Long-term Relative Survival after Diagnosis of Testicular Germ Cell Tumor.

BACKGROUND: Long-term relative survival (RS) data for testicular germ cell tumor (TGCT) patients are scarce. We aimed to analyze long-term RS among TGCT patients diagnosed in Norway, between 1953 and 2012.

METHODS: Data sources were the Cancer Registry of Norway and the Norwegian Cause of Death Registry. TGCT patients diagnosed during 1953 to 2012 were classified by time of diagnosis, histology, age, and disease extent at diagnosis. Estimates for RS were obtained, and a test comparing overall RS was performed. Corresponding data were obtained for men diagnosed with localized malignant melanoma before age 50.

RESULTS: A total of 8,736 TGCT patients were included. RS generally continued to decline with increasing follow-up time, particularly beyond 15 to 30 years, unlike in localized malignant melanoma. Although RS was generally higher for seminomas, the continuing decline was more pronounced than for nonseminomas, even when diagnosed with localized disease. TGCT patients diagnosed before 1980 or after age 40 had lower RS.

CONCLUSIONS: Although TGCT RS has improved in recent decades, it continues to decline even beyond 30 years of follow-up, regardless of disease extent at diagnosis. The main cause is probably treatment-induced late effects, particularly affecting seminoma patients. The continued use of adjuvant radiotherapy in seminomas until year 2000 is suspected as a culprit.

IMPACT: Long-term TGCT survivors should be closely monitored for the development of late comorbidity. The challenge is to reduce negative consequences of previous and current TGCT treatment on RS while maintaining the excellent cure rates. Further research on causes of long-term morbidity and mortality among TGCT survivors is warranted. Cancer Epidemiol Biomarkers Prev; 25(5); 773-9. ©2016 AACR.