Neoadjuvant carboplatin before radiotherapy in stage IIA and IIB seminoma

Extended field radiotherapy is a standard of care for low volume stage II testicular seminoma. We hypothesized that neoadjuvant carboplatin might reduce the recurrence risk. In a single-arm study, 51 patients were treated between May 1996 and November 2011 with a single cycle of carboplatin followed by radiotherapy. The radiation field was reduced from an extended abdomino-pelvic field to just the para-aortic region, and the radiation dose from 35 Gy to 30 Gy in 39 patients. After a median follow-up of 55 months (range 8-151 months) with 38 (74%) of the patients having been followed for > 2 years, there have been no relapses (95% confidence limits of 5-year relapse-free survival of 93%-100%). Toxicity has been low with grade 3 toxicity limited to four patients with grade 3 haematological toxicity (with no clinical sequelae) and one patient with grade 3 nausea (during radiotherapy). No patients experienced grade 4 toxicity. The results of this pilot study suggest that a single cycle of neoadjuvant carboplatin before radiotherapy may reduce recurrence risk compared with radiotherapy alone and permit a smaller radiation field, and this approach is proposed for further investigation.