Outcomes and genetic dynamics of acute myeloid leukemia at first relapse

Patients with relapsed acute myeloid leukemia (AML) experience dismal outcomes. We performed a comprehensive analysis of patients with relapsed AML to determine the genetic dynamics and factors predicting survival. We analyzed 875 patients with newly diagnosed AML who received intensive treatment or low-intensity treatment. Of these patients, 197 subsequently relapsed. Data were available for 164 of these patients, with a median time from complete remission/complete remission with incomplete blood count recovery to relapse of 6.5 months. Thirty-five of the 164 patients (21%) experienced relapse after allogeneic hematopoietic stem cell transplantation. At relapse, mutations in genes involved in pathway signaling tended to disappear, whereas clonal hematopoiesis-related mutations or TP53 tended to persist. Patients with normal karyotypes tended to acquire cytogenetic abnormalities at relapse. Patients treated intensively had a higher rate of emergence of TP53 mutations (16%), compared to patients given low-intensity treatment (1%, P=0.009). The overall response rates were 38% and 35% for patients treated with salvage intensive treatment or low-intensity treatment, respectively. Seventeen patients (10%) underwent allogeneic stem cell transplantation after salvage therapy. The median overall survival duration after relapse was 5.3 months, with a 1-year overall survival rate of 17.6%. Complex karyotype (hazard ratio [HR]=2.14, P<0.001), a KMT2A rearrangement (HR=3.52, P=0.011), time in remission <12 months (HR=1.71, P=0.011), and an elevated white blood cell count at relapse (HR=2.38, P=0.005) were independent risk factors for overall survival duration. More effective frontline and maintenance therapies are warranted to prevent relapsed AML.