Prognostic Value of Tumor Deposits in Patients with Colorectal Cancer

Tumor nodules or tumor deposits (TDs) are a histopathological prognostic factor that are associated with a negative evolutionary course in patients with colorectal cancer (CRC). There are still controversial aspects of TDs, including how they should be integrated into the TNM classification system. The objective of this study was to analyze the predictive value of TDs for cancer-related survival (CRS) and time-to-recurrence survival (TTR) and to evaluate the prognostic value of TDs in patients whose tumors also presented lymph node metastasis (LNM). In this retrospective observational study, all patients treated for CRC between January 2010 and December 2020 at the same hospital were included. CRS and TTR were classified by tumor stage. The results were compared between patients whose tumors had TDs and patients whose tumors did not. A total of 1426 patients met the criteria for inclusion in the analysis. TDs were detected in 178 patients (12.5%): 60 had tumors without LNM, and 118 had LNM. Patients with TD tumors had a lower CRS at 60 months after diagnosis (42% vs. 82%; p < 0.001) and a shorter TTR (34% vs. 79%; p < 0.001). Cox multiple regression analysis revealed that the presence of TD was associated with an increased risk of death from CRC (HR: 1.820; 95% CI: 1.327-2.496) and an increased risk of recurrence (HR: 2.315; 95% CI: 1.743-3.073). In each N stage category, the CRS was significantly lower in the subgroup with TD⁺: in patients with N1a tumors, the CRS was 44% when TD⁺ vs. 70% when TD^- (p = 0.019); in the N1b group it was 36% vs. 66% (p < 0.001); in the N2a group it was 34% vs. 58% (p = 0.012); and in N2b tumors it was 23% vs. 53% (p = 0.031). The present study shows that the information on the presence of TDs is complementary to that provided by LNM and allows the identification of subgroups of patients in each N stage determined by two metrics, CRS and TTR. TDs should be included in the definition of TNM system categories in patients who simultaneously present with LNM.