Prognosis factor of patients with colorectal cancer: a retrospective study of surveillance, epidemiology, and end results population-based data

Abstract

Objective To explore the survival of different stage of patients with colorectal cancer, and evaluate the clinicopathologic factors associated with prognosis. Methods The SEER*Stat software was used to identify patients whose pathological diagnosis as colorectal malignancy from 2004 to 2009, and underwent surgical treatment. Univariate and Cox multivariate regression analysis were applied to evaluate the prognostic factors. The Kaplan-Meier method was used to calculate the cumulative survival rate, and the significant difference was evaluated by the log-rank test. Results The mean survival time of 1 829 colorectal cancer patients was (76.71±0.16) months, the median survival time was 98 months and the overall 5-year survival was 60.4%. The 5-year survival rates of the stage Ⅰ, Ⅱ, Ⅲ, Ⅳ patients were 81.2%, 71.7%, 58.4%, 14.4%, and the relationship between the overall survival was stage Ⅰ> stage Ⅱ> stage Ⅲ> stage Ⅳ (χ2=26 063.383; P<0.001). But, the overall survival of stage Ⅱwas located between stage ⅢA and ⅢB. The overall 5-year survival of stage ⅢA (78.7%) and ⅠB (79%) was almost (χ2=0.040; P=0.841), and better than ⅡA (χ2=39.409; P<0.001), ⅡB (χ2=212.271; P<0.001), ⅡC (χ2=307.720; P<0.001). The overall 5-year survival of stage ⅢB (61.5%) was better than stage ⅡB (60.1%) (χ2=4.366; P=0.037) and ⅡC (54.6%) (χ2=33.047; P<0.001), but worse than stage ⅡA (73.6%) (χ2=692.563; P<0.001). The factors of sex (χ2=5.662; P=0.017), years of diagnosis (χ2=100.476; P<0.001), race (χ2=227.960; P<0.001), primary site (χ2=457.809; P<0.001), pathological grading (χ2=2 364.001; P<0.001), adjacent organ involvement (χ2=3 475.630; P<0.001), depth of invasion (χ2=8 281.813; P<0.001), lymph node metastasis (χ2=12 034.484; P<0.001), total number of lymph nodes (χ2=362.497; P<0.001) and metastasis (χ2=23 960.974; P<0.001) influenced the survival rate by univariate analysis. The factors of sex (95%CI: 0.958~0.997; P=0.025), years of diagnosis (95%CI: 0.967~0.992; P=0.001), race (95%CI: 0.912~0.942; P<0.001), Primary site (95%CI: 0.896~0.912; P<0.001), Pathological grading (95%CI: 1.162~1.204; P<0.001), adjacent organ involvement (95%CI: 0.758~0.832; P<0.001), depth of invasion (95%CI: 1.360~1.407; P<0.001), lymph node metastasis (95%CI:1.302~1.329; P<0.001), total number of lymph nodes (95%CI: 0.667~0.696; P<0.001) and metastasis (95%CI: 3.055~3.211; P<0.001) were available independent prognostic factors through multivariate analysis. Conclusions With the increase of TNM stage, the overall survival rate of patients with colorectal cancer undergoing radical surgery was gradually reduced. However, compared the prognosis of ⅡA、ⅡB、ⅡC with that of ⅢA、ⅢB, primary tumor invasion depth (T grading) may be more important than the number of lymph node metastasis (N grading) in predicting the prognostic value. In addition, the factors of sex, years of diagnosis, race, primary site, pathological grading, adjacent organ involvement, depth of invasion, lymph node metastasis, total number of lymph nodes and metastasis were available independent prognostic factors. This provided reference for the analysis of the prognosis of patients with colorectal cancer. Key words: Colorectal neoplasms; Prognosis; TNM classification; Survival