Substance use behaviors in adolescent and young adult cancer patients: Associations with mental and physical health.

OBJECTIVE: Cancer diagnosis in adolescents and young adults (AYAs) coincides with the developmental initiation of substance use and emergence of affective disturbance. We examined substance use behaviors and risk-stratified associations with mental and physical health, as well as objective indicators of tobacco and cannabis use and concordance with self-report and medical records. METHODS: AYAs were 15 to 39 years at cancer diagnosis and >/=18 years and >/=6 months postdiagnosis at study enrollment. Risk-stratified groups included nonsmoker/nondrinker, nonsmoker/drinker, smoker/drinker. Assessments included demographics, past year tobacco, alcohol, and cannabis use, depression, anxiety, sleep, and physical activity. Urine analysis provided biochemical verification of tobacco and cannabis use. RESULTS: Participants included 100 AYAs (60% male) with primarily hematological cancers (88%). Past year alcohol, tobacco, and cannabis use prevalence rates were 80%, 15%, and 33%, respectively. A minority (non-users) refrained from both alcohol and tobacco (20%), while most were exclusively alcohol users (65%) or alcohol and tobacco co-users (15%). Relative to other sub-groups, co-users reported more depressive and anxious symptoms, while non-users reported more physical activity. More frequent tobacco and cannabis use were associated with more depressive and anxious symptoms, while more frequent alcohol use was associated with lower physical activity. There were no group differences or associations with sleep quality. There was considerable discordance between tobacco use self-report, biochemical verification, and medical record documentation. CONCLUSIONS: Substance use among AYAs is common and detrimental to mental and physical health, especially among more frequent users and co-users, highlighting the need for early assessment and intervention.