The American Society of Clinical Oncology (ASCO) recently released updated guidelines for the treatment of advanced HER2-negative breast cancer. The Journal of Clinical Oncology will publish the new guidelines, which include hormone therapy and sequential chemotherapy.
One of the ways breast cancers are classified is according to HER2 status, a measure of the amount of the HER2 protein found on the surface of the cancer cells. (HER2 is also known as human epidermal growth factor receptor 2). In normal cells, HER2 helps to control cell growth. Cancer is considered HER2 positive when it has an abnormal amount of HER2, which can cause cells to grow more quickly and be more likely to spread to other parts of the body. Cancers that don’t overexpress HER2 are considered HER2 negative.
The distinction between HER2-positive and HER2-negative breast cancer is important in treatment planning. There are drugs available for HER2-positive disease that specifically target the HER2 protein; HER2-targeted therapy, however, is not effective in HER2-negative breast cancer.
To describe current treatment options for HER2-negative breast cancer, ASCO recently released updated guidelines. An expert panel worked together to finalize the guidelines, which are based on a review of research from 1993 until now and focus on progression-free survival, response, quality of life, and side effects.
The panel used evidence from 79 studies of treatment of advanced HER2-negative breast cancer. Based on their review of these studies, they made the following guideline recommendations:
- For patients with advanced breast cancer that is HER2-negative, but estrogen-receptor positive, the guidelines recommend hormone, or endocrine, therapy instead of chemotherapy as first-line treatment. The guidelines, however, make an exception for life-threatening disease and disease that’s resistant to hormone therapy; in these cases first-line chemotherapy might be the best option.
- When chemotherapy is used in advance HER2-negative disease, the guidelines recommend single-agent chemotherapy that’s administered sequentially, instead of combination chemotherapy.
- The panel didn’t recommend an optimal chemotherapy (first line or later). They advised physicians and patients to choose treatment according to factors including previous treatment, toxicity, outcome, other health conditions, and patient preference.
- The updated guidelines do not include a general recommendation for the biologic, or targeted, therapy Avastin® (bevacizumab), as other drugs in this class have yet been shown to improve outcomes for patients with HER2-negative breast cancer. They do state that Avastin can be considered as single-agent therapy for patients who have immediately life-threatening disease or severe symptoms. No other targeted agents are recommended, either for use in combination with chemotherapy or instead of chemotherapy.
In a press release from ASCO, Ann H. Partridge, MD, MPH, co-chair of ASCO’s expert panel that developed the guidelines, explained that their goal is improving patient outcomes. “In releasing this guideline, our aim is to improve both the length and quality of patients’ lives,” she said. “The guideline will help doctors and patients choose the best therapy based on what treatment would be most tolerable and convenient for the patient.”
 Partridge AH, Rumble RB, Carey, LA, et al. Chemotherapy and Targeted Therapy for Women With Human Epidermal Growth Factor Receptor 2–Negative (or unknown) Advanced Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline. Journal of Clinical Oncology [early online publication]. September 2, 2014.
ASCO Issues New Guideline on Treating Patients with Advanced, HER2-negative Breast Cancer. New Release. The American Society of Clinical Oncology website. Available at: http://www.asco.org/press-center/asco-issues-new-guideline-treating-patients-advanced-her2-negative-breast-cancer. Accessed September 8, 2014.