Body mass index does not impact hematopoietic progenitor cell mobilization for autologous hematopoietic cell transplantation

Background Obesity has implications for hematopoietic progenitor cell (HPC) mobilization, chemotherapy administration, and medication dosing. We analyzed the impact of obesity on HPC mobilization as well as key outcomes that are associated with cell dose in autologous hematopoietic cell transplantation (AHCT) recipients. Methods We conducted a retrospective cohort study on 556 consecutive eligible AHCT recipients at our institution from 1/2004 to 12/2009. Patients were categorized into four groups based on the body mass index (BMI): underweight (BMI < 18.5), normal (18.5-24.9), overweight (25.0-29.9), or obese (>= 30.0). Primary endpoints of interest included HPC mobilization, neutrophil and platelet recovery, hospital stay and survival. Results The diagnoses were mostly non-Hodgkin lymphoma, multiple myeloma, and Hodgkin lymphoma. The majority of the patients had received three or less prior chemotherapy regimens and had not received prior radiation therapy. Most patients had chemosensitive disease at time of transplant. For HPC mobilization regimen, 68% received chemotherapy and G-CSF, 32% received G-CSF alone. Busuflan/etoposide/cyclophosphamide, melphalan, and busulfan/cyclophosphamide were used for conditioning. Obesity did not correlate with HPC mobilization and had no association with neutrophil or platelet recovery, or length of transplant hospitalization. On multivariable analysis, obese patients demonstrated better survival than those who were not obese. Conclusion Obese AHCT recipients had similar rates of HPC mobilization, neutrophil and platelet engraftment and length of transplant hospitalization, and experienced better survival compared with recipients with lower BMI. High BMI by itself should not be considered as a contraindication to AHCT.