TIME DEPENDENCY OF THE INFLUENCE OF PROGNOSTIC FACTORS ON RELAPSE IN BREAST-CANCER

Background. A number of factors concerning the prognosis of cancer pat ients have been reported, but the evaluation of individual factors is not always consistent. The author considered that the discrepancies ma y lie in part in that factors may have a changing influence on relapse with time. The present study was intended to reveal the phenomenon an d its clinical significance in patients with breast cancer. Methods. E leven pathological prognostic factors in 462 patients with primary bre ast cancer were analysed with special reference to the influence on re lapse and its changes with time. The Cox regression analysis was perfo rmed for whole and three stratified non-overlapping observation period (within 2, 2-5 and 5 years more), using factors including extent of n odal involvement (N), nuclear grade (NG), tumor infiltrating lymphocyt es (TIL), tumor size, fat infiltration (F) and others. Results. Cox re gression analysis for whole observation period showed N followed by NG , TIL, F and others as the most important factors on relapse. But the analysis performed for 3 stratified intervals revealed that the influe nce on relapse decreased with time for N and NG, but tended to increas e with time for F. The suppressive effect of TIL on relapse was not ev ident up to 2 years but was significantly emphasized after 2 years pos toperatively. Conclusions. In conclusion, a distinct time-dependency w ith varied patterns was found in the influence of some prognostic fact ors on relapse, which implies the assessment of prognostic factors may vary according to the length of the observation period.