Prognostic Value of Tumor Deposit Counts in Patients with Stage III Colorectal Cancer: A Population-Based Study

Abstract 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.