Osteonecrosis of jaw beyond antiresorptive (bone-targeted) agents: new horizons in oncology

Oral mucosal changes induced by anticancer targeted therapies and immune checkpoint inhibitors

Development of biological targeted therapies and immune checkpoint inhibitors has redefined the treatment for many cancers; however, the increasing use of new protocols has led to physicians observing a new spectrum of toxicities. To date, oral adverse events induced by these new anticancer therapies have been mainly reported using nonspecific terminology ("stomatitis," "mucosal inflammation," "mucositis") and remain poorly characterized, with the exception of mammalian target of rapamycin (mTOR) inhibitor-associated stomatitis. Oral toxicities of targeted therapies often display very characteristic features which clearly differ from classic oral injuries observed with cytotoxic chemotherapy and/or radiotherapy. In addition, they frequently affect more than 20% of treated patients and can lead to a significant morbidity or permanent treatment discontinuation. Oral mucosal toxicities described in this review include mTOR inhibitor-associated stomatitis (mIAS); stomatitis, benign migratory glossitis, and osteonecrosis of the jaw associated with multi-targeted kinase inhibitors of the VEGF and PDGF receptors; mucositis induced by EGFR inhibitors (in monotherapy or in combination with head and neck radiotherapy and/or chemotherapy); hyperkeratotic lesions with BRAF inhibitors; pigmentary changes and lichenoid reactions secondary to imatinib; and more recent data on the "Osler-Weber-Rendu-like syndrome" described with the antibody-drug conjugate, TDM-1. Finally, we provide, to our knowledge, the first available structured data on oral toxicities induced by the new recently FDA- and EMA-approved monoclonal antibodies targeting PD-1. Clinical management of these targeted therapy-related oral changes is also discussed.

Adjudication of osteonecrosis of the jaw in phase III randomized controlled trials of denosumab: a systematic review

PURPOSE

Denosumab (an anti RANKL antibody) is known to be associated with an increased risk for osteonecrosis of the jaw (ONJ). Due to the variety of clinical presentation, many ONJ definitions are used. Evaluation of ONJ's frequency during phase III randomized controlled trials (RCTs) is crucial to assess benefit-risk ratio. We verified that phase III RCTs involving denosumab reported the definition of ONJ used.

METHODS

We systematically searched in Central, Medline, Cochrane, and Scopus, until 31 August 2015. We included original phase III RCTs, involving denosumab. Post hoc analysis and trial extension were excluded. Articles that did not mention ONJ in their methods or results were excluded. The primary outcome was the prevalence of a complete definition of ONJ. When no definition was provided, ONJ adjudication process was analyzed.

RESULTS

Of 313 articles found, 13 RCTs were included. A definition of ONJ was detailed in two RCTs (15%). For the remaining 11 RCTs, adjudication process was mentioned for nine. In those processes, "blinded," "expert," and "independent" were the most used words.

CONCLUSION

Most of the published phase III RCTs involving denosumab did not specify the definition of ONJ used to adjudicate events in the study. Instead of definition, non-scientific and non-reproducible expressions were used. Because the chosen definition could impact the ONJ estimated frequency, it should be mandatory to give the precise definition used in each RCT publication involving denosumab.

Osteonecrosis of the Jaws in Patient Received Bisphosphonates and Sunitinib Separately: A Case Report

Recently published reports have suggested that antiangiogenic drugs such as sunitinib could potentiate the osteonecrosis of the jaw (ONJ) induced by bisphosphonates (BPs) and even induce this adverse effect per se. We reported a case of ONJ with renal cell carcinoma under sunitinib medication and history of BPs therapy. A 53-year-old man was referred to the oral surgery clinic complaining of painful exposed oral lesion and bone extraction from right lower jaw in the mouth. He underwent nephrectomy followed by 5 months treatment with cycles of 50 mg sunitinib (Sutent^®) once a day for 4 weeks followed by 2 weeks drug free before lesion exposure in October 2016. However, the patient has encounter to intermittent mucositis and gingivitis in oral cavity several times. Our patient had a history of zoledronic acid (4 mg intravenously two times) administration due to primary cancer misdiagnosis. In our case, no dental procedure contributed to the occurrence of ONJ. The lesion was improved by sunitinib cessation and administration of antibiotics through 2 weeks. Mucosal injury induction as well as inhibition of angiogenic signaling pathways by sunitinib administration may have precipitated the occurrence of ONJ. In addition, a possible synergistic effect by previously BP treatment is another accused.

Osteonecrosis of the Jaws (ONJ) after Bisphosphonate Treatment in Patients with Multiple Myeloma: Decreasing ONJ Incidence after Adoption of Preventive Measures

Bisphosphonates (BPs) are administered to Multiple Myeloma (MM) patients with bone lytic lesion. Osteonecrosis of the Jaw (ONJ) is a complication reported since 2003 in patients treated with intravenous (IV) BPs such as zoledronic acid and pamidronate, with 6%–26.3% frequency in early literature series, before some preventive measures were recommended. We evaluated the occurrence of ONJ with and without dental preventive measures in MM patients treated with BPs in our centre between 1996 and 2015. Since 2005, MM patients (already under treatment or before treatment) underwent a baseline mouth assessment (dental visit, Rx orthopantomography, and eventual tooth avulsion or dental care if necessary) and were followed by a multidisciplinary team. We reviewed the charts of 119 MM patients receiving IV BPs, classified into 3 groups: (a) “historic group” (21 patients who had started BP treatment in years before the awareness of ONJ); (b) “screening group” (20 patients starting BPs without baseline evaluation); and (c) “prevention group” (78 patients starting therapy only after baseline preventive assessment and eventual dental care measures). ONJ was observed in 3/21 patients (14.2%) from group a, in 2/20 patients (10%) from group b, and in no patients from group c (0%). Notably, the median number of IV BP administrations decreased after 2005. Our data confirmed a meaningful reduction of ONJ risk in MM patients treated with BPs if preventive measures are applied. Both implementation of prevention measures and reduction of cumulative doses of IV BPs could have contributed to a decreased incidence of ONJ.

Delayed Diagnosis of Osteonecrosis of the Jaw (ONJ) Associated with Bevacizumab Therapy in Colorectal Cancer Patients: Report of Two Cases

Medication-induced Osteonecrosis of the Jaw (MRONJ) has been reported not only after use of antiresorptive agents (bisphosphonates and denosumab), but also in cancer patients receiving antiangiogenic agents, alone or combined with antiresorptive drugs. We report two cases of MRONJ observed in colorectal cancer patients after bevacizumab therapy only. MRONJ was diagnosed, respectively, two and seven months after a tooth extraction; both the patients had received two courses of bevacizumab infusions (for a total of 29 and 10 administrations, respectively). We discuss if tooth extraction during or after antiangiogenic therapy could be a potential trigger of MRONJ, but also if an underlying bone disease not evident before oral surgery might be a possible cause. A careful drug history has to be registered by dental specialists in cancer patients before oral surgery and adequate imaging might be obtained to avoid a delayed diagnosis.