Neurocognitive impairment and substance use in adult survivors of childhood cancer: a cross-sectional analysis from the Childhood Cancer Survivor Study

Background: Adult survivors of childhood cancer are at risk for neurocognitive impairment, emotional distress, and chronic pain, factors independently associated with substance use. However, interrelationships among these factors and their association with substance use remain poorly understood. Methods: Participants from the Childhood Cancer Survivor Study (CCSS) who reported symptoms of neurocognitive problems, distress, pain, and substance use were included. Data for these cross-sectional analyses were drawn from CCSS follow up questionnaires administered between 2003 and 2007. Polytomous regressions examined associations between neurocognitive impairment and substance use (alcohol: occasional, risky, heavy; smoking: current) and whether these associations were moderated by psychosomatic symptoms. The CCSS cohort study is registered with ClinicalTrials.gov, NCT01120353. Findings: 11,151 participants were included (53.2% female; mean age 31.4 years, SD 7.5). Survivors reported risky (40.9%; n = 4059/9894), or heavy (11%; n = 1096/9894) alcohol use and more than 25% reported previous (14.6%; n = 1482/10,182) or current (13.7%; n = 1395/10,182) cigarette use. Impaired emotional regulation was associated with smoking (odds ratio 1.81, 95% CI 1.53-2.14) and risky drinking (1.59, 1.25-2.03). Impaired emotion regulation with somatisation was associated with decreased occasional (0.54, 0.0-0.95) and heavy drinking (0.54, 0.0-0.95). Organisation impairment with somatisation was associated with decreased heavy drinking (0.34, 0.15-0.73), whereas pain with organisation impairment was associated with increased occasional (1.81, 1.03-3.19) and risky drinking (2.18, 1.24-3.85). Memory impairment was associated with risky (1.38, 1.10-1.73) and occasional drinking (1.37, 1.09-1.71). Interpretation: Neurocognitive impairment was associated with substance use and modified by psychosomatic symptoms. Findings support integrated screening to inform targeted interventions. Funding: National Cancer Institute, Princess Margaret Cancer Centre Foundation, Ontario Ministry of Health and Long-Term Care, National Cancer Institute Cancer Center, and American Lebanese Syrian Associated Charities.