Demographic factors related to young age at diagnosis of chronic myeloid leukemia in India

Background/objectives We have found that chronic myelocytic leukemia (CML) is diagnosed at an earlier age in poorer populations than in more affluent populations. We had used data from the Glivec ® Patient Assistance Program (GIPAP) involving 33,985 patients from 94 participating countries and documented the geographic variation in CML age of onset, with low income identified as a major risk factor for early age of onset. As India is the largest cohort within GIPAP, we studied several demographic factors in this population to investigate other possible contributors to early age at onset. Methods We analyzed data collected 2002-2008 from 14,167 Indian patients to investigate demographic factors related to age at diagnosis focusing on income and occupation as risk factors. Results As in the first study, patients with an earlier age at diagnosis of CML were more likely to be in families with lower annual income. In addition, we found age at diagnosis varied across different occupations; patients who were self-employed and worked in agriculture/fishing were more likely to be diagnosed at a younger age than patients working in the government. Geographic variation in age at CML diagnosis was also observed, possibly reflecting the influence of environmental and socioeconomic factors on the pathogenesis of CML. Conclusions Environmental factors apparently play a major role in determining age of diagnosis of CML. Analytic studies are needed to determine the relative importance of various exposures such as to herbicides/pesticides, dietary habits and other factors related to income to identify specific contributory factors in the pathogenesis of CML.