Osteonecrosis of the jaw in an anti-resorptive naïve patient taking trastuzumab and pertuzumab: case report.

Breast cancer is the most common cancer affecting women in Australia, and second overall for all Australians. Molecular targets have been developed in the management of breast cancer to allow directed therapy. Complications such as nausea and vomiting can be common as well as less common such as osteonecrosis of the jaw (ONJ). While previously thought to be attributable only to bisphosphonate medications, there has been an increase in recognition of other medications that may also cause this complication. This case report demonstrates a first instance of osteonecrosis of the jaw attributable to pertuzumab and trastuzumab, indicated in the management of HER2 positive metastatic breast cancer, in a patient naïve to ONJ associated anti-resorptive medications. Following sequestrectomy, the patient had an uncomplicated post-operative healing five months following intervention. With increasing medications being used for a number of malignant conditions such as this, an awareness of less common complications such as ONJ amongst dental and medical specialties is highlighted in this case report.