Patients presenting with stage I seminoma who received a single cycle of adjuvant carboplatin following inguinal orchidectomy have an excellent prognosis, a new study published online ahead of print in the journal Annals of Oncology has shown.
For the retrospective analysis, researchers identified 517 patients with stage I testicular seminomatous germ cell tumor who received one cycle of adjuvant carboplatin South Central England between 1996 and 2013.
Results showed that with a median follow-up of 47.2 months, the 5-year estimated relapse-free survival was 95.0% (95% CI: 92.8, 97.3). In the 21 patients that relapsed, the median time to relapse was 22.7 months. Only four patients experienced a relapse beyond 3 years and 95% of relapsed patients had retroperitoneal lymph node metastases.
Researchers found that 76% of those that relapsed had elevated tumor markers at the time of relapse. Nearly 4% of all patients developed a new contralateral testicular germ cell cancer.
The findings suggest that increasing tumor size is associated with an increased risk of post-chemotherapy relapse.
Following inguinal orchidectomy, management options for patients with stage I seminoma include initial surveillance or treatment with adjuvant radiotherapy or chemotherapy. The anticipated relapse rate for patients followed by surveillance alone is approximately 15%, with adjuvant treatment this risk is reduced to approximately 4-5% at five years.