Long-term causes of relative excess mortality after diagnosis of testicular germ cell tumor.

4553 Background: Despite today’s excellent cure rates among testicular germ cell tumor (TGCT) patients, reduced long-term relative survival (RS) is an increasing concern. We recently reported a continuing decline in RS among TGCT patients diagnosed in Norway, even beyond 30 years of follow-up. Late effects of treatment is the main culprit. Although several reports describe increased mortality from second cancer (SC), cardiovascular disease (CVD), and other causes (OC) among TGCT survivors, data beyond 20 years of follow-up are scarce. The study aim was to analyze long-term relative risks (RR) and causes of death (CD) among TGCT patients diagnosed in Norway, 1953-2014. Methods: Data sources were the Cancer Registry of Norway and the Norwegian Cause of Death Registry. All men diagnosed with TGCT in Norway during 1953-2014 were included, except spermatocytic seminomas. End of follow-up was December 31st, 2014. Patients were classified by CD, histology, disease extent and age at diagnosis, as well as by decade of diagnosis and follow-up time. Standardized mortality ratios (SMR), compared with the general Norwegian male population, were computed. Results: At end of follow-up, 2359 of 9390 patients were deceased. CD was obtained for 2320 patients; 37.6 % TGCT, 24.5 % SC, 19.1 % CVD and 18.8 % OC. SMR for all SC were significant particularly after 20 years of follow-up (1.8 – 3.1), with similar findings in localized disease at diagnosis. SMR were most consistently elevated beyond 20-30 years for SC of the pancreas, large intestine and bladder. By contrast, SMR for CVD were significant among patients diagnosed 2000-14, both before and after one year of follow-up (2.6). There were no significant SMR for CVD beyond 20 years of follow-up. Several OC SMR were elevated, such as for digestive and genitourinary diseases beyond 20-30 years (2.2 – 5.1). Conclusions: TGCT patients have increased RR of SC and OC death even beyond 20-30 years of follow-up, while the increased RR of CVD death is mostly confined to the first decade. CVD deaths in patients diagnosed 2000-14 are a particular concern. Continuing optimization of TGCT treatment and follow-up schemes is required, including further research on toxicity mechanisms.