Catherine Van Poznak, MD

There are still questions to be answered about the use of osteoclast inhibitors in the care of patients with breast cancer. The optimal duration and dosing schedule and how to improve treatment compliance are important issues to address.

Breast cancer is the most common noncutaneous cancer among women.[1] In 2009, an estimated 190,000 new cases occurred in the US. The 5-year survival rate for early-stage breast cancer has improved from approximately 63% in the early 1960s to almost 90% today, mainly as a result of early detection and treatment.[2] The improvement in survival from breast cancer treatments, however, which include chemotherapy, endocrine therapy, and/or ovarian ablation, does not come without the cost of potentially significant effects on bone mineral density (BMD).[3-5] The risk of having low bone mass increases significantly with age, as does the risk of developing breast cancer; consequently, the two diagnoses often overlap in the same individual. Additionally, women with breast cancer may be at increased risk for osteoporosis due to the effect on bone of certain anticancer therapies. Hence, some women with breast cancer may be at increased risk of osteoporosis.

Cases of osteonecrosis of the jaw (ONJ) have been reported with an increasing frequency over the past few years. ONJ is most often identified in patients with cancer who are receiving intravenous bisphosphonate therapy but it has also been diagnosed in patients receiving oral bisphosphonates for nonmalignant conditions. The condition involves exposed bone of the maxilla or mandible. Although it is often associated with a recent dental surgical procedure, spontaneous ONJ can also occur. Patients commonly present with symptoms. Through case reporting and clinical experience, there is a suggestion that the incidence of ONJ in patients with cancer receiving intravenous bisphosphonates ranges between 1% and 10%. Management of ONJ focuses on maximizing oral health, conservative actions with mouth rinses, antibiotics, and avoidance of unnecessary invasive dental procedures. The currently available data on ONJ are reviewed here.

The need for accurate detection of HER2 status is becoming more apparent, as therapeutic decisions are influenced by this information in both the adjuvant and advanced-stage setting. Since the US Food and Drug