Background: Guidelines recommend bone-modifying agents (BMAs) for all patients initiating treatment for myeloma. We examined adherence to this recommendation, and BMA effectiveness in the era of bortezomib/lenalidomide-based therapy among Medicare beneficiaries.
Methods: From the linked Surveillance, Epidemiology, and End Results-Medicare registry, we selected beneficiaries receiving anti-myeloma chemotherapy in 2007-2013. We matched BMA recipients (within 90 days of first chemotherapy) to nonrecipients using a propensity score, balancing patient-, disease-, and therapy-related confounders. Cumulative incidence of skeletal-related events (SREs) and overall survival (OS) was compared in proportional hazard models accounting for competing risks and immortal-time bias.
Results: Among 4611 patients with median age of 76 years, 51% received BMA. Bone-modifying agents use remained steady over time (P = .87) and was significantly less frequent for patients who were older, with comorbidities, without prior SRE, and those treated without bortezomib or lenalidomide. In a propensity score-matched cohort, BMA recipients experienced a lower incidence of SRE (11.0% vs 14.6% at 3 years; subhazard ratio, 0.73; 95% CI, 0.60-0.89) and better OS (53.3% vs 47.8% at 3 years; hazard ratio, 0.86; 95% CI, 0.77-0.95). The results were consistent in the subgroup (76%) treated with bortezomib and/or immunomodulatory drugs (IMiDs). The incidence of osteonecrosis of the jaw (ONJ) was 3.2% at 3 years.
Conclusions: In this observational study, the observed benefits of early BMA administration among patients treated with contemporary anti-myeloma regimens were similar to historical clinical trials. Frequent omission of BMA highlights a remediable deficiency in the quality of supportive care, and suggests that timely administration may be a useful indicator of quality care in myeloma.
Keywords: SEER-Medicare; bisphosphonates; bone-modifying agents; health services research; multiple myeloma; supportive care; zoledronate.
© 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.