Histopathological grade, mucinous differentiation and DNA ploidy in relation to prognosis in colorectal carcinoma

Aims: We investigated parameters which might help identify poor prognosis c olorectal cancers and, in particular, we stratified Dukes' stage B carcinom as in order to identify those patients who would benefit from adjuvant ther apy. Methods and results: Histopathological parameters and DNA ploidy were analy sed in a consecutive series of 256 resected colorectal cancers and their re lationship with patient survival were investigated. By univariate analysis, Dukes' stage, degree of differentiation, nature of the invasive margin and DNA ploidy all correlated with prognosis, However, degree of differentiati on assessed by the worst pattern seen anywhere in the tumour correlated mor e significantly with clinical outcome than did the predominant pattern, Thi s was confirmed by multivariate analysis which showed only Dukes' stage and worst pattern differentiation as independent prognostic variables. Mucinou s carcinomas showed no significant difference in outcome when compared to a denocarcinomas, DNA ploidy correlated with prognosis but only at a low leve l (P = 0.035) but this was maintained for Dukes' B carcinomas, Conclusions: Dukes' stage and degree of differentiation provide independent prognostic information in colorectal cancer. However, differentiation shou ld be assessed by the worst pattern and not by the predominant pattern as i s currently recommended by the UKCCCR. DNA ploidy provides some prognostic information and does stratify Dukes' B cancers and thus might provide usefu l information on which to base decisions concerning adjuvant therapies in t his difficult group, Mucinous differentiation has no prognostic significanc e.