Outcome of Men With Relapse After Adjuvant Carboplatin for Clinical Stage I Seminoma.

Purpose Adjuvant carboplatin is one of three management strategies that may follow inguinal orchiectomy in clinical stage I seminoma. However, little is known about the outcome of patients who experience a relapse after such treatment. Patients and Methods Data from 185 patients who relapsed after adjuvant carboplatin between January 1987 and August 2013 at 31 centers/groups from 20 countries were collected and retrospectively analyzed. Primary outcomes were disease-free survival and overall survival. Secondary outcomes were time to, stage at, and treatment of relapse as well as rate of subsequent relapses. Results With a median follow-up of 53 months (95% CI, 48 to 60 months) the 5-year disease-free survival was 82% (95% CI, 77% to 89%), and the 5-year overall survival was 98% (95% CI, 95% to 100%). The median time from orchiectomy to relapse was 19 months (95% CI, 17 to 23 months); 15% (95% CI, 10% to 21%) of relapses occurred > 3 years after treatment. The majority of relapses were detected by computed tomography scan during routine follow-up, 98% in the International Germ Cell Cancer Collaborative Group good prognosis group. Chemotherapy was administered to 92% of patients, mostly as standard first-line treatment corresponding to stage; 8% of patients had additional local treatments. Only 28 patients experienced a second relapse. At last follow-up, 174 (94%) of 185 patients were alive without disease, and four patients with disease. Seven patients died, three of whom due to progressive disease. Conclusion Within the limitations of a retrospective analysis, the results suggest that the majority of patients who experience a relapse after adjuvant carboplatin for clinical stage I seminoma can be successfully treated with a cisplatin-based chemotherapy regimen adequate for stage. Because 15% of the relapses occurred > 3 years after adjuvant treatment, a minimum of 5 years follow-up is recommended.