Objective: To investigate the prognostic value of tumor deposits (TDs) counts in stage III colorectal cancer (CRC) patients and develop a prognostic nomogram.
Methods: Data on stage III CRC patients from 2010 to 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier analysis was used to assess differences in survival outcomes among patients. The Cox regression analysis was performed to establish the independent prognostic factors for cancer-specific survival and to establish a nomogram. The nomograms' performance was evaluated by calibration plots and concordance index (C-index). Decision curve analysis (DCA) was used to assess the clinical utility of the prediction model.
Results: A total of 23,345 CRC patients were included in this study, and 3,578 (15.3%) had TDs. Cox multivariate regression analyses revealed that age, race, histological tumor grade, the administered chemotherapy, pathological type, T-stage, CEA, N-stage, peripheral nerve invasion, and TDs were independent prognostic factors. Patients with many TDs (=0/1-4, HR: 1.325,/≥5 HR: 2.223) had poorer cancer-specific survival. The prognostic value of the number of TDs was comparable to that of lymph node metastasis. The C-indices of the nomogram were superior to TNM staging in training (0.730 vs 0.646) and validation (0.714 vs 0.636) groups. DCA revealed that the nomogram had a higher clinical net benefit compared to TNM staging.
Conclusions: TDs count is an adverse prognostic factor for stage III CRC patients. Furthermore, the TDs-based nomogram can accurately predict the prognostic outcomes for stage III CRC.
Keywords: Tumor deposits counts; colorectal cancer; nomogram; prognosis.