The Dental Oncology Complication that Wouldn’t go Away

Abstract

Background: Bone modifying agents are used throughout cancer care and their utilisation can optimise advanced stage cancer cases with bone metastases, by reducing skeletal-related events, treatment-induced bone loss and treatment hypercalcaemia. They are also used in patients with a curative intent such as early breast cancer, reducing recurrence and increasing survival rates. Medication-related osteonecrosis of the jaw (MRONJ) is a potential complication following bone modifying agents (BMAs). It represents exposed bone in the maxillofacial region which significantly compromises the quality of life for these patients. Dental disease is the most common initiating factor of MRONJ. We report a case in which MRONJ has dominated cancer care despite its successful treatment. Case presentation: A 69-year-old female was diagnosed with a breast cancer (grade 1, infiltrating ductal carcinoma, pT1c pN1mi(sc) Mx), for which she was treated with a wide local excision and axillary lymph-node clearance. Seven years after initial presentation, the patient presented with metastatic disease involving the left supraclavicular fossa, bone, peritoneum, and liver. Her BMA regime included zoledronic acid intravenous (IV) every month for 12 months and switched to oral zoledronic acid for a subsequent year due to poor venous access. Two years after her diagnosis of metastatic disease, the patient presented with exposed bone in her anterior maxilla, which represented advanced stage MRONJ (AAOMS 3). The exposed bone in the maxilla was treated surgically by sequestrectomy and fistula closure. Three years later (12 years after initial breast cancer diagnosis), the patient was re-admitted with a cervical fascial space infection involving the right mandible. The patient developed another site of advanced- stage MRONJ (AAOMS 3) in the right mandible associated with an orocutaneous fistula. The patient had a marginal resection of her mandible, fistula closure and extraction of the remaining teeth under general anesthetic. Conclusion: The practicing oncologist needs to be cognisant of the possibility of MRONJ in both the curative and palliative setting. Traditionally, oncology care has required a significant degree of self-reliance on patients to navigate dental treatment pathways. Integration of dental clinics into oncology pathways would help eliminate this need for self-reliance. MRONJ is an inevitable risk for a large cohort of oncology patients and active engagement of dental-oncology specialities will ensure optimal care for patients.