Dr. O'Shaughnessy on Using Phosphoprotein Assays to Personalize Treatment for Breast Cancer

Joyce A. O'Shaughnessy, MD, Texas Oncology-Baylor Charles A. Sammons Cancer Center, discusses how the results of phosphoprotein assays can impact treatment decisions for select patients with advanced breast cancer.

Personalizing treatment for patients with triple-negative breast cancer (TNBC), as well as the heavily pretreated ER-positive subtype, has always been difficult for oncologists, O’Shaughnessy explains. Also, these groups are often diagnosed with widespread liver metastases. Researchers have sought to determine if the androgen receptor (AR) has a potential role in this occurrence.

Anecdotally, O’Shaughnessy discusses a patient with TNBC who did not carry the AR protein but did have high levels of phosphorylation of AR. Though the clinical implications of this are unclear, O’Shaughnessy predicts that AR is active in this case. In patients with liver metastases, oncologists often discover concentrated, high levels of phosphorylation of AR, which could be driving the PI3K pathway. This could help drive therapeutic strategies for these patients, O’Shaughnessy adds.