Prognostic significance of a novel proliferation marker, anti-repp 86, forendometrial carcinoma: A multivariate study

Traditional prognostic factors often fail to identify a subgroup of endomet rial carcinoma (EC) patients with an apparently paradoxical poor outcome. W e therefore analyzed tumor cell proliferation immunohistochemically in a se ries of 164 endometrial carcinomas (EC) and compared its prognostic impact with that of the standard prognostic factors patient age, FIGO stage, FIGO grading, and histopathologic subtype. In addition to the established prolif eration markers Ki-S5 (Ki-67) and Ki-S4 (topoisomerase II alpha), we used a novel monoclonal antibody (MAb), anti-repp 86, which binds to a recently d escribed proliferation-specific protein (p86) expressed exclusively in the S, G(2), and M phases of the cell cycle, anti-repp 86, Ki-S4, and Ki-S5 imm unoreactive labeling indices (LI) correlated significantly with FIGO stage, FIGO grade, and myometrial invasion, but not with histopathologic subtype. By univariate analysis, conventional prognostic factors and proliferation indices were all predictive of disease-related mortality. A multivariate Co x regression analysis selected anti-repp 86 LI (P = .002), FIGO stage (P = .02), and histopathologic type as significant prognosticators of recurrence ; anti-repp 86 LI (P = .001) and histopathologic type (P = .0106) also emer ged as relevant predictors of mortality. A hierarchical forward regression model with the conventional prognosticators entered first and with anti-rep p 86 entered next showed that anti-repp 86 and histopathologic subtype were the superior independent prognostic indicators for an increased risk of re currence and cancer-related death. We conclude that the evaluation of anti- repp 86 immunostaining is an easily performable and exceptionally reliable method for identifying EC patients with adverse prognosis. (C) 1999 by W.B. Saunders Company.