MULTIVARIATE-ANALYSIS OF PROGNOSTIC FACTORS IN RESECTED COLORECTAL-CANCER - A NEW PROGNOSTIC INDEX

Objective We analysed different clinicopathological variables in color ectal cancer and their independent prognostic significance in order to elaborate a prognostic index, which may be used to categorize patient s into homogeneous groups and indicate adjuvant therapy. Design Retros pective study. Methods Patients (n = 108) undergoing surgery for color ectal cancer were studied (5-year-survival was controlled). Different clinicopathological variables and biological parameters (tumoural ploi dy, proliferating cell nuclear antigen PCNA and nucleolar organizing r egions NORs) were analysed. The Kaplan-Meier method and log-rank test were used for univariate analysis and the Cox regression method was us ed for multivariate analysis. Results Some variables with prognostic e ffect in univariate analysis (e.g. rectal bleeding, altered bowel habi t, intestinal obstruction, type of surgery, histological type, venous and neural invasion and invasive margin) did not have independent prog nostic significance after Cox analysis. Final multivariate analysis mo del was defined by five parameters: postoperative carcinoembryonic ant igen, Astler-Coller-Turnbull staging, histological grade, lymphatic in vasion and tumour ploidy. A new prognostic index was elaborated that p rovided information to group patients in three prognostic categories o f different risk: high, medium and low. Conclusion The prognostic inde x allowed categorization of patients into different risk groups with i dentical tumoural stage and histological grade. Therefore, this index provides better prognostic information that may be helpful when select ing patients for adjuvant therapy.