Somatic late effects in 5-year survivors of neuroblastoma: a population-based cohort study within the Adult Life after Childhood Cancer in Scandinavia study

Because of the rarity of neuroblastoma and poor survival until the 1990s, information on late effects in neuroblastoma survivors is sparse. We comprehensively reviewed the long-term risk for somatic disease in neuroblastoma survivors. We identified 721 5-year survivors of neuroblastoma in Nordic population-based cancer registries and identified late effects in national hospital registries covering the period 1977-2012. Detailed treatment information was available for 46% of the survivors. The disease-specific rates of hospitalization of survivors and of 152,231 randomly selected population comparisons were used to calculate standardized hospitalization rate ratios (SHRRs) and absolute excess risks (AERs). During 5,500 person-years of follow-up, 501 5-year survivors had a first hospital contact yielding a SHRR of 2.3 (95% CI 2.1-2.6) and a corresponding AER of 52 (95% CI 44-60) per 1,000 person-years. The highest relative risks were for diseases of blood and blood-forming organs (SHRR 3.8; 95% CI 2.7-5.4), endocrine diseases (3.6 [3.1-4.2]), circulatory system diseases (3.1 [2.5-3.8]), and diseases of the nervous system (3.0 [2.6-3.3]). Approximately 60% of the excess new hospitalizations of survivors were for diseases of the nervous system, urinary system, endocrine system, and bone and soft tissue. The relative risks and AERs were highest for the survivors most intensively treated. Survivors of neuroblastoma have a highly increased long-term risk for somatic late effects in all the main disease groups as compared to background levels. Our results are useful for counseling survivors and should contribute to improving health care planning in post-therapy clinics.