Long-term Testis Cancer Survivors in Canada—Mortality Risks in a Large Population-based Cohort

BACKGROUND: Testis cancer (TC) patients are young with excellent cancer prognosis. Hence, the risk of late-onset treatment-related morbidity and mortality is of concern due to longer survival after treatment. OBJECTIVE: We set to characterize long-term survival of TC patients through a Canadian population dataset. DESIGN, SETTING, AND PARTICIPANTS: We used a population-based dataset, the Canadian Census Health and Environment Cohort (CanCHEC), to identify individuals diagnosed with TC between 1991 and 2010. We compared them with all other male individuals without TC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was mortality due to cardiovascular disease (CVD) or nontesticular malignancy. Mann-Whitney or chi-square test was used where applicable. Data were analyzed using a Cox proportional hazard model with and without matching. RESULTS AND LIMITATIONS: We identified 1950 individuals with TC. We compared them with 1 300 295 men with no TC. There were 335 deaths in the study group during the study period (17.2%) with a mean follow-up of 19.6 yr. TC patients were at increased risk of death from secondary malignancies (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.39–1.91; p < 0.0001) with specific risks for hematologic neoplasms (HR 3.86, 95% CI 2.78–5.37; p < 0.001) and other malignancies (HR 2.41, 95% CI 1.76–3.29; p < 0.001). Gastrointestinal, hematologic, and respiratory toxicities were the most common secondary malignancies leading to death. When stratified according to histology, nonseminoma (NS) patients were at significantly increased risk of death from CVD (HR 2.03, 95% CI 1.27–3.25; p = 0.0032). Individuals with seminoma were at increased risk of death from other nontestis neoplasms (HR 1.46, 95% CI 1.17–1.82; p = 0.0007), specifically hematologic neoplasms (HR 2.09, 95% CI 1.18–3.72; p = 0.0118). CONCLUSIONS: NS patients are at increased risk of CVD-related death, whereas seminoma patients are at increased risk of death from non–testis-related malignancies. PATIENT SUMMARY: We report long-term mortality following diagnosis of testis cancer. Nonseminoma patients have an increased risk of death from cardiovascular disease, while seminoma patients have an increased risk of death from secondary malignancies.