Marijuana/tobacco use and patient-reported outcomes (PROs) in adult survivors of childhood cancer.

Abstract

175 Background: In 2017, the National Academy of Medicine reported adverse physical and psychosocial outcomes associated with marijuana use, and an increased risk of marijuana use among those who use tobacco. However, the association of marijuana and/or tobacco use with PROs has not been well-studied in survivors of childhood cancer. Methods: A random sample (stratified on self-reported smoking status) of 287 adult survivors of childhood cancer was selected from the St. Jude Lifetime Cohort Study. Chemotherapy and radiotherapy were abstracted from medical records. Marijuana use was self-reported and classified as past/current vs. never use. Current tobacco use was determined using serum cotinine concentrations by liquid chromatography tandem mass spectrometry. PROs were evaluated by physical and mental component summary (PCS and MCS) scores from the Medical Outcomes Study SF-36. Linear regression was used to evaluate associations of marijuana and tobacco use with PROs after adjusting for covariates, and the results were stratified by treatment modality. Results: Survivors’ mean age at study participation was 33.6 years (SD = 9.1), mean years from diagnosis was 24.2 (SD = 6.2). 61.3% used marijuana and 39.4% were current tobacco users. 79.3% of the tobacco users had marijuana use. Marijuana and tobacco were independently associated with lower PCS (βs = -3.1 and -2.9, respectively, p’s < 0.05) and MCS (βs = -3.3 and -3.2, respectively, p’s < 0.01). Among survivors who received chemotherapy, marijuana and tobacco were associated with lower PCS (β = -4.3, p < 0.01; β = -2.8, p < 0.05, respectively) and MCS (βs = -4.8 and -3.1, respectively, p’s < 0.05). In survivors who received radiotherapy, marijuana, but not tobacco, use was associated with lower PCS (β = -3.6, p < 0.05) and MCS (β = -4.6, p < 0.05). Among those who received neither chemotherapy nor radiotherapy, each substance was independently associated, but not significantly, with lower PCS and MCS. Conclusions: Among adult survivors of childhood cancer, marijuana users likely co-used tobacco, and both substances were independently associated with lower PROs. When associations with treatment exposures were assessed, different profiles of PRO scores were identified.