Among 103 patients in the secondary cohort, whose disease had transformed to tAML, 29 went to HCT without further therapy; 74 received induction chemotherapy, of whom 23 responded (tAML resp) whereas 51 proceeded to HCT without having responded to chemotherapy. Among 121 patients in the de novo cohort whose disease had transformed to tAML, 34 underwent HCT without additional therapy; 82 patients received induction chemotherapy, and 37 responded (tAML resp) whereas 50 proceeded to HCT without having shown responses to chemotherapy.

tAML indicates MDS transformed to AML (≥20% myeloblasts); RA, refractory anemia; RARS, RA with ringed sideroblasts; RCMD, refractory cytopenia with multilineage dysplasia; MDS-U, undefined MDS; RAEB-1, RA with excess blasts (5%-9%); RAEB-2, RAEB (10%-20%); CMML, chronic myelomonocytic leukemia (according to WHO); and —, not applicable.

Patients with secondary MDS/tAML were classified according to the FAB⁹  classification (but patients with ≥20% myeloblasts were considered to have tAML) and patients with de novo MDS/tAML according to the WHO classification.¹⁰  However, all patients with at least 20% myeloblasts in the marrow were considered to have tAML (AML with multilineage dysplasia according to WHO).

Classified by IPSS criteria.