Disease-specific hospitalizations among 5-year survivors of Wilms tumor: A Nordic population-based cohort study

Background: With modern therapy, over 90% of Wilms tumor patients can expect to become long-term survivors, and focus on morbidity and late effects become increasingly important. We provide a novel evaluation and insight to subsequent hospitalizations in 5-year survivors of Wilms tumor. Methods: As part of the Adult Life after Childhood Cancer in Scandinavia (ALiCCS) study, we identified 5-year survivors of Wilms tumor. Based on stratified random sampling, we constructed a population comparison cohort. Outcomes of interest were overall hospitalizations; hospitalizations for specific organ systems and disease-specific categories. Standardized hospitalization rate ratios (SHRR) and absolute excess risks (AER) were calculated. Results: We included 913, 5-year survivors of Wilms tumor and 152 231 population comparisons. Survivors of Wilms tumor had an increased overall risk of being hospitalized (SHRR 1.8; 95% confidence interval (CI) 1.7-2.0). The hospitalization risk was increased within all major organ systems: urinary and genital organs (SHRR 2.5; 95% CI 2.1-3.0), endocrine (SHRR 2.5; 95% CI 1.9-3.3), cardiovascular (SHRR 2.2; 95% CI 1.7-2.9), and gastrointestinal (SHRR 1.5; 95% CI 1.3-1.8). Risks for specific diseases are reported in the study. Conclusions: Survivors of Wilms tumor had higher risks than population comparisons for a wide range of diseases, with the highest risks seen for urinary, endocrine, and cardiovascular disorders. Five to 20 years after the Wilms tumor diagnosis, 43% of survivors had been hospitalized at least once versus 29% of population comparisons. The overall AER was 2.3, which translates into 0.2 extra hospitalizations in 10 years for every Wilms tumor survivor.