The long-term risks of adjuvant carboplatin treatment for stage I seminoma of the testis

Background: The use of adjuvant carboplatin in the management of stage I seminoma of the testis has been limited by the lack of long-term data. In this study, we address this issue for the first time. Patients and methods: Data on 199 patients treated with single-agent carboplatin for stage I seminoma of the testis were prospectively collected. Overall mortality, deaths from circulatory disease and the incidence of second cancers were compared with expected values derived from the UK general population. Results: The median follow-up for the cohort was 9.0 years (range 0.1-20.1). There has been no excess in overall mortality [standardised mortality ratio (SMR) 0.89; 95% CI 0.36-1.83], death from circulatory diseases (SMR 1.44; 95% CI 0.39-3.69) or the incidence of second nontestis cancers (standardised incidence ratio 0.96; 95% CI 0.26-2.45) in this group of patients. These findings also applied to specific follow-up periods of > 5 or 10 years. Specifically, neither haematological nor solid nontestis tumours occurred in excess. There was an increase in the long-term development of contralateral testis cancers. Conclusions: This study addresses some of the concerns surrounding the long-term safety of single-agent carboplatin. It also helps in planning long-term follow-up for patients receiving this form of treatment.