Emotional, behavioral, and physical health consequences of loneliness in young adult survivors of childhood cancer: Results from the Childhood Cancer Survivor Study

Background: Young adults in the general population are at risk of experiencing loneliness, which has been associated with physical and mental health morbidities. The prevalence and consequences of loneliness in young adult survivors of childhood cancer remain unknown. Methods: A total of 9664 young adult survivors of childhood cancer (median age at diagnosis 10.5 years [interquartile range (IQR), 5–15], 27.1 years at baseline [IQR, 23–32]) and 2221 siblings enrolled in the Childhood Cancer Survivor Study completed a self-reported survey question assessing loneliness on the Brief Symptom Inventory-18 at baseline and follow-up (median follow-up, 6.6 years). Multivariable models evaluated the prevalence of loneliness at baseline only, follow-up only, and baseline + follow-up, and its associations with emotional distress, health behaviors, and chronic conditions at follow-up. Results: Survivors were more likely than siblings to report loneliness at baseline + follow-up (prevalence ratio [PR] 2.2; 95% confidence interval [CI], 1.7–3.0) and at follow-up only (PR, 1.4; 95% CI, 1.1–1.7). Loneliness at baseline + follow-up was associated with elevated risk of anxiety (relative risk [RR], 9.8; 95% CI, 7.5–12.7), depression (RR, 17.9; 95% CI, 14.1–22.7), and current smoking (odds ratio [OR], 1.7; 95% CI, 1.3–2.3) at follow-up. Loneliness at follow-up only was associated with suicidal ideation (RR, 1.5; 95% CI, 1.1–2.1), heavy/risky alcohol consumption (RR, 1.3; 95% CI, 1.1–1.5), and new-onset grade 2–4 chronic conditions (RR, 1.3; 95% CI, 1.0–1.7). Conclusions: Young adult survivors of childhood cancer have elevated risk of experiencing loneliness, which is associated with future emotional distress, risky health behaviors, and new-onset chronic conditions.