Single-agent carboplatinum for advanced seminoma. A phase II study.

Background: To reduce the side effects of cisplatin-based combination chemotherapy, the activity of carboplatinum was evaluated in patients with advanced seminoma.

Methods: Forty-two evaluable patients with advanced seminoma (defined as abdominal lymph nodes > 5 cm or supradiaphragmatic or visceral disease) received single-agent carboplatinum at a dose of 400 mg/m2 intravenously every 4 weeks for a maximum of six cycles. The median follow-up was 31 months (18-67 months).

Results: Thirty patients (71%) achieved a complete remission (CR; 21 chemotherapy alone, 9 with additional surgery), 8 patients (19%) a partial remission (PR), and 4 patients had disease progression (10%). Patients with metastases confined to the lymph nodes had a significantly higher remission rate than patients with visceral metastases (97% versus 50%; P < 0.002). Elevation of lactate dehydrogenase or human chorionic gonadotropin before radiation therapy had no influence on response rate. Eight patients have relapsed (five from CR and three from PR). All 12 patients failing carboplatinum therapy received cisplatin-based combination regimens. Ten patients achieved a stable favorable response (eight CR, two PR), whereas two patients died of their disease. Currently, 30 patients (71%) are continuously free from progression (25 CR, 5 PR), and 40 patients are alive (survival 93%). Toxicity was mild with no neurotoxicity or nephrotoxicity.

Conclusions: The use of up-front carboplatinum therapy appears not to compromise the ultimate curability of patients with advanced seminoma. Randomized trials, however, will have to demonstrate the effectiveness of carboplatinum with regard to survival, and help to identify prognostic subgroups of patients who require up-front cisplatinum-based combination chemotherapy.