Osteonecrosis of the Jaw (ONJ) in Patients with Multiple Myeloma, Receiving Bisphosphonate Therapy, Is Independent of Renal Function: Single Institute Experience of an Emerging Clinical Problem.

Introduction: Use of bisphosphonate (zoledronic acid and pamidronate) for prevention of pathological fractures is standard of care in multiple myeloma (MM) patients with osteolytic bone lesions. While clinical trials have investigated effectiveness of these agents for up to 2 years of use, clinical practice has incorporated their use indefinitely. With improvement in survival through availability of novel agents in MM patients, the use of bisphosphonate therapy has also prolonged. Recent reports unveiled a new side effect of Bisphosphonate therapy i.e., ONJ, characterized by necrosis of the jawbone with antecedent subluxation or loss of the teeth and ulceration of the gum mucosa. The underlying etiology remains elusive, and in the absence of effective remedy ONJ has raised significant concerns upon the duration of treatment with Bisphosphonate. We investigated the magnitude of this problem among MM patients receiving Biphosphonate therapy at our institute. Methods: We conducted a retrospective review of all patients diagnosed with MM at our institute since 2001 who received bisphosphonate treatment and developed ONJ. Clinical characteristics, prior treatments and renal function prior to development of ONJ were evaluated. Results: Records of 20 pts who developed ONJ were reviewed. The median age of these pts was 57 (range 45–69). Among these, 9 were males, 11 were females. All pts (100%) had stage III MM. 11 patients (55%) received 2 or more antimyeloma treatment. 14 pts (70%) were on Zoledronic acid, 5 pts (25%) were on Pamidronate, and 1 pt (5%) was first on Zoledronic acid then switched to Pamidronate. Out of those 20 patients, 19 (95%) had normal renal function prior to and after development of ONJ, with Creatinine level range of (0.5–1). Only 1 patient (5%) had decreased renal function prior to development of ONJ, with Creatinine level of 6.6 Conclusion: Although the number of patients reported are small, experience at our center with ONJ in MM patients who were on Bisphosphonate failed to show any association with renal function. Interestingly all patients who developed ONJ were stage III MM. There are currently no established guidelines for prevention or treatment of this disorder.