Adjuvant carboplatin therapy in patients with clinical stage 1 testicular seminoma: is long-term morbidity increased?

Purpose: Clinical stage (CS) 1 testicular seminoma is cured in almost 100% of cases following either retroperitoneal radiotherapy, carboplatin monotherapy, or surveillance strategies. Little is known about potential long-term effects of carboplatin. We, therefore, examined late sequelae of this drug in seminoma patients.
Patients and Methods: We retrospectively identified 451 patients with CS1 testicular seminoma treated between 1994 and 2014, of whom 243 underwent carboplatin therapy [median follow-up (F/U) 96 months], 81 received radiotherapy (median F/U 142 months), and 127 underwent surveillance (median F/U 40 months). Satisfaction regarding management, as well as the following events during F/U, were analysed by questionnaire: subsequent malignant neoplasms (SMNs), cardiovascular events, arterial hypertension, peptic ulcer, tinnitus, peripheral neuropathy, hypogonadism, and infertility. The relative frequencies of the events were analysed using descriptive statistics. The frequency of observed SMNs was compared with the expected number.
Results: Patients receiving carboplatin tolerated the treatment less well (71.2%) than those under surveillance (81.9%). After carboplatin, 12 SMNs (5.0%) were noted vis-a-vis 5.0 expected. There were three cases of prostatic cancer and 3 melanomas among the SMNs. Half of these SMNs occurred early after treatment. Among the other health events, only reported hypogonadism (13.2%) appeared to be marginally increased in frequency.
Conclusions: This study found a 2.4-fold higher than expected rate of SMN-and a slightly increased rate of hypogonadism-in the long-term period following carboplatin treatment. Although further studies are needed to confirm these preliminary findings, these results are probably informative for clinicians caring for seminoma patients.