PATHOLOGICAL DETERMINANTS OF SURVIVAL ASSOCIATED WITH COLORECTAL-CANCER WITH LYMPH-NODE METASTASES - A MULTIVARIATE-ANALYSIS OF 579 PATIENTS

Background. Patients with colorectal carcinoma found to have regional lymph node metastases after curative resection form a large and progno stically diverse group. This study aims to determine which pathology v ariables have independent prognostic effects. Methods. The data from t he 579 patients used in this analysis were collected prospectively dur ing a period of 21.5 years. The patients were from one institution, an d the pathologic documentation was standardized. Patient follow-up ran ged between 6 months and 21.5 years. Survival analysis was by the Kapl an-Meier method. Multivariate models were examined using Cox proportio nal hazards regression. Results. On univariate analysis, eight patholo gy variables had a significant association with survival. Six of these variables showed significant independent effects on survival on multi variate analysis. In diminishing potency, these variables were: apical lymph node involvement; spread involving a free serosal surface; inva sion beyond the muscularis propria; location in the rectum; venous inv asion; high tumor grade. Significant independent effects also were sho wn for patient age and gender. The number of involved lymph nodes adde d no significant independent prognostic information. Conclusion. Six p athology variables have been identified that act independently in dete rmining the survival of patients with colorectal carcinoma and lymph n ode metastases. The most potent of these variables, apical lymph node involvement, was used by Dukes to subclassify Stage C tumors. Another variable, direct spread beyond the muscularis propria, defines the Ast ler-Coller subclassification. It is recommended that all six independe nt variables be included in any future protocol for stratifying this p rognostically diverse group of patients.