Development and validation of a novel prognostic nomogram including tumor deposits could better predict survival for colorectal cancer: a population-based study

BACKGROUND: The number of tumor deposits (TDs) in colorectal cancer (CRC) prognosis remains debated. We evaluated whether the number of TDs affects prognosis in stage III CRC patients. METHODS: Univariate and multivariate analyses were performed with Cox proportional hazards models. The Kaplan-Meier method was used to estimate survival curves. The best cutoff was determined using X-Tile. Patients were 1:1 randomly divided into the training set or the testing set. Prognostic nomogram was established for stage III CRC patients. Concordance index (C-index) and calibration plot were used to assess Nomogram models. RESULTS: In total, 18,043 (84.69%) CRC patients without TDs and 3,263 (15.31%) patients with TDs were analyzed. Patients with TDs had significantly worse cancer-specific survival (CSS) rates (P<0.001). The number of TDs is an independent factor for the CSS of stage III CRC patients. CSS nomogram of stage III CRC patients was constructed based on race, age at diagnosis, tumor location, histological grade, pathological type, T, N, TDs, chemotherapy. In training set, C-index for CSS nomogram 0.762 (95% CI: 0.752–0.772). In testing set, the C-index for CSS nomogram 0.759 (95% CI: 0.749–0.768). The quality of calibration plots of nomogram models was high. CONCLUSIONS: The presence of TDs is an independent risk prognostic factor for stage III CRC. The number of TDs had a high proportion of prognostic impact.