Immunohistochemical assessment of p170 provides prognostic information in endometrial carcinoma

Aims: To determine the significance of proliferative activity (PA) in endom etrial carcinomas, we analysed the expression of cell cycle-related antigen s in routinely processed tissue. Methods and results: Serial sections of 164 endometrial carcinoma specimens were immunostained with the monoclonal antibodies (MoAb) Ki-S4 (specificit y for p170) and Ki-S5 (specificity for p320/350). The Ki-S4 PA (median valu e 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 med ian value of Ki-S4 and Ki-S5 immunoreactivity was ascertained in endometria l carcinomas stage I vs.>I (P < 0.05), in tumours with myometrial invasion less than or equal to 50% vs. > 50% (P<0.03), and in grade 1 vs, grade 2 an d 3 tumours (P<0.001). Univariate analysis showed that age, FIGO stage and grade, histopathological subtype, myometrial invasion, Ki-S4 and Ki-S5 PA p rovided prognostic information on the adjusted overall survival, whereas FI GO stage (P = 0.002) and Ki-S4 PA (P = 0.008) were independent prognosticat ors for adjusted overall survival in multivariate analysis. Conclusions: The association with established prognosticators for endometri al carcinomas, and the results of uni- and multivariate analysis indicates that the additional evaluation of Ki-S4 PA is useful for classifying patien ts into subgroups with low and high risk of relapse which might help indivi dualizing the therapeutic strategy in endometrial cancer patients.