Purpose: Carboplatin has demonstrated significantly poorer response rates in non-seminomatous germ cell tumours. A phase II study of higher than standard doses of carboplatin was conducted because of suspicion that the poorer response might have been due to suboptimal dosing.
Patients and methods: A group of 19 patients with advanced germ cell tumours (International Germ Cell Cancer Collaborative Group intermediate and poor prognosis) were treated with carboplatin at an AUC of 8 mg/ml.min (using Calvert's formula) on day 1, etoposide 120 mg/m2 days 1-3 and bleomycin 60,000 U over 2 days (EBCa). Treatment was repeated every 3 weeks and a maximum of four courses was given.
Results: Of the 19 patients, 7 (37%) achieved complete remission, of whom 6 (32%) remained long-term progression-free. Post-chemotherapy surgery and further chemotherapy salvaged an additional 26%, leading to an overall disease-free survival rate of 58%. No relationship between outcome and degree of myelosuppression could be established.
Conclusion: Dose-escalated carboplatin in combination, although feasible, did not improve the results and led to poorer results than those expected with cisplatin-based therapy. There is no evidence that the patients relapsing following this were easier to salvage. Further investigation of this regimen cannot be recommended.