Novel risk factors for osteonecrosis of the jaw in multiple myeloma: A RADAR report.

6623 Background: Osteonecrosis of the jaw (ONJ) was identified in 2001 and is commonly seen in multiple myeloma (MM). The objective of this study is to evaluate novel risk factors in MM cases from a retrospective database. We hypothesized that ONJ may be related to stem cell transplant, chronic kidney disease and active smoking. Methods: We conducted a retrospective case-control study of 231 MM cases (from January 1, 1998 to September 30, 2010) identified from the electronic data warehouse (EDW) at Northwestern University (NU). The EDW is cross-institutional and integrates clinical data across NU. It comprises more than 2.3TB of data on roughly 2 million patients. The search terms used were: bisphosphonates, pamidronate, zoledronic acid, multiple myeloma, plasma cell disorders, osteonecrosis of the jaw, jaw abscess, dental abscess, among other terms described in literature. Data was abstracted onto a standardized form by 2 trained abstractors and validated by a clinician reviewer (BJE). Known and hypothesized new risk factors were abstracted, including duration of myeloma, treatment used, duration of bisphosphonate use, renal function indices, chemotherapy (vincristine, doxorubicin (A), dexamethasone (D) , thalidomide (T), cisplatin (P), cyclophosphamide (C), etoposide (E), novel agents [bevacizumab, sorafenib, angiostatin]) GCSF, smoking, and MM clinical stage. Analyses included T test, Wilcoxon, and log rank analysis. Results: ONJ occurring after MM diagnosis was identified in 33 cases out of a total of 233 cases of MM. ZOL, VAD, DT-PACE, and diabetes were more common in ONJ cases. Log rank analysis identified 2 risk factors for ONJ, the use of DT-PACE (p= 0.003), and complete and partial remission (p=0.007). Stem cell transplant and chronic kidney disease were not associated with ONJ. Conclusions: We identified novel risk factors for ONJ in MM, mainly partial or complete remission and use of DT-PACE. These results should prompt clinicians to heightened awareness and increased surveillance for the symptoms of ONJ for patients treated with DT-PACE.