Cluster Analysis of p53 and Ki67 Expression, Apoptosis, Alpha-Fetoprotein, and Human Chorionic Gonadotrophin Indicates a Favorable Prognostic Subgroup Within the Embryonal Carcinoma Germ Cell Tumor

Purpose: The prognostic information provided by alpha-fetoprotein and human chorionic gonadotrophin in the management of germ cell tumor (GCT) patients is a biochemical reflection of tumor differentiation. Ki67, p53, and apoptosis have been found to be related to proliferation (Ki67), cell death (p53, apoptosis), and possibly differentiation chemoresistance (p53). We sought to determine whether simultaneous expression of one or more of these markers could identify clinically relevant subgroups of patients with nonseminomatous GCT (NSGCT). Patients and Methods: These five marker values were obtained for 95 previously untreated patients with embryonal carcinoma with or without other germ cell components. A multivariate cluster analysis was performed to identify patients with similar marker patterns. Results: One prominent cluster (n = 37; 36 testis retroperitoneum), consisting of 26 (70%) good-risk (GR), nine (24%) intermediate-risk (IR), and two (6%) poor-risk (PR) patients, as defined by the International...