Use of tumor size to predict long-term survival in colon cancer patients: Analysis of National Cancer Data Base (NCDB).

Abstract

3583 Background: Tumor size (TS) is a known prognostic factor in breast, renal, and lung cancers, however, not in colon cancer (CCa). Tumor (T) depth, nodal status (N), and metastasis (M) are used in the TNM staging. Hence, we studied if TS is an independent risk factor for death in CCa. Methods: Data included TS, grade, T-stage, N, and M-status from the NCDB for 298,021 CCa pts (1998-2010). We divided pts into 4 groups by TS (<2cm;2-4cm;4-6cm;>6cm). Data was analyzed using Spearman’s rho correlation (r) and Kaplan-Meier for overall 5-yr survival (5yrOS). Hazard ratios (HR) were calculated using a Cox model adjusting for age, sex, grade, T, N-status and TNM stage. Results: Proportion of pts with TS 0-2, 2-4, 4-6 and >6cm were 13.25%, 38.95%, 29.54%, and 18.26% respectively. Median TS was 4cm. TS was positively correlated with grade, T, N-status and TNM stage (p=0.0001) and negatively correlated with 5yrOS (65.5%, 52.4%, 45.5%, and 41.2% for four sizes respectively) (Table). Cox modeling demonstrated TS of 4-6cm and >6cm had HRs of 1.23 (95%CI 1.14-1.34) and 1.7 (95%CI 1.5-1.8) respectively. Conclusions: A primary TS of 4-6cm and >6cm is associated with a 23% and 70% increased risk of death, respectively, over 5-yrs in CCa. Prospective studies are needed to evaluate the role of primary TS in CCa prognosis. [Table: see text]