Long-term outcomes following post-operative radiotherapy for Stage I/II testicular seminoma - an Australasian single-institution experience.

INTRODUCTION: The aim of the study is to review the long-term oncological outcomes and adverse effects of post-operative radiotherapy (PORT) for Stage I/II seminoma patients in an Australian radiation treatment centre.

METHODS: This is a retrospective study of 125 patients with Stage I/II seminoma treated with PORT at the Alfred Health Radiation Oncology Service between 1992 and 2013. Patients were linked to the Victorian Cancer Registry to enable confirmation of survival and diagnosis of secondary malignancies (SM). The relapse-free survival (RFS), testicular-cancer-specific survival (TCSS), overall survival (OS) and SM-free survival (SMFS) were estimated with Kaplan-Meier methods.

RESULTS: The median age at diagnosis was 36 (range 20-62). The median time between diagnosis and PORT was 1.6 months (range: 0.5-4.5). Fifty patients (40%) had PORT to the para-aortic (PA) target alone, while the remaining had PORT to PA and ipsilateral or bilateral iliac lymph nodes. There were no acute adverse effects requiring admission. The median follow-up after PORT was 7.8 years (range = 0.1-19.1). There were two relapses, both of which occurred within 1 year of PORT (estimated 10-year RFS = 98.4%). Five deaths were reported, none of which were testicular cancer-related death (estimated 10-year TCSS = 100%, 10-year OS = 97.3%). There were seven SM (one lower lip cancer, one upper shoulder melanoma, one mesothelioma, two prostate cancer, one acute myeloid leukaemia and one contralateral testicular seminoma) reported in six patients, with estimated 10-year SMFS of 92.9%.

CONCLUSION: Our series confirms excellent oncological outcomes among patients with Stage I/II seminoma treated with PORT, with uncommon occurrence of SM.