The impact of CHOP versus bendamustine on bone mineral density in patients with indolent lymphoma enrolled in the GALLIUM study.

Standard CHOP treatment includes a high cumulative dose of prednisone, and studies have shown increased fracture risk following CHOP. It is unclear whether reductions in bone mineral density (BMD) are caused by glucocorticoids or by the combination with chemotherapy. Our objective was to determine the effect of obinutuzumab (G)/rituximab (R)-bendamustine versus G/R-CHOP on BMD in follicular lymphoma patients. Patients in this GALLIUM post hoc study were ≥60 years old and in complete remission at induction treatment completion (ITC), following treatment with G or R in combination with bendamustine or CHOP. To assess BMD, Hounsfield units (HU) were measured in lumbar vertebra L1 on annual computed tomography. Furthermore, vertebral compression fractures were recorded. Of 173 patients included, 59 (34%) received CHOP and 114 (66%) received bendamustine. At baseline, there was no difference in HU between groups. The mean HU decrease from baseline to ITC was 27.8 after CHOP and 17.3 after bendamustine, corresponding to a difference of 10.4 (95% CI: 3.2-17.6). Vertebral fractures were recorded in 5/59 patients receiving CHOP and in 2/114 receiving bendamustine. CHOP was associated with a significant greater decrease in BMD and more frequent fractures. These results suggest that prophylaxis against BMD loss should be considered.