THYMIDINE LABELING INDEX AND KI-67 GROWTH FRACTION IN BREAST-CANCER -COMPARISON AND CORRELATION WITH PROGNOSIS

In situ determination of proliferative activity was performed on 184 c onsecutive primary invasive breast cancers. Methods used were monoclon al antibody Ki-67 in immunohistochemistry and thymidine labeling index . Tumor proliferation correlated between both methods (p = 0.0001). Fo r thymidine labeling index and Ki-67, respectively, significant correl ations existed with histologic tumour grade and steroid hormone recept ors (Tumor grade: TLIp = 0.0001; Ki-67 p = 0.0001. ER-ICA: TLI = 0.000 1; Ki-67 p = 0.014. PgR-ICA: TLIp = 0.0001; Ki-67 p = 0.0008). For thy midine labeling index a significant correlation was demonstrated for o verall survival (p = 0.001) and recurrence free survival (p = 0.01). N o statistical significance was observed for clinical outcome and Ki-67 (overall survival p = 0.18; recurrence free survival p = 0.1). None o f the factors, TLI or Ki-67, was an independent prognostic factor as d emonstrated by multivariate analysis.