Breast Cancer

Washington, DC—Among women with HER2-positive metastatic breast cancer, patients with the highest expression of HER2 had the best outcomes in treatment with ado-trastuzumab emtansine (T-DM1; Kadcyla), according to a biomarker analysis of the phase 3 EMILIA trial which was presented at the 2013 American As­sociation for Cancer Research annual meeting.

Histone deacetylase (HDAC) inhibitors may have a future in the targeted treatment of triple-negative breast cancer, if the results of in vitro studies can be replicated clinically.

Eribulin mesylate (Halaven) is currently used in patients with metastatic breast cancer whose disease has progressed on other treatments, but the drug may be useful in earlier lines of therapy.

Some patients who test HER2 negative by conventional tests may still benefit from anti-HER2 agents. This is the conclusion of a study that examined HER2 mutations in detail which was presented by Ron Bose, MD, PhD, Assistant Professor, Oncology Division, Department of Medicine, Washington University School of Medicine in St Louis, MO.

The incidence of false-negative immunohistochemistry (IHC) is only 1% in patients with primary breast cancer, according to a prospective multicenter Canadian study presented at the meeting.

For patients with HER2-positive early breast cancer, 1 year of treatment with trastuzumab (Herceptin) remains the standard of care, according to the HERA trial and a subanalysis of the PHARE study.

Determining HER2 status utilizing novel central laboratory testing techniques has been shown to be more reliable than routine local HER2 testing, such as immunohistochemistry or in situ hybridization.

>The molecular make-up of triple- negative breast cancer is becoming better understood, and new evidence suggests that the main biologic pathways can be targeted with drugs, according to Justin Balko, PharmD, PhD, Postdoctoral Research Fellow and Researcher, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville.

San Antonio, TX—Studies have suggested that musculoskeletal toxicity associated with aromatase inhibitor therapy can lead to noncompliance in up to 33% of women with breast cancer. A new, large cohort study at a single regional cancer center showed that the rate of musculoskeletal toxicity in women with early breast cancer who were treated with endocrine therapy was 64%.