Nakashima K, Hasegawa D, Tomizawa D, et al. - However, since high survival rates of 80-90% have been reported in recent clinical trials of low-intensity chemotherapy for children with acute myeloid leukemia and Down syndrome (AML-DS), a number of children with AML-DS have complicated comorbidities, including congenital heart disease (CHD), and are therefore unable to enrol in clinical trials, researchers retrospectively evaluated the clinical features and results of AML-DS children excluded from Japanese clinical trials carried out between 2000 and 2015. Twelve children [median age at the diagnosis was 14 months (range, 5 months to 11.5 years)], including hyperleukocytosis complicated with coagulopathy, severe hemophagocytosis, pulmonary fibrosis, and hypoxic-ischemic encephalopathy were identified and were ineligible for CHD and other comorbidities. Data reported that the 5-year overall survival rate was 51%. Investigators found that patients with AML-DS who received insufficient treatment due to severe complication were poor in prognosis. For such cases, the optimal dose intensity of curative chemotherapy should be investigated.