Abstract
OBJECTIVE: To characterize the prevalence and predictors of concerns regarding future health and cancer risk among siblings of childhood cancer survivors. METHODS: This study reports longitudinal data (baseline and follow-up) from 3969 adult siblings (median age = 29 [range 18-56] years) of long-term survivors of childhood cancer (median time since diagnosis 19.6 [9.6-33.8] years). Self-reported future health and cancer risk concerns (concerned vs not concerned) were assessed. Demographics and health data reported by both the siblings and their matched cancer survivors were examined as risk factors for health concerns using multivariable logistic regression. RESULTS: Percentage of siblings reporting future health and cancer risk concerns, respectively, decreased across decade of survivors' diagnosis: 1970s (73.3%; 63.9%), 1980s (67.2%; 62.6%), and 1990s (45.7%; 52.3%). Risk factors associated with future health concerns included sibling chronic health conditions (grade 2 Odds Ratio [OR]=1.57, 95% CI: 1.12-2.20; grades 3-4 OR=1.86, 95% CI: 1.18-2.94; compared to less than grade 2). Risk factors associated with future cancer concerns included sibling chronic health conditions (grade 2 OR=1.43, 95% CI: 1.05-1.94; grades 3-4 OR=1.64, 95% CI: 1.09-2.47; compared to less than grade 2). CONCLUSIONS: Sibling concerns regarding future health and cancer have diminished in recent decades. There are subgroups of siblings that are at-risk for future health and cancer risk concerns. IMPLICATIONS FOR CANCER SURVIVORS: Routine screening of concerns in at-risk siblings of survivors of childhood cancer may benefit the siblings of cancer survivors. These individuals may benefit from early interventions during diagnosis and treatment of their siblings.