Immunohistochemical assessment of p170 provides prognostic information in endometrial carcinoma

To determine the significance of proliferative activity (PA) in endometrial carcinomas, we analysed the expression of cell cycle-related antigens in routinely processed tissue.

Serial sections of 164 endometrial carcinoma specimens were immunostained with the monoclonal antibodies (MoAb) Ki-S4 (specificity for p170) and Ki-S5 (specificity for p320/350). The Ki-S4 PA (median value 18.3%) and Ki-S5 PA (median value 25.0%) in endometrial carcinomas showed a significant correlation (r = 0.89, P < 0.001). A significantly lower median value of Ki-S4 and Ki-S5 immunoreactivity was ascertained in endometrial carcinomas stage I vs. > I (P < 0.05), in tumours with myometrial invasion < or = 50% vs. > 50% (P < 0.03), and in grade 1 vs. grade 2 and 3 tumours (P < 0.001). Univariate analysis showed that age, FIGO stage and grade, histopathological subtype, myometrial invasion, Ki-S4 and Ki-S5 PA provided prognostic information on the adjusted overall survival, whereas FIGO stage (P = 0.002) and Ki-S4 PA (P = 0.008) were independent prognosticators for adjusted overall survival in multivariate analysis.

The association with established prognosticators for endometrial carcinomas, and the results of uni- and multivariate analysis indicates that the additional evaluation of Ki-S4 PA is useful for classifying patients into subgroups with low and high risk of relapse which might help individualizing the therapeutic strategy in endometrial cancer patients.