Late relapse of stage i seminoma following single-agent carboplatin

We present a case report of a patient who received adjuvant carboplatin for stage 1 seminoma and relapsed with abdominal lymph node metastasis at 48 months. In recent years, many oncologists have offered a single cycle of adjuvant carboplatin AUC7 as adjuvant treatment for stage 1 seminoma. The available data show a non-inferior relapse-free survival at 3 years compared with para-aortic radiotherapy. The rate of relapse beyond this point has not been reported. Patients with stage 1 seminoma represent a group of patients with excellent outcomes, and treatment options must also consider the late effects of treatment, of which there are increasing data of mortality for those treated with radiotherapy. Patients who opt for surveillance have a greater than 80% chance of remaining relapse free at 5 years, but those on surveillance require more CT examinations for follow-up. For those treated with single-agent carboplatin, our case report highlights that late relapse can occur, and we suggest that CT surveillance beyond 2 years is required given the lack of mature data on late relapse.