Ye X, et al. - In this retrospective analysis, researchers used the Surveillance, Epidemiology, and End Results (SEER) database and examined all patients with new myelodysplastic syndrome (MDS) onset from 2001 to 2013, to investigate the incidence, risk factors, and relative survival of acute myeloid leukemia (AML) secondary to MDS. Overall 36,558 patients with primary MDS were found. Among patients 40 years or younger and among those older than 40, the observed rate of secondary AML (sAML) was 3.7% and 2.5%, respectively. Despite longer survival in younger patients, these patients showed a more negative influence of sAML development on survival. For older but not younger patients, a decreased risk of sAML was reported in correlation with female sex, age, and WHO type MDS with single lineage dysplasia (MDS-SLD). Favorable prognostic factors for survival among older patients with MDS were a married status, black race, female sex, shorter time to sAML, and WHO type MDS-SLD or MDS with ringed sideroblasts. Overall, a lower rate of sAML among MDS patients was reported in the SEER database vs previous reports but, still, worse survival was reported in these patients. The inclusion of clinical and demographic factors in risk evaluation was recommended.