Background: The objectives of this study were to evaluate the long term outcome of patients with extragonadal seminomatous germ cell tumors (GCT) so that prognostic variables for disease recurrence and patient survival could be identified and to access the efficacy of different treatment modalities.
Methods: Six hundred thirty-five patients with extragonadal GCT who were treated consecutively at 11 centers in the United States and Europe during the cisplatin-based chemotherapy era between 1975 and 1996 were evaluated retrospectively.
Results: Fifty-two patients with primary retroperitoneal GCT (50%) and 51 patients with primary mediastinal GCT (49%) of pure seminomatous histology were identified (n = 1 patient with a primary cervical lymph node) representing 16.4% of 635 patients with extragonadal GCT who were included in the data base. The median age was 37 years (range, 18-70 years). Treatment consisted of platin-based chemotherapy in 77 patients (74%), radiotherapy in 9 patients (9%), and combined modality in 18 patients (17%). Ninety-two percent of patients (95% confidence interval, 87-97%) achieved a favorable response to primary therapy. After a median follow-up of 61 months (range, 1-211 months), 18 patients (17%) have had recurrent disease: 14% of those who received chemotherapy and 67% of those who received radiation therapy. The 5-year progression free survival rate favored the chemotherapy group, with 87% compared with 33% for irradiated patients (P = 0.006), whereas the overall survival rates were equal (90% vs. 67%; P = 0.13). No differences in overall survival or progression free survival were observed among patients with primary retroperitoneal and mediastinal seminoma. Prognostic factors that were identified to influence survival negatively were liver metastases (P = 0.01) and two or more metastatic sites (P = 0.04).
Conclusions: In patients with extragonadal seminoma, a survival rate of > 90% at 5 years is achieved with adequate cisplatin-based chemotherapy. Compared with patients with nonseminomatous extragonadal GCT, no difference in long term survival exists between patients with primary retroperitoneal or mediastinal seminoma location. Primary radiotherapy seems to be associated with a significantly higher rate of disease recurrence, although most patients will be salvaged by subsequent chemotherapy.
Copyright 2001 American Cancer Society.