Factors predictive of survival in patients with node-positive colorectal cancer in Taiwan

Background/Aims: Preoperative CEA levels, depth of tumor penetration, and t he number of positive lymph nodes were reported as independent factors prog nostic of survival in colorectal cancer patients. This study was carried ou t in an effort to evaluate the prognostic significance of these three facto rs in patients with Dukes' C colorectal cancer in Taiwan. Methodology: Between 1992 and 1994, a total of 112 patients with node-posit ive colorectal cancer were evaluated retrospectively at the Veteran General Hospital-Taipei. All patients underwent potentially curative surgery and r eceived 5-fluorouracil based adjuvant chemotherapy. Reference to the Dukes' classification was according to the classical criteria described in 1932 f or carcinoma of the rectum and adapted for use in colonic tumors. Data on t he location of the tumor, depth of penetration, number of positive lymph no des, degree of tumor differentiation, and preoperative CEA levels were anal yzed to understand their association with survival. Blood samples for CEA m easurement were taken a few days before operation. A multivariate analysis using the Cox's proportional hazards regression model was then performed to determine the most important independent predictors of survival among all the possible variables. Results: Using univariate analysis the number of positive lymph nodes (P<0. 001), penetration of the bowel wall (P<0.001), and preoperative CEA levels (P<0.001) were found as significant prognostic factors, while the degree of tumor differentiation, location of the tumor, age and sex were not signifi cant. Using multivariate Cox analysis the number of positive lymph nodes, p enetration of the bowel wall, and preoperative CEA levels were still found as independent prognostic factors in node-positive colorectal cancer patien ts. Conclusions: Data obtained from our study indicates that preoperative CEA l evels, depth of tumor penetration, and the number of positive lymph nodes w ere independent prognostic factors in Dukes' C colorectal cancer patients. They could serve as appropriate modifications of the initial Dukes scheme i n node-positive diseases.