Indian Journal of Medical & Paediatric Oncology

Prognosis of patients with stage I seminoma is excellent with cure rate of approx 80% with high inguinal orohidectomy alone. Surveillance studies show that 15–20% of patients have occult metastatic disease mainly in the para-aortic lymph nodes.¹ Till date radiotherapy to the para-aortic + pelvic nodes (dog-leg portal) or para-aortic nodes (para-aortic portal) at a dose of 20 Gys in 10 fractions has been considered as standard adjuvant therapy for stage I Seminoma.² However, non randomized trials have shown that chemotherapy with single agent carboplatin may also be beneficial in this setting. This multicentric randomized control trial conducted by Medical Research Council (MRC) and European Organisation for Research and Treatment of Cancer (EORTC) compares a single dose of carboplatin at a dose of AUC (area under curve) 7 with radiotherapy in patients with stage I seminoma. Patients who had pT₁-pT₃N_oM_o seminoma with normal β-HCG levels post orchidectomy were included in this study. The patients were randomized to receive radiotherapy either 30Gy or 20Gy at the time of study initiation (the exact dose of radiotherapy was not known) or one course of single agent carboplatin AUC = 7. The ratio of randomization was 2.5 (30Gy radiotherapy): 2.5 (20Gy radiotherapy): 3.0 (chemotherapy). The primary end point was relapse free rate. Secondary end points were incidence of second cancers (both germ cell and non germ cell cancers), morbidity of treatment and quality of life issues. The study was powered at 85% to detect an absolute difference of 4%. Patients were stratified at randomization by center, previous inguinal pelvic or scrotal surgery and intended radiotherapy schedule.

Between September 1996 and March 2001, 1477 patients from 70 hospitals in 14 countries were randomly assigned to radiotherapy or 1 course of carboplatin. Their baseline characteristics were similar in both groups. The median follow up was four years with 91% patients having at least 2 years of follow up recorded. The relapse-free rates were similar between the two groups: 95.9% (Confidence interval 94.4 – 97.1) is radiotherapy group versus 94.8% (Confidence interval 92.5–96.4) chemotherapy arm at 3 years. P = 0.32. There was one treatment related death in the Radiotherapy group and none in the carboplatin group. Patients receiving carboplatin relapsed more frequently in the para-aortic nodes than those receiving radiotherapy (74% vs 9%). The incidence of second germ cell tumors in the contralateral testis was more in the radiotherapy group: 5 years event rate 1.96% vs 0.54% p = 0.04. Patients given carboplatin were less lethargic and less likely to take time off work than those given radiotherapy. The FSH and serum testosterone levels done before treatment and at 24 months after treatment in all patients was not different between the two groups. Grade 3 and 4 thrombocytopenia was more in the carboplatin group but there was no increased risk of bleeding.