JASS CLASSIFICATION REVISITED

BACKGROUND: In 1986, Jass and colleagues claimed to have improved on D ukes' classification of prognosis for carcinoma of the colon and rectu m. To have clinical relevance, such results should be reproducible and confirmed by other institutions. STUDY DESIGN: Retrospective clinicop athologic study of 312 carcinomas of the colon and rectum to determine whether or not Jass' classification is superior to that of Dukes' as assessed by their relative reproducibility and prognostic significance . RESULTS: Dukes' classification had excellent intraobserver and inter observer reproducibility (kappa values of 0.86 and 0.93, respectively) . In contrast, the reproducibility of variables assessed by Jass showe d only slight to fair agreement (lymphocytic infiltration: intraobserv er and interobserver kappa values of 0.08 and 0.05, respectively, grow th pattern: intraobserver and interobserver kappa values of 0.37 and 0 .41, respectively). Dukes' stage and patient age were the most importa nt prognostic variables on multivariate regression analysis. Tumor dif ferentiation, nuclear polarity, tubule configuration, and lymphocytic infiltration remained significantly related to survival in the presenc e of Dukes' stage and age. The model which best predicted prognosis wa s a combination of Dukes' stage, patient age and tumor differentiation . Further addition of the variables assessed by Jass to this model did not significantly improve the prediction of prognosis. CONCLUSIONS: D ukes' classification is of greater prognostic value and more reproduci ble than the components of Jass' classification. The continued use of Dukes' classification is, therefore, warranted for prognostic and ther apeutic decisions in patients with carcinoma of the colon and rectum.