[Prognostic factors in colorectal adenocarcinoma of Dukes stage B. Study of a series of population].

A study of prognostic factors in Dukes B colorectal adenocarcinoma was performed on a population basis in order to determine subgroups with poor prognosis which could benefit from adjuvant therapy after surgery. The study considered the 746 cases of Dukes B colorectal carcinoma diagnosed during the 1976-1988 period among Côte-d'Or residents (Burgundy, France). The overall 5-year crude survival rate was 55.7%, the corresponding relative survival rate being 73%. In the final Cox model, age, tumour extension to adjacent organs, number of examined lymph nodes and tumour size were significant prognostic factors. The corresponding multivariate relative survival model considered only tumour extension and number of examined lymph nodes as having a prognostic value. The relative risk of death was 2.3 (range: 1.5-3.3) in case of a tumor extension and 2.5 (range: 1.5-4.4) when no lymph node was found compared to surgical samples with at least 6 lymph nodes. These data should be taken into account when conceiving or analyzing future therapeutic trials.