Dr. O'Shaughnessy Discusses New Developments in Molecular Profiling in Breast Cancer

Joyce A. O'Shaughnessy, MD, Texas Oncology-Baylor Charles A. Sammons Cancer Center, discusses new developments in molecular profiling in patients with metastatic breast cancer.

O’Shaughnessy discusses a clinical trial examining the efficacy of letrozole in patients with ER-positive metastatic breast cancer with or without dasatinib. Dasatinib was found to be beneficial in terms of improving duration of response, she adds. However, using the phosphoprotein assay, researchers found that activation of the HER3 protein in patients was a poor prognostic factor in benefitting from letrozole.

The group of patients with HER3 expression benefitted from dasatinib in this study. O'Shaughnessy explains that the phosphoprotein assay can be beneficial in determining which patients will benefit from anti-estrogen agents.