Substance use and survival after treatment for chronic myelogenous leukemia (CML) or myelodysplastic syndrome (MDS).

BACKGROUND: Patients' substance use problems are a particularly understudied aspect of psychosocial variables in cancer treatment. OBJECTIVES: The specific hypothesis tested was that lifetime substance use disorders increased the risk of adverse outcome, in the context of other psychosocial and clinical characteristics demonstrated in other studies to have an impact on treatment outcome. METHOD: Prospective cohort study of 106 adults with chronic myelogenous leukemia or primary myelodysplastic syndrome. None satisfied criteria for current substance abuse or dependence, but the lifetime rates of substance use disorders in this sample were 28% for alcohol, 12% for cannabis, and 9% for cocaine. RESULTS: Participants received treatment as directed by their physicians, and were followed until death or the end of the study (median 1.5 years). Twenty-eight died. Multivariate survival analysis identified three predictors of outcome: lifetime cocaine use, associated with a six-fold increased risk of death (p = .04), and two protective variables, baseline hemoglobin (p = .002) and estimated intelligence quotient (IQ) (p = .04). CONCLUSION: The results of this study highlight the potential significance of substance use disorders, and lifetime cocaine diagnoses in particular, on treatment outcome for people with chronic myelogenous leukemia or myelodysplastic syndrome. Whereas neither lifetime alcohol nor cannabis use were associated with survival on either the univariate or multivariate models of survival, lifetime cocaine diagnoses were associated with significant six-fold increased risk of death (p = .04).