The Bisphosphonate-Related Osteonecrosis of the Jaw in Patients with Multiple Myeloma: Clinical Value of Serum C-Terminal Telopeptide Levels in Preventive Strategies

Serum CTX in BRONJ Prevention in Multiple Myeloma

Abstract

Objective: Bisphosphonates are standard and effective agents in the treatment of bone disease in multiple myeloma by targeting osteoclast activity and suppressing bone resorption. However, with the increasing use of bisphosphonates, osteonecrosis of the jaw (MRONJ) has been reported more frequently, particularly in patients with multiple myeloma. This serious complication is associated with significant morbidity and lacks a definitive curative treatment. To date, no specific and reliable biomarker has been identified to predict the risk of MRONJ. The present study aimed to evaluate the relationship between serum C-terminal telopeptide (CTX) levels and the development of bisphosphonate-related osteonecrosis of the jaw, as well as the clinical impact of a preventive dental approach in patients with multiple myeloma.

Materials and Methods: In this prospective study, a total of 50 patients with multiple myeloma who were followed in our clinic between February 2009 and February 2010 were evaluated. Twenty-five patients were newly diagnosed and underwent serum CTX measurement and comprehensive dental examination prior to initiation of bisphosphonate therapy. In cases with identified dental risk factors, bisphosphonate treatment was postponed until necessary dental interventions were completed. The study also included 25 previously diagnosed patients who had been receiving bisphosphonate therapy before enrollment. Serum CTX levels were measured using the Elecsys β-CrossLaps assay, and their association with the development of osteonecrosis of the jaw was analyzed.

Results: No cases of osteonecrosis of the jaw were observed in the newly diagnosed group who underwent preventive dental evaluation prior to bisphosphonate therapy. In contrast, the incidence of osteonecrosis of the jaw was 24% in the previously diagnosed group without preventive dental management. Patients who developed MRONJ had significantly lower serum CTX levels compared with those who did not develop osteonecrosis.

Conclusion: There is currently no specific serum biomarker that reliably predicts the risk of bisphosphonate-related osteonecrosis of the jaw in patients with multiple myeloma. Although serum CTX cannot be recommended as a routine screening test, low CTX levels in patients receiving bisphosphonate therapy may serve as a warning biomarker for the development of osteonecrosis of the jaw. Preventive dental examination and appropriate dental management prior to bisphosphonate initiation remain the most effective strategies for reducing MRONJ risk.