Hospitalization Rates Among Long-Term Survivors of Childhood Leukemia and Lymphoma: A Report From the Childhood Cancer Survivor Study (CCSS).
Authors: Nolan Vikki G , Kurt Beth , Ness Kirsten K , Neglia Joseph P. , Tersak Jean , Hudson Melissa M. , Armstrong Gregory , Leisenring Wendy , Robison Leslie L. , Arora Mukta 
Published: October 2019

Abstract
Abstract 4633

Background
Chronic health conditions are commonly reported by survivors of childhood leukemia and lymphoma. To further understand the socio-economic impact of these reported conditions, we sought to determine overall and cause-specific rates of hospitalization among survivors of childhood leukemia/lymphoma and to compare these rates with those of the U.S. population.

Methods
From the CCSS, 5,637 5 year survivors of childhood leukemia/lymphoma, who participated in the 2000 follow-up questionnaire, were identified. Data related to hospitalizations occurring during the years 1992-2005 were collected and hospitalization rates among survivors were determined. For comparison, hospitalization rates in the general U.S. population were obtained from the National Hospital Discharge Survey (NHDS). Indirect standardization was used to calculate age- and sex- standardized incidence ratios (SIR) and absolute excess risks (AER). The reasons for hospitalization were described and cause specific hospitalization rates were also compared with those of the general U.S. population.

Results
At follow up, the mean age was 29.2 years (SD: 7.6; range: 14.0-51.0) and the mean time since diagnosis was 20.8 years (SD: 4.6; range 13.3-31.7). Overall, the hospitalization rates of survivors of childhood leukemia, non-Hodgkin lymphoma (NHL) and Hodgkin disease (HD) were 1.3 (95% CI: 1.2-1.3), 1.2 (95% CI: 1.1, 1.3) and 1.9 times (95% CI: 1.8, 2.0) that of the general U.S. population, respectively. Survivors, regardless of diagnosis, were more likely than the general population to be hospitalized for infection, endocrine, cardiovascular, gastrointestinal and genitourinary reasons, as well as external causes (Figure 1). The greatest AER was associated with hospitalization for neoplasm. Survivors of leukemia and NHL were approximately 5 times [SIRleukemia: 5.4 (95% CI: 4.8; 6.2) and SIRNHL: 4.8; (95% CI: 3.6, 6.1)] and HD survivors 10.2 times (95% CI: 8.9, 11.7) more likely than the general population to be hospitalized for this reason. Survivors of HD had 6.5 times (95%CI: 5.6, 7.5) the rate of hospitalization for cardiovascular causes and 4.4 times (95% CI: 3.6, 5.2) the rate of hospitalization for pulmonary causes when compared with the general U.S. population. These findings are consistent with reports indicating an increased risk for second cancers, particularly breast cancer after chest irradiation, and conditions such as pneumonitis, lung fibrosis, cardiomyopathy and coronary artery disease among Hodgkin patients. Survivors of leukemia had 5.2 times (95% CI: 4.4, 6.2) the rate of hospitalization for neurological reasons compared with the general population, likely reflecting late effects of treatment with cranial and spinal radiation. Interestingly, survivors have a significantly lower rate of hospitalization for psychological reasons when compared with the U.S. population (Figure 1).

Conclusions
Long-term survivors of childhood leukemia/lymphoma experience a significantly increased rate of hospitalization. Additional research is needed to further quantify the overall healthcare utilization and economic impact of treatment-related complications as this population ages. These findings also emphasize the importance of ongoing medical surveillance that includes screening and prevention strategies, which may impact the occurrence of serious medical conditions resulting in hospitalization.

Disclosures:
No relevant conflicts of interest to declare.