Ye X, et al. - In the Surveillance, Epidemiology, and End Results (SEER) database, researchers evaluated the incidence, risk factors, and relative survival of acute myeloid leukemia (AML) secondary to myelodysplastic syndrome (MDS) in this retrospective analysis. Cases with new MDS onset from 2001 to 2013, documented in SEER, were included (n = 36,558). Patients 40 years or younger exhibited a 3.7% rate of secondary AML (sAML), and it was 2.5% among those older than 40. For the younger group, a significantly shorter median transformation interval was reported. For both age groups, significantly longer median overall and cancer-specific survival were observed in those who did not develop sAML. Despite a longer survival of younger patients vs older ones, a more negative influence of sAML development on survival was seen in younger patients. 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. Compared with previous reports, lower rate of sAML in patients with MDS was reported in the SEER database, but a worse survival was still noted in these patients. Incorporating clinical and demographic factors in the risk evaluation was recommended.