cancer. Several risk factors have been identified but recurrence could not be fully predicted by each factor alone. This retrospective study sought to develop a nomogram for accurate prediction of recurrence in stage II colorectal cancer. Material and methods: We reviewed the data for 4167 patients with stage II colorectal cancer who underwent surgery between January 1997 and December 2006. The risk factors for recurrence were identified, and a nomogram for recurrence was created using the factors. The performance of the nomogram was assessed with a bootstrapped-concordance index and calibration plots. Results: Sex, carcinoembryonic antigen, tumor location, tumor depth, lymphatic invasion, venous invasion and number of lymph nodes studied were significantly associated with recurrence. A nomogram for five-year freedom from recurrence was created with these factors. The bootstrapped-concordance index of the nomogram was 0.64, and it was well calibrated. Conclusions: Our nomogram can be a useful tool for accurate prediction of recurrence in stage II colorectal cancer.