ASCO 2017: Long-term causes of relative excess mortality after diagnosis of testicular germ cell tumor

Chicago, IL ( Testicular germ cell tumors (TGCT) have excellent cure rates nowadays. However, there is a reduced long-term relative survival (RS) which is an increasing concern. A recent study showed a continuing decline in RS among these patients diagnosed in Norway, even after more than 30 years of follow-up.1 The most probable causes are the late effects of treatment. Although several reports in the literature have described increased mortality from secondary malignancies (SM), cardiovascular disease (CVD), and other causes (OC) among TGCT survivors, data beyond 25 years of follow-up are scarce. Dr. Kvammen presented a study aiming to analyze long-term relative risks (RR) and causes of death (CD) among TGCT patients diagnosed in Norway in a 60 year period between1953-2014.

The Cancer Registry of Norway and the Norwegian Cause of Death Registry were analyzed for these specific patients. All men diagnosed with TGCT in Norway during this period were included, except patients with spermatocytic seminomas. Patients were classified by cause of death, 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.

At end of follow-up, 2359 of 9390 patients (27%) were deceased. Cause of death was obtained for 2320 patients: 37.6 % TGCT, 24.5 % SM, 19.1 % CVD and 18.8 % OC. SMR for all SM 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 SM of the pancreas, large intestine and bladder. By contrast, SMR for CVD were significant among patients diagnosed during 2000-2014, 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 follow-up (2.2 – 5.1).

In conclusion, TGCT patients have increased RR of SM and OC death even after 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 during the years 2000-2014 are of particular concern. This study reinforces the past published conclusion that optimization of TGCT treatment and follow-up schemes is required, including further research on toxicity mechanisms.

Presented By: Oivind Kvammen, Trondheim, Norway

Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre
Twitter: @GoldbergHanan

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA

1. Kvammen O, Myklebust TA, Solberg A, et al. Long-term Relative Survival after Diagnosis of Testicular Germ Cell Tumor. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2016; 25(5): 773-9.