Treatment outcomes of patients (pts) with primary mediastinal germ cell tumors (PMGCT): The M. D. Anderson Cancer Center (MDACC) experience

Abstract

14538 Background: PMGCT are uncommon germ cell malignancies. Mediastinal nonseminomatous germ cell tumors (NSGCT) have a poor prognosis, whereas pure seminoma (Sem) has a good or intermediate prognosis irrespective of mediastinal presentation. Methods: We retrospectively identified 19 male pts with PMGCT seen at MDACC between October 1998 and September 2004 from a clinical database. Pts with resectable NSGCT were offered surgery upon plateau of their chemotherapy response. Prior to referral, 1 pt had primary surgical resection without preoperative (preop) chemotherapy. Results: There were 14 pts with NSGCT and 5 with good prognosis Sem. The median age was 29.5 (20–60). Seven pts with NSGCT had mixed or undifferentiated histology, and the remainder had pure yolk sac (5 pts) or choriocarcinoma (2 pts). The estimated median survival (Kaplan-Meier) for all patients (Sem + NSGCT) was 21 months. All pts with Sem were alive and disease-free at last follow-up (median 12 months, range 7–34). All pts with Sem received 4 courses of etoposide and cisplatin (EP); one also received bleomycin (BEP); one received radiotherapy consolidation; none received surgery. Of the pts with NSGCT, 9 (64%) have died, including 1 who refused surgery. Five pts with NSGCT were alive at last follow-up and 3 (21%) were disease-free (15+, 27+ and 35+ months). Four pts with NSGCT (29%) reached beyond 2 years survival (27+, 28, 35+, and 63+ months) including 3 with lung metastases and one with elevated preop alpha-fetoprotein (28,022 ng/ml). Each of these pts received 6–10 courses of multiple-regimen preop chemotherapy, and 2 received initially 4 courses of BEP without marker normalization. Conclusions: Mediastinal Sem treated with 4 courses EP had an excellent outcome without surgery. Pts with mediastinal NSGCT had a 64% mortality rate despite aggressive treatment. Several pts with mediastinal NSGCT did achieve long-term survival following aggressive chemotherapy and surgery, even with lung metastases and failure to normalize markers. A phase III trial of BEP versus dose-dense chemotherapy for poor-prognosis NSGCT is now in progress at MDACC. No significant financial relationships to disclose.