This study explores the hypothesis that genetic differences related to an ethnic factor may underlie differences in phenotypic expression of myelodysplastic syndrome (MDS). First, to identify clear ethnic differences, we systematically compared the epidemiology, and the clinical, biological and genetic characteristics of MDS between Asian and Western countries over the last 20 years. Asian MDS cases show a 2- to 4-fold lower incidence and a 10-year younger age of onset compared to the Western cases. A higher proportion of Western MDS patients fall into the very low- and low-risk categories while the intermediate, high and very high-risk groups are more represented in Asian MDS patients according to the Revised International Prognostic Scoring System. Next, we investigated whether differences in prognostic risk scores could find their origin in differential cytogenetic profiles. We found that 5q deletion (del(5q)) aberrations and mutations in TET2, SF3B1, SRSF2 and IDH1/2 are more frequently reported in Western MDS patients while trisomy 8, del(20q), U2AF1 and ETV6 mutations are more frequent in Asian MDS patients. Treatment approaches differ between Western and Asian countries owing to the above discrepancies, but the overall survival rate within each prognostic group is similar for Western and Asian MDS patients. Altogether, our study highlights greater risk MDS in Asians supported by their cytogenetic profile.
Keywords: Asia; ETV6; Europe; IDH1/2; RUNX1; SF3B1; SRSF2; U2AF1; cytogenetics; del(20q), TET2; del(5q), trisomy 8; myelodysplastic syndrome; prognosis; survival; treatments.