Impact of exercise on psychological burden in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study

Background Childhood cancer survivors are at risk for adverse psychological outcomes. Whether exercise can attenuate this risk is unknown. Methods In total, 6199 participants in the Childhood Cancer Survivor Study (median age, 34.3 years [range, 22.0-54.0 years]; median age at diagnosis, 10.0 years [range, 0-21.0 years]) completed a questionnaire assessing vigorous exercise and medical/psychological conditions. Outcomes were evaluated a median of 7.8 years (range, 0.1-10.0 years) later and were defined as: symptom level above the 90th percentile of population norms for depression, anxiety, or somatization on the Brief Symptom Inventory-18; cancer-related pain; cognitive impairment using a validated self-report neurocognitive questionnaire; or poor health-related quality of life. Log-binomial regression estimated associations between exercise (metabolic equivalent [MET]-hours per week(-1)) and outcomes adjusting for cancer diagnosis, treatment, demographics, and baseline conditions. Results The prevalence of depression at follow-up was 11.4% (95% CI, 10.6%-12.3%), anxiety 7.4% (95% CI, 6.7%-8.2%) and somatization 13.9% (95% CI, 13.0%-14.9%). Vigorous exercise was associated with lower prevalence of depression and somatization. The adjusted prevalence ratio for depression was 0.87 (95% CI, 0.72-1.05) for 3 to 6 MET hours per week(-1), 0.76 (95% CI, 0.62-0.94) for 9 to 12 MET-hours per week(-1), and 0.74 (95% CI, 0.58-0.95) for 15 to 21 MET-hours per week(-1). Compared with 0 MET hours per week(-1), 15 to 21 MET-hours per week(-1) were associated with an adjusted prevalence ratio of 0.79 (95% CI, 0.62-1.00) for somatization. Vigorous exercise also was associated with less impairment in the physical functioning, general health and vitality (P-trend < .001), emotional role limitations (P-trend = .02), and mental health (P-trend = .02) domains as well as higher cognitive function in the domains of task completion, organization, and working memory (P < .05 for all), but not in the domain of cancer pain. Conclusions Vigorous exercise is associated with less psychological burden and cognitive impairment in childhood cancer survivors.