Predictors of Outcome In Adult Patients with Acute Myeloid Leukemia In First Relapse,

Abstract 3569

Treatment of patients with acute myeloid leukemia (AML) in first relapse has remained challenging and although relatively high response rates have been reported using selected combination chemotherapy regimens, long term leukemia-free survival has been less than 20% in most studies. A number of predictors of outcome have been reported of which the most significant are duration of first CR (CR1), cytogenetics at diagnosis, age at relapse, and whether allogeneic stem cell transplant (SCT) was performed in CR1 (Breems, DA, JCO, 2005). We sought to examine predictors of outcome after first relapse of AML incorporating some of the more recent relevant covariates such as molecular data, when available. From January 2000 to March 2010, 447 patients with AML (excluding acute promyelocytic leukemia) in first relapse were seen at the University of Texas – MD Anderson Cancer Center (MDACC) and have available survival data; 275 received therapy at MDACC and 66 (24%) achieved a second CR (CR2), with 14 (5%) patients achieving CR without platelet recovery (CRp2). For the overall population, the median survival from relapse is 5 months (range, 1 to 103+) and the median follow-up in surviving patients is 34.3 months (range, 5 to 103+). On univariate analysis, the following factors predicted survival in first relapse: the duration of CR1 (p<0.001), unfavorable cytogenetics at diagnosis (p<0.001) and having NPM1+/FLT3- status at diagnosis (p=0.001), as well as the following variables at relapse: age (p< 0.001), WBC (p<0.001), platelets (p=0.005), peripheral blood blast % (p<0.001), bone marrow blast % (p<0.001), performance status (p<0.001), creatinine (p<0.001), LDH (p<0.001) and albumin (p<0.001). Having FLT3-ITD at diagnosis and undergoing allogeneic stem cell transplant in CR1 were of borderline significance (p value for both =0.08). On multivariate analysis, taking into account only variables with a p<0.1, duration of CR1, age at relapse, unfavorable cytogenetics at diagnosis, and LDH as well as bone marrow blast % at relapse were significant (p<0.001). Positive FLT3-ITD at diagnosis was also significant (p=0.04). When multivariate analysis was conducted in the subset of 121 patients with complete FLT3 and NPM1 mutational status at diagnosis, neither the NPM1+/FLT3- status, nor having FLT3-ITD at diagnosis remained significant. In conclusion, we confirm that the most important predictors for survival in first relapse are duration of CR1, age at relapse, unfavorable cytogenetics, and possibly FLT3-ITD at diagnosis, as well as percentage of bone marrow blasts and LDH at relapse.