Jaw necrosis risk in cancer patients on zoledronic acid varies with dosing, oral health

Reuters Health - 24/12/2020 - In patients treated with zoledronic acid for bone metastases, the risk of osteonecrosis of the jaw (ONJ) was associated with cancer type, oral health and dosing frequency, researchers found in a recent study.

Overall, almost 3% of such patients will developed ONJ within three years of treatment, they report in JAMA Oncology.

When the study was initiated, "the incidence of ONJ and the risk factors for developing the condition were ill defined," Dr. Catherine Van Poznak of the University of Michigan Medical Center, in Ann Arbor, told Reuters Health by email.

Based on the results, "the risk of ONJ appears to increase over time with use of zoledronic acid," she said. "Categories of patients at higher risk include those with multiple myeloma, those with pre-existing poor-dental-health history, and those who have zoledronic acid dosed more frequently than every five weeks."

The findings "will aid clinicians when counseling patients on their risk of ONJ, and may impact on clinical decisions when choosing dosing intervals of zoledronic acid," she added

Dr. Van Poznak and her colleagues studied nearly 3,500 patients (median age, 63; 52% women) with limited or no previous exposure to bone-modifying agents who were receiving zoledronic acid for metastatic bone disease.

The most common cancers were breast (32%), prostate (20%), lung (19%) and myeloma (17%); 12% had other neoplasms,

Ninety patients developed ONJ, for a cumulative incidence of 0.8% at one year, 2.0% at two years and 2.8% at three years. The three-year cumulative incidence was highest in patients with myeloma (4.3%).

Patients with dosing intervals of less than five weeks were significantly more likely to develop ONJ than were those with less-frequent dosing (hazard ratio, 4.65).

Significantly higher rates of ONJ were also seen in patients with fewer teeth or dentures and in currentgas smoking.

Dr. Evan Rosen, chief of Dental Oncology and Maxillofacial Prosthetics at Miami Cancer Institute, said that in cancer patients, "Dental surgery - including, but not limited to, dental extractions, dental implants, periodontal surgery, and 'deep cleanings' - are known risk factors for development of ONJ following treatment with zoledronic acid, as well as other antiresorptive and antiangiogenic medications."

"Patients with poor oral health, pre-existing dental disease, and chronic oral problems, including ill-fitting intraoral prosthetics, are at higher risk for oral complications post-treatment," he told Reuters Health by email. "As a result, it is important for patients to undergo pre-treatment evaluation so any emergent dental intervention can be completed prior to drug administration. Post-treatment follow-up for maintenance of the dentition by an oral-health professional is also an important component of long-term mitigation of risk for development of ONJ."

"In light of these known risks, multidisciplinary collaboration is recommended between the medical-oncology and dental-oncology teams to coordinate care for this patient population," he concluded.

SOURCE: https://bit.ly/37MAHeZ JAMA Oncology, online December 11, 2020.

By Marilynn Larkin

 



Posted on 24 December 20205 January 2021