Osteonecrosis of the jaw (ONJ) in renal cell cancer patients after treatment including zoledronic acid or denosumab.

Osteonecrosis of the jaw (ONJ) associated with the use of bisphosphonates has been rarely reported in metastatic renal cell cancer (RCC) patients. Since the introduction of combined therapies consisting of nitrogen-containing bisphosphonates (NBPs) and targeted agents, an increasing number of RCC patients were reported to develop ONJ, suggesting that therapeutic angiogenesis suppression might increase the risk of ONJ in NBPs users. We performed a multicenter retrospective study and reviewed literature data to assess the occurrence and to investigate the nature of ONJ in RCC patients taking NBPs and targeted agents. Nine Italian Centers contributed to the data collection. Patients with exposed and nonexposed ONJ were eligible for the study if they had been taking NBPs and were receiving targeted agents at the time of ONJ diagnosis. Forty-four RCC patients were studied. Patients were mostly male (82%), with a median age of 63 years (range, 45-85 years). Zoledronic acid (93%) and sunitinib (80%) were the most frequently used NBP and antiangiogenic agent, respectively. Other agents included Pamidronate, ibandronate, sorafenib, bevacizumab, mammalian target of rapamycin inhibitors. Forty-nine sites of ONJ were encountered, with the mandible being the preferred site of ONJ (52%); both jaws were affected in 5 cases (12%). The most common precipitating event was dental/periodontal infection (34%), followed by tooth extraction (30%). Oral triggers of ONJ were missing in 10 cases (23%). This unexpectedly high number of ONJ cases, in comparison with literature data, suggests that frequency of ONJ in RCC patients might be largely underestimated and suggests a potential role for targeted agents in the incremental risk of ONJ.