Germ cell tumors: staging, prognosis, and outcome.

Germ cell tumors (GCT) remain the model for solid tumor therapy. Until 1997, GCT staging was based on individual institution systems, which limited comparison of data and collaboration between GCT groups. GCT staging is based on four basic criteria: disease site of origin, histology, secretion of serum tumor markers (STM), and bulk of disease. Within most staging systems developed by investigators, clinical stage I disease is confined to the testis based on radiographic imaging and STM or pathological stage I based on lack of histological disease at retroperitoneal lymphadenectomy. Stages II and III are considered to be disease outside the testis categorized by lymphatic spread to the retroperitoneal lymph nodes or hematological spread to lungs and visceral organs, respectively. The major staging systems previously used include the Indiana University Staging System; Modified Samuels' Classification (M.D. Anderson Cancer Center); Memorial Sloan Kettering Cancer Center Mathematical Model; and the Tumor, Nodal, Metastases (TNM) Staging System (American Joint Committee on Cancer). The most recent evolution in staging systems is the 1997 International Germ Cell Consensus Classification, which is based on prognosis and outcomes. This system allows for comparison of data and collaboration between Germ Cell Tumor Groups.