The association between small tumor size and poor survival in T4 mucinous adenocarcinoma of colon without distant metastasis.

PURPOSE: The purpose of this study was to analyze the impact of tumor size on cancer-specific survival (CSS) in patients with mucinous adenocarcinoma (MAC) of the colon, showing heavy intestinal wall invasion without distant metastasis (T4 N0-2 M0).

METHODS: Patients with T4N0-2M0 MAC of colon were analyzed based on data from the US Surveillance, Epidemiology, and End Results (SEER) database. Survival was analyzed using the Kaplan-Meier method, and the log-rank test was used to identify differences. Risk factors were analyzed using the Cox proportional hazard model. A preliminary analysis of T4N0-2M0 adenocarcinoma of colon patients from the SEER database is also presented.

RESULTS: A total of 585 patients from the SEER database were included in the analysis. The cutoff value (5.0 cm) was determined using the X-tile program. Kaplan-Meier analysis showed that tumors ≤5.0 cm had a poorer CSS compared to tumors >5.0 cm (p=0.034). Multivariate analysis indicated that tumor size is an independent prognostic factor for these patients, and compared to tumors ≤5.0 cm, tumors >5.0 cm were more likely to have better CSS (HR 0.658, 95% CI 0.506-0.854, p=0.002). Tumor size was also analyzed as a continuous variable in multivariate analysis, and CSS decreased with decreasing tumor size (HR 0.919, 95% CI 0.873-0.968, p<0.001). No significant association between tumor size and CSS was observed in patients with T4N0- 2M0 MAC of the colon.

CONCLUSION: Smaller tumor size is associated with poorer CSS in patients with T4N0-2M0 MAC of the colon.