OBJECTIVES:In Brazil, imatinib mesylate is supplied as the first-line therapy for chronic myeloid leukemia in the chronic phase through the public universal healthcare program, Sistema Único de Saúde (SUS). We studied the socio-demographic factors that influenced therapy success in a population in the northeast region of Brazil.METHODS:Patients with chronic myeloid leukemia from the state of Piauí were treated in only one reference center. Diagnosis was based on WHO 2008 criteria. Risk was assessed by Sokal, Hasford and EUTOS scores. Patients received 400 mg imatinib daily. We studied the influence of the following factors on the achievement of complete cytogenetic response within one year of treatment: age, clinical risk category, time interval between diagnosis and the start of imatinib treatment, geographic distance from the patient's home to the hospital, years of formal education and monthly income.RESULTS:Among 103 patients studied, the median age was 42 years; 65% of the patients had 2-9 years of formal education, and the median monthly income was approximately 100 US$. Imatinib was started in the first year after diagnosis (early chronic phase) in 69 patients. After 12 months of treatment, 68 patients had a complete cytogenetic response. The Hasford score, delay to start imatinib and years of formal education influenced the attainment of a complete cytogenetic response, whereas income and the distance from the home to the healthcare facility did not.CONCLUSION:Patients require additional healthcare information to better understand the importance of long-term oral anticancer treatment and to improve their compliance with the treatment.