Adjuvant Carboplatin Treatment in 115 Patients With Stage I Seminoma: Retrospective Multicenter Survey.

BACKGROUND: The administration of carboplatin AUC 7 has become a standard adjuvant option for patients undergoing orchiectomy for stage I seminoma, in alternative to radiotherapy on retroperitoneal lymphnodes or surveillance. The toxicity of AUC 7 carboplatin appeared manageable in the pivotal trial of Oliver et al, but dose ranges were not reported. Fear of toxicity may induce arbitrary dose reductions, which may potentially compromise patients' outcome.

PATIENTS AND METHODS: We reviewed adjuvant carboplatin administration in 115 stage I seminoma patients followed in 11 Italian medical oncology centers since 2005. Clinical and pathological data, modality of carboplatin dose calculation, dose reductions, toxicities, and relapses were recorded.

RESULTS: Median age was 35 years (range, 18-65 years), adverse prognostic factors were either T ≥ 4 cm (17.4%) or rete testis invasion (28.7%), both of them (35.7%), none or unspecified (18.3%). GFR was estimated mainly by Cockroft-Gault formula (55.7%) or Jeliffe formula (26.1%), with a median of 105 mL/min (range, 75-209 mL/min). The median dose of carboplatin was 900 mg (range, 690-1535 mg). A dose reduction > 10% was applied to 14 patients. Toxicities were mild fatigue, moderate nausea/vomiting, 5.2% of grade 3 to 4 thrombocytopenia. After a median follow-up of 22.1 months, 5.2% of patients have relapsed in the retroperitoneal lymph nodes. None of the patients that relapsed were treated with reduced dose. All but one achieved complete remission with salvage chemotherapy.

CONCLUSIONS: Adjuvant AUC 7 carboplatin reduce relapses of stage I seminoma patients to 5.2%, with manageable toxicities. Dose reductions should be proscribed.