Colorectal carcinoma: importance of clinical and pathological factors in survival.

A series of clinicopathological variables was assessed on 312 patients undergoing surgical resection for primary colorectal cancer. Although the presence of venous invasion was related to mortality (P = 0.02), classifying invasion into involvement of thick-walled or thin-walled veins did not produce a variable of prognostic value. Intestinal obstruction (P = 0.04) and the macroscopic appearance of the tumour (P = 0.04) were related to mortality from colorectal cancer, but not from all causes of death. Duke's stage, increasing patient age and poorly differentiated tumours were the variables which were individually most significantly related to poor prognosis (P < 0.001 for each analysis). Cox's regression analysis identified these three variables as independent predictors of outcome in colorectal cancer. This study confirms that Duke's stage, patient age and tumour differentiation are still the most important clinicopathological variables in colorectal cancer.