Cancer patients who received IV bisphosphonates had substantially increased risk for jaw osteonecrosis.
Osteonecrosis of the jaw has been reported increasingly in patients who receive IV bisphosphonates (i.e., zoledronic acid and pamidronate) to treat and prevent cancer-related bone lesions. To estimate the incidence of this complication, researchers linked data from the Surveillance, Epidemiology, and End Results (SEER) program (a cancer registry covering one quarter of the U.S. population) with Medicare claims.
About 14,000 cancer patients who received IV bisphosphonates were matched (by variables including age, cancer type, and geographic location) with about 29,000 cancer patients who did not receive bisphosphonates. Because a specific diagnosis code for jaw osteonecrosis did not exist, the diagnosis of "inflammatory conditions of the jaw" and surgery on facial bones were used to signal jaw osteonecrosis. The estimated 6-year risk for either of these outcomes was strikingly and significantly higher among IV bisphosphonate recipients than among nonusers (5.5 vs. 0.3 events per 100 people). The risk for each of these outcomes increased as the cumulative dose of bisphosphonate increased.
Comment: Although this study has several limitations, including no specific diagnosis code for jaw osteonecrosis, the results suggest that patients who receive IV bisphosphonates have a substantially increased risk for jaw osteonecrosis. For primary care physicians, a related and controversial issue is whether long-term use of oral bisphosphonates for osteoporosis also increases risk for jaw pathology. So far, only a handful of cases have been reported with oral drug use, but underreporting is possible. A succinct review of this topic was published in the November 30, 2006, issue of the New England Journal of Medicine (355; 2278-81).
Published in Journal Watch General Medicine July 19, 2007
Wilkinson GS et al. Intravenous bisphosphonate therapy and inflammatory conditions or surgery of the jaw: A population-based analysis. J Natl Cancer Inst 2007 Jul 4; 99:1016-24.