Prognostic Impact Of Body Mass Index (BMI) In Acute Myeloid Leukemia (AML)

Obesity is an increasing matter of concern worldwide. A few studies suggested that BMI might be a risk factor for outcome in different malignancies including AML. However, not all studies could confirm the prognostic value of BMI in AML. Also, capping chemotherapy dose calculation at 2m² of Body Surface Area (BSA) is widely used, but there is no strong evidence-based rationale for this. With this background, this single centre report aimed to assess whether BMI and chemotherapy dose capping could be correlated with outcome in AML patients receiving intensive induction and consolidation chemotherapy.

Between 2003 and 2012, all consecutive AML patients referred to our centre were prospectively included in this analysis. Eligible patients were those treated with intensive induction chemotherapy (consisting in cytosine arabinoside and anthracyclines). Acute promyelocytic leukemia cases were excluded. Anthropomorphic, patients, cytogenetic and molecular AML characteristics were collected and analyzed to assess their impact on Overall Survival (OS), Leukemia-Free Survival (LFS) and Complete Remission Rate (CR1). Analyses were performed using the logistic regression method. For every patient, BSA was capped at 2m² for chemotherapy dose calculation.

In all, data were available for 233 patients: median age was 56 (range, 16-80) years; 60% were men; median weight was 69 kg (range, 40-158); median height 169 cm (range, 146-207); BSA > 2m² was observed in 15% of cases; underweight was seen in 7% of cases, while overweight represented 33%, and truly obese patients 10%. 64% had a Performance Status (PS) of 0 or 1.

In terms of AML characteristics, secondary AML was diagnosed in 16% of cases. The good, intermediate, and poor cytogenetic risk groups represented 9%, 67%, and 24%, respectively. FLT3-ITD was observed in 17% of cases; (bi allelic) CEBPα mutation in 6% and NPM1 mutation in 23%.

27% of patients could proceed to allogeneic stem cell transplantation.

With a median follow-up of 40.2 (range, 0.69-107.7) months, CR1 was achieved in 71% of cases. Overall median OS was 51±4 months, and median LFS was 45±4 months. In multivariate analysis including all relevant factors from the univariate analysis, and after adjustment for gender, BMI did not prove to be significantly associated with OS (p=0.98; HR=1.0;95%CI [0.951-1.052]), nor with LFS (p=0.88;HR=1.0;95%CI [0.957-1.05]). Also, obesity was not associated with CR1 achievement (p=0.70;HR=1.3;95%CI [0.360-4.56]). Factors significantly associated with OS were age under 60 years (p<0.0001;HR=2.6;95%CI [1.7-4.1]), good versus intermediate (p<0.026;HR=5.0;95%CI [1.2-20.8]) and good versus poor cytogenetic risk group (p<0.0001;HR13;95%CI [3.2-58.3]), presence of FLT3-ITD (p=0.058;HR=1.6;95%CI [1.0-2.7]), and initial White Blood Cells Count (p=0.008;HR=1.8;95%CI [1.2-2.8]). Finally, outcome of patients with BSA >2 m² (who underwent chemotherapy capping) was not different from other patients: BSA > 2 m² did not impact OS (p=0.65;HR=0.84;95%CI [0.39-1.8]), or LFS (p=0.6;HR=0.82;95%CI [0.38-1.75]), or CR1 (p=0.5;HR=0.63;CI [0.162-2.432]).

BMI doesn’t seem to be a prognostic factor in intensively treated AML patients. Chemotherapy dose calculation capping at 2m² of BSA is not associated with a poorer outcome in this population.

No relevant conflicts of interest to declare.