Dr. Tripathy on Markers of Resistance in Breast Cancer

Debu Tripathy, MD, co-leader, Women's Cancer Program, University of Southern California Norris Comprehensive Cancer Center, discusses markers of resistance in patients with HER2+ breast cancer.

Tripathy says mutations in the PI3K enzyme, which is part of the signaling pathway, appears to be an indicator for worse outcome in response to trastuzumab. The mutation may also identify a group of patients that responds best from combination treatment but researchers are still unsure.

As more HER2-targeted therapies are being added to this space, outcomes will be improved, Tripathy says. However, patients still become resistant. In the future, Tripathy says, more potent combinations will have to be developed and more pathways will have to be discovered.