KI-67 AND PROLIFERATING CELL NUCLEAR ANTIGEN TUMOR PROLIFERATIVE INDEXES IN DNA DIPLOID COLORECTAL ADENOCARCINOMAS - CORRELATION WITH HISTOPATHOLOGIC CHARACTERISTICS AND CELL-CYCLE ANALYSIS WITH 2-COLOR DNA FLOW-CYTOMETRY

The prognostic significance of tumor proliferative activity (TPA) in c olorectal adenocarcinomas (CA) determined by proliferating cell nuclea r antigen (PCNA) and Ki-67 staining is not well defined. Previous inve stigations of TPA using Ki-67 immunohistologic studies and flow cytome tric (FCM) analysis have found no correlation with conventional histop athologic parameters. To better define the relationship of these vario us TPA measurements in CA, the authors selected 46 tumors with diploid DNA content previously analyzed by two-color DNA FCM analysis of fres h specimens to more effectively assess actual S-phase fractions (SPFs) from cytokeratin-gated DNA histograms for comparison with the followi ng: (1) immunohistologic Ki-67 and PCNA tumor proliferation indices (T PIs); and (2) conventional histopathologic observations of prognostic import. These data show no significant correlation coefficient between Ki-67 or PCNA TPIs and SPFs derived from FCM analysis; however, the D NA diploid tumor subset categorized as having a greater than median SP F value had a significantly higher mean Ki-67 but not PCNA proliferati on index. There was no correlation of any measure of proliferation wit h any of the eight histopathologic features of known prognostic signif icance.