Osteonecrosis of the jaw and survival of patients with cancer: a nationwide cohort study in Denmark

Osteonecrosis of the jaw (ONJ) is an adverse effect of bone-targeted therapies, which are used to prevent symptomatic skeletal events following bone malignancy. We examined the association between ONJ and survival among cancer patients treated with bone-targeted agents. Using nationwide registries and databases in Denmark, we identified 184 cancer patients with incident ONJ between 2010 and 2015, and a comparison cohort of 1067 cancer patients without ONJ and with a history of hospital-administered treatment with bisphosphonates or denosumab initiating from cancer diagnosis. At the date of confirmed ONJ diagnosis, the comparison cohort was matched to the ONJ patients on age, cancer site, year of cancer diagnosis, and stage at diagnosis. The patients were followed up for survival until emigration or 15 June 2016. We computed overall survival and estimated mortality rate ratios adjusted for sex, and for the presence of distant metastases and other comorbidity at start of follow-up. A match was found for 149 of the 184 ONJ patients. The 1- and 3-year survival among all 184 cancer patients with ONJ was 70% (95% confidence interval [CI]: 63%-76%) and 42% (95% CI: 34%-51%), respectively. Among the matched patients, ONJ was associated with an adjusted mortality rate ratio of 1.31 (95% CI: 1.01-1.71). ONJ was associated with reduced survival among cancer patients treated with bone-targeted agents. ONJ may be a marker of advanced disease or of survival-related lifestyle characteristics.