Current Research on Identifying Biomarkers in Breast Cancer

Elizabeth Mittendorf, MD, PhD, director of the Breast Oncology Program at the Susan F. Smith Center for Women’s Cancers at Dana-Farber Cancer Institute, discusses the importance of identifying biomarkers in patients with breast cancer. Current studies are looking at PD-L1 as a possible biomarker, but Mittendorf believes there may be other biomarkers that will prove to be more reliable.

When using antibodies to target the PD-1 and PD-L1 axes, the thought has been that PD-L1 expression is important for the response, Mittendorf explains. However, PD-L1 may not be the best biomarker because it is incredibly dynamic, which may cause issues in predicting response in patients.

While many ongoing trials are focusing on PD-L1 biomarkers, other trials looked at PD-L1 cells in the microenvironment as opposed to on the tumor. Additional data is suggesting that the presence of stromal lymphocytes may be able to predict response to therapy.