Impact of admission body weight and chemotherapy dose adjustment on the outcome of autologous bone marrow transplantation

We performed a retrospective analysis of 473 consecutive adult patients undergoing autologous bone marrow transplantation for hematologic malignancies between 1988 and 1995. The analysis examined whether significant deviation from ideal body mass index is associated with a decrease in event-free survival (EFS), an increase in nonrelapse mortality (NRM) including late toxicities and second malignancies, or relapse. Chemotherapy dosing in underweight and overweight patients is administered based on the relationship of admission body weight (ABW) to ideal body weight (IBW). Doses were adjusted for obesity; however, the adjustment did not obviate increased risk for NRM. Patients were categorized into five groups according to the relationship of ABW to age-adjusted body mass index (aBMI) as a percent of actual BMI, as follows: group I, 70-79%; group II, 80-99%; group III, 100-119%; group IV, 120-139%; and group V, 140-199% aBMI. When body weight was expressed as percent BMI adjusted for age, there was a significantly increased risk for NRM in groups I and IV (p = 0.03 and 0.02, respectively). A trend toward greater NRM in group V (p = 0.10) was also noted. Multivariate analysis confirmed that the risk of NRM for extremely underweight and overweight patients is almost three times that of patients close to ideal body weight. Age-adjusted BMI was an independent predictive factor for NRM but not associated with increased relapse. We determined that dose adjustment could be safely used without significant increase of relapse. In patients with significant deviation of BMI from aBMI, dose adjustment and possible weight normalization should be considered.