[Time-dependent interrelationships between pathological prognostic factors and relapse rate in breast cancer...

Eleven pathological factors among 462 patients with primary breast carcinoma (1960-1968) were analysed paying a special attention to changes of the influence on relapse. Factors were included; tumor size (T), extent of nodal involvement (N), nuclear grade (NG), fat infiltration (F), tumor infiltrating lymphocyte (TIL), tumor necrosis (NEC), lymphatic & vessel permeation (LY) and others. Cox regression analysis on 3 non-overlapping intervals (within 2 years, 2-5 years and after 5 years) using the seven factors selected by Cox analysis in the whole periods under the condition of p < 0.10 showed that significant factors were N, NG and T within 2 years, N, TIL, NG and NEC in 2-5 years, F, N, TIL and T after 5 years, respectively (p < 0.05), in the following order. TIL means the relapse suppressing factor and others mean relapse factors. As for the changes of beta value, it decreased with time for N and NG, but contrarily increased with time for F. This means that N and NG participate mainly in an early relapse and F mainly in a delayed relapse. TIL showed a significant relapse suppressing factor only after 2 years. These results revealed that prognostic factors have its altered influence on relapse with time, namely a distinct time-dependency.