LAUSR

We read with great interest the paper by Loyson et al. reporting the ONJ (osteonecrosis of jaw) incidence in cancer patients receiving bone metastases long-term treatment with bone resorption inhibitors (BRIs): bisphosphonates and/or denosumab [1]. The Authors are to be congratulated for their effort to give clinical community some useful data not easily obtainable from randomized trials. The paper data might seem not easily readable and understandable but actually they are an important aid to evaluate pros and cons of prolonged treatment in this setting, in our opinion. Firstly, the work confirms the underestimation of frequency of ONJ figures in recent large clinical trial papers, that reported 1–2% ONJ rates [2], against rates up to 15.5% in this study [1]. Secondly, the increasing ONJ risk after prolonged treatment with BRIs [3–5] is confirmed, with slightly higher risk after denosumab but also with somewhat different time-toonset between denosumab and zoledronic acid treatment. Moreover, in this paper important actuarial estimates (by Kaplan–Meier method) are reported, not available in other papers [2,3,5]. The Authors correctly pointed out the weaknesses of their study (lack of prospective screening for ONJ; lack of data on dental extractions in the control groups; different time point of switching in the sequential group). Nevertheless, some points might be clarified to enlarge the value of their ‘real life’ work for clinicians and patients, in our opinion.