Risk Factors of Myelodysplastic Syndromes (MDS): A Case-Control Study.

Little is known about the etiology of MDS. A hospital-based case control study was conducted to investigate the association between lifestyle characteristics and MDS risk. Cases included 354 newly diagnosed adult de novo MDS cases registered at M. D. Anderson Cancer Center (MDACC) between 1996 and 2003. Four hundred and fifty two age-, sex- and race-matched healthy controls were recruited among visitors to MDACC who accompanied patients to different clinics excluding the Leukemia clinic. A validated questionnaire was used to collect demographic and epidemiological information including lifetime history of smoking, alcohol drinking and occupational history. Multivariate logistic regression analysis adjusting for all variables simultaneously was used. The distribution by FAB type was 102 (29%) RA/RARS, 43 (12%) CMML and 209 (59%) RAEB/RAEB-T. The mean age of patients was 64 years (range: 24 to 89), the male to female ratio was 2.72, and 94% of cases were whites. Abnormal cytogenetics was found in 49% of the patients. Multivariate logistic regression analysis was performed among all MDS cases and among each FAB type. For all MDS combined, having a first degree relative diagnosed with a hematopoietic cancer (Odds ratio (OR)=1.92, 95% CI: 1.11–3.33), having ever smoked (OR=1.65, 95% CI: 1.19–2.29), having been exposed to agricultural chemicals (OR=4.57, 95% CI: 1.78–11.7) and solvents (OR=2.08, 95% CI: 1.22–3.54) were associated with MDS risk. Wine drinkers had a reduced risk of MDS as compared to those who never drank alcohol (OR=0.54, 95%: 0.37–0.79). For the RA/RARS type, smoking (OR=2.16, 95% CI: 1.3–3.6) and having been exposed to agricultural chemicals (OR=4.64, 95% CI: 1.27–16.9) were the only two risk factors identified. Wine drinkers were at reduced risk (OR=0.51, 95% CI: 0.29–0.91). For the RAEB/RAEBT type, a positive family history of hematopoietic cancer (OR=2.16, 95% CI: 1.17–3.98), smoking (OR=1.55, 95% CI: 1.05–2.30) and exposure to agricultural chemicals (OR=4.12, 95% CI: 1.51–11.3) or solvents (OR=2.83, 95% CI: 1.59–5.05) were independent risk factors. Also drinking wine seemed to reduce the risk by almost 50% (OR=0.51, 95% CI: 0.32–0.81). We also found a joint effect between smoking and chemical exposures with the largest OR found among smokers who were also exposed to solvents or agricultural chemicals as compared to never smokers without chemical exposures (OR=3.22, 95% CI: 2.11–4.92, Trend test: p<0.0001). Results from this large study suggest that several factors play a role in predisposing to MDS with possible joint effects. Risk profiles seem to differ by FAB type. Further population-based studies are needed to confirm these findings. Supported by NCI grants CA91340 and CA 100632.