Long-term Risk of Hospitalization for Somatic Diseases in Survivors of Adolescent or Young Adult Cancer

IMPORTANCE Survivors of adolescent and young adult cancers are at risk for treatment-induced late adverse effects; however, to our knowledge, the long-term risk of hospitalization in this specific group of cancer survivors has not been thoroughly evaluated. OBJECTIVE To examine relative and absolute excess risk for hospitalizations up to 34 years after diagnosis of adolescent and young adult cancer compared with population comparisons. DESIGN, SETTING, AND PARTICIPANTS This was a cohort study, conducted in Denmark, of 33 555 five-year survivors of adolescent or young adult cancer, diagnosed from 1943 through 2004, when they were 15 to 39 years of age, and 228 447 population comparisons, matched to the survivors by sex and year of birth. MAIN OUTCOMES AND MEASURES Cancer survivors and comparisons were followed up for hospitalizations in the Danish Patient Register through December 2010. Standardized hospitalization rate ratios (RRs) and absolute excess risks (AERs) were calculated. RESULTS After a median follow-up of 14 years, we identified 53 032 hospitalizations in cancer survivors, whereas 38 423 were expected, resulting in an overall RR of 1.38 (95% CI, 1.37-1.39). The data analysis was started in January 2015 and ended in June 2015. Additional data analyses requested by the reviewers were conducted in August 2015. The highest risks were found for the main diagnostic groups of diseases of blood and blood-forming organs (RR, 2.00; 95% CI, 1.87-2.14), infectious and parasitic diseases (RR, 1.69; 95% CI, 1.61-1.77), and malignant neoplasms (RR, 1.63; 95% CI, 1.59-1.68). The overall AER was 2803 (95% CI, 2712-2893) per 100 000 person-years; the highest AERs were found for malignant neoplasms, diseases of digestive organs, and diseases of the circulatory system (18%, 15%, and 14% of total AER, respectively). Survivors of the 10 most common cancers in adolescents and young adults were at significantly increased risk for diseases in the 12 main diagnostic groups. The highest risks were those of survivors of leukemia (RR, 2.21; 95% CI, 2.02-2.42), brain cancer (RR, 1.93; 95% CI, 1.86-2.00), and Hodgkin lymphoma (RR, 1.87; 95% CI, 1.80-1.94). CONCLUSIONS AND RELEVANCE The large number of survivors and the use of hospital discharge diagnoses made it possible to draw a comprehensive picture of the complex inpatient disease burden experienced by survivors of adolescent and young adult cancer. The findings underscore a great diversity of cancer-related health problems that physicians and patients should be knowledgeable about.