Retrospective multicentre study of carboplatin monotherapy for clinical stage I seminoma

• To evaluate, in a retrospective multicentre study, the long-term oncological efficacy and morbidity of using carboplatin as an alternative treatment for patients with clinical stage I seminoma.

• Patients with clinical stage I seminoma treated with two cycles of adjuvant single-agent carboplatin (400 mg/m² body surface) from February 1990 until September 2008 were retrospectively identified. • A database was created (including information on patient characteristics, initial tumour staging, tumour marker levels, follow-up, oncological outcome, treatment side effects and long-term side effects), descriptive analyses were performed and the data were compared with those available in the literature.

• Of 282 stage I seminomas identified in 276 patients, risk factors for progression (pT2/3, vessel invasion or tumour diameter ≥ 4 cm) were detected in 48.2% of tumours. • Chemotherapy was well tolerated, with patients experiencing only mild nausea. Bone marrow suppression was common (leucopaenia in 36.7% and thrombocytopaenia in 50.5% of patients, mainly grade 1/2). Neither neutropenic fever, nor any bleeding complication occurred. • During a mean follow-up of 75 months, three patients (1.06%) developed a retroperitoneal recurrence within the first 2 years after receiving adjuvant treatment and were salvaged by cisplatin-based chemotherapy. A contralateral second testicular germ cell tumour was diagnosed in five patients.

• Two cycles of carboplatin monotherapy are highly effective and very well tolerated by all patients. The frequency of contralateral tumours appears to be reduced. • Despite the lack of a randomized trial, the available data in the literature suggest that the administration of two cycles instead of one cycle could lead to a reduction in recurrence rates of ≈50%.