Risk of Jaw Osteonecrosis After Intravenous Bisphosphonates in Cancer Patients and Patients Without Cancer

Objective To compare the risk of jaw osteonecrosis after intravenous (IV) bisphosphonate administered to patients with cancer vs patients without cancer. Patients and Methods We conducted a retrospective cohort study of a 5% national sample of Medicare patients administered IV bisphosphonate from January 1, 2008, through December 31, 2013, for cancer vs noncancer indications. Probable jaw osteonecrosis was estimated with an algorithm including diagnoses, surgical procedures, and imaging studies. A non-IV bisphosphonate comparison group included patients prescribed an oral bisphosphonate for 30 days or less. Results During follow-up, 40 (0.42%) out of 9482 patients with cancer developed probable jaw osteonecrosis compared with 8 (0.05%) out of 16,046 patients without cancer. In a Cox multivariable survival analysis controlling for patient characteristics and number of IV zoledronic infusions, patients without cancer had a hazard ratio of 0.17 (95% CI, 0.06-0.46) for developing jaw osteonecrosis compared with those with cancer. The lower rate of jaw osteonecrosis in patients without cancer was also confirmed in a number of sensitivity analyses. Conclusion The low rate of jaw osteonecrosis in patients with osteoporosis who receive IV bisphosphonate should be weighed against the benefit of those agents in preventing hip and other fractures.