Use of Bisphosphonates in Elderly Patients With Newly Diagnosed Multiple Myeloma.

Background: Bisphosphonates reduce skeletal-related events (SREs) in patients with multiple myeloma (MM) and, in some studies, improved survival. Since 2011, bisphosphonate use has been recommended by NCCN for all patients with newly diagnosed MM receiving antineoplastic therapy independent of the presence of bone disease. This study investigated their use after these guidelines were established.
Methods: We identified patients aged ≥65 years in the SEER-Medicare database with newly diagnosed MM between January 1, 2012, and December 31, 2013, who received antineoplastic therapy, had ≥6 months of follow-up, and did not receive prior bisphosphonates. Presence of SREs at diagnosis was identified, including pathologic fracture, spinal cord compression, radiation to bone, or surgery to bone. Use of bisphosphonates was defined as having ≥1 claim for an intravenous or oral bisphosphonate within 6 months after the start of antineoplastic therapy. We used multivariable modeling to compare users with nonusers, controlling for demographic and clinical covariates. We compared overall survival between users and nonusers using proportional hazards analysis.
Results: Of 1,309 patients identified, 720 (55%) used a bisphosphonate. Factors associated with use included SRE at diagnosis (adjusted odds ratio [AOR], 2.60; 95% CI, 1.98-3.40), hypercalcemia (AOR, 1.74; 95% CI, 1.26-2.41), and use of proteasome inhibitor + immunomodulatory imide therapy (AOR, 1.70; 95% CI, 1.21-2.39). Chronic kidney disease (AOR, 0.48; 95% CI, 0.35-0.66) was associated with decreased use. Bisphosphonate use was associated with reduced mortality (hazard ratio, 0.70; 95% CI, 0.56-0.88). Conclusions: Although bisphosphonate use is recommended for all patients with newly diagnosed MM receiving antineoplastic therapy, 45% of patients in the United States did not receive this guideline-recommended care.