Staging of carcinoma of the colon and rectum

A retrospective study was carried out upon 393 patients diagnosed from the 1 January 1970 through 1 December 1978 for carcinoma of the colon and rectum, 90 per cent of whom had a complete follow-up study during a five year period or until death. A classification system by stage, which has given us good results since there are no crossovers in the survival evolution of the different subgroups, is described. The system shows great uniformity since a linear equation with a slope of 15.76 per cent and a linear correlation coefficient (r) = -0.999 relates almost perfectly the decrease in survival time as the stages advance.