Bisphosphonate related osteonecrosis of the jaw (BONJ) in cancer patients

Objective: To characterize features and incidence of BONJ.

Methods: A retrospective review of patient's medical and dental charts at the University of Florida (UF) and the associated Veterans Administration Medical Center (VAMC) between 01/04-02/07.

Results: A total of 27 patients were identified with BONJ, median age of 62 y, 19 with myeloma, 3 with prostate cancer, 2 with breast cancer, 2 with head and neck cancers, and one with renal cell carcinoma. There were 21 males. Twelve patients received sequential Aredia and Zometa treatments, eleven had Zometa and 3 had Aredia. Fourteen patients had modest increases in their creatinine. The average number of prior chemo/radiotherapy regimens was 3.5. Nine patients had Thalidomide, 5 had Bortizomib. Primary disease status was as follows: 12 patients in clinical remission, 5 with stable disease and 10 with progressive disease. Eight patients received statin therapy and 6 had diabetes mellitus. The median length of treatment with bisphosphonate before the diagnosis of BONJ was 29 months. BONJ involved the mandible in 21 patients, maxilla in 4 and both in 2 patients. The most frequent presentation was pain, swelling and exposed bone. Ten patients had history of prior dental procedure. The BONJ incidence differed among the 3 different centers where these patients were treated. In the outpatient bone marrow transplant clinic where all patients had myeloma, the total incidence was 13%; while it was 4% for Aredia only. The incidence in the VAMC was 4.2 % while the incidence in the Cancer Center clinic at UF was 1.7 %. In the latter two groups, patients had mostly solid tumors.

Conclusions: Our study supports the increased incidence of BONJ with increased length of therapy. Myeloma patients are more likely than solid tumor patients to develop the complication. Further research to predict individual risk is needed.