A SURVIVAL REGRESSION-ANALYSIS OF PROGNOSTIC FACTORS IN COLORECTAL-CANCER

Background: Many prognostic factors of colorectal cancer are known but their actual clinical validity is still uncertain. The aim of the pre sent study was to verify, on the basis of our experience, the prognost ic validy of variables for survival by using survival regression analy sis. Methods: From January 1978 to December 1986 the prognostic factor s for 192 patients were analysed. These patients had undergone surgica l resection for colorectal cancer. The follow up was completed in ever y patient by the end of December 1992, with a median follow up of 10 y ears (range 6-14 years). The prognostic factors considered in the stat istical analysis were age, sex, size of tumour, site, grade, direct sp read, node involvement and stage (according to Astler-Coller and pTNM) . Results: Of the prognostic factors, sex was the only one not to show any prognostic significance. In the survival regression analysis we h ave used an accelerated failure time model (equivalent to the Cox prop ortional hazard model); age, grade and stage were significant covariab les. Conclusions: Although clinical pathological staging (pTNM) appear s as a pre-eminent prognostic factor, and as our analysis shows, it ne eds a further variable (grading), which has been shown to affect the p rognosis in a significant way.