title: Regional variations in age at diagnosis and overall survival among patients with chronic myeloid leukemia from low and middle income countries.
abstract: BACKGROUND
  The epidemiology of chronic myeloid leukemia (CML) in low and middle income countries is limited. As a result, we analyzed a contemporary cohort of patients from low and middle income countries treated with Imatinib through The Glivec(®) International Patient Assistance Program (GIPAP).
  
  
  METHODS
  Generalized estimating equations (GEE) and Kaplan-Meier estimation were utilized to test for regional variations in age at diagnosis and overall survival among 33,985 patients from 94 countries.
  
  
  RESULTS
  Patients participated from Asia (79.2%), Africa (9.4%), Latin America (8.7%) and Southern/Eastern Europe (2.5%). Sixty-one (61.2%) percent were male. Mean age at diagnosis was 38.5 years (9.4% <20 years and only 4.7% ≥65 years). Using GEE, Asians were youngest (38.3 years), followed by Africans (39.5 years), Southern/Eastern Europeans (41.1 years) and Latin Americans (41.3 years; p < 0.0001). Diagnoses were predominately in chronic stage (78.3%). In 2002, 85.2% of patients had a delay in treatment >1 year; decreasing to 15.5% in 2010 (p < 0.0001). The 3-year overall survival probability was 89.4% (95% CI, 88.9-89.9). In multivariate analysis, risk of death increased among patients 65 years or older at diagnosis (p < 0.0001), time from diagnosis to treatment >1-year (p < 0.0001), diagnoses in the accelerated or blast crisis (p < 0.0001), initial dose of Imatinib >400 mg (p < 0.0001) and among Latin Americans and Africans (p < 0.0001).
  
  
  CONCLUSIONS
  The GIPAP cohort is the largest series of patients with CML described from low and middle income countries. Differences in age at diagnosis and overall survival exist within and between regions. Additional epidemiological studies should be conducted to assess for possible environmental factors associated with the earlier age at onset.
authors: The George Washington University School of Public Health and Health Services, Department of Epidemiology and Biostatistics, 2100 West Pennsylvania Avenue, NW, 8th Floor, Washington, DC 20037, USA.
authors: Adam M
authors: AM
authors: Mendizabal
authors: Pat
authors: P
authors: Garcia-Gonzalez
authors: Paul H
authors: PH
authors: Levine
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D019049:Developed Countries / Q000706:statistics & numerical data; D003906:Developing Countries / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis* / Q000191:economics / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors; D055815:Young Adult