Titles and Affiliations
Professor of Pathology
Harold E. Lee Chair in Cancer Research
Director of Breast Cancer Analysis Lab
Keck School of Medicine
Research area
Refining breast cancer biomarkers for predicting response to targeted therapies in order to improve personalized medicine.
Impact
Breast cancer molecular markers, such as HER2, estrogen receptor, and progesterone receptor, are used to select treatments for patients. Because they act as major drivers of breast cancer, they have been successful therapeutic targets. Dr. Press and his team are working to improve treatment response using known biomarkers and to identify new breast cancer biomarkers to help guide treatment decisions and reduce drug resistance. This work may improve patient selection for existing therapies and identify new targets for therapy.
Progress Thus Far
Dr. Press and his team are involved in several research projects that could impact personalized medicine for breast cancer patients. Dr. Press is studying HER2 gene amplification status, which leads to an overproduction of HER2, as well as hormone receptor status. He and his team are investigating associations of these molecular alterations with responsiveness to various treatments as measured by clinical outcomes. The team recently observed HER2 protein on normal eye cells that may explain the eye-related side effects sometimes seen with newer HER2-targeted antibody-drug conjugates, such as trastuzumab deruxtecan (T-DXd, Enhertu®). Dr. Press’s laboratory serves as the center for several breast cancer clinical trials of novel therapies, including a trial of T-DXd in patients whose breast cancers are considered HER2-low. Treating these breast cancers opens a new therapeutic option to many patients, including some whose breast cancer had been classified as triple-negative (TNBC), for which there are limited treatment options. Dr. Press has also continued long-standing collaborative studies to identify genetic risk factors in those without a hereditary predisposition to the disease.
What’s next
Dr. Press will continue to investigate why standard trastuzumab treatment is largely ineffective in patients with only low-level HER2 amplification, a finding that helps explain why HER2-low disease was historically considered ineligible for HER2-targeted therapy. In contrast, a newer HER2-targeted drug, T-DXd, has proven effective in these same HER2-low patients. Dr. Press’s team is developing new laboratory tests to better define exactly which patients with HER2-low disease are most likely to benefit from T-DXd treatment. Dr. Press will continue leading his laboratory’s role in ongoing breast cancer clinical trials and collaborative genetic studies aimed at better understanding breast cancer risk across different populations.
Biography
Dr. Press is a Professor in the Department of Pathology and holds the Harold E. Lee Chair in Cancer Research at the University of Southern California’s Norris Comprehensive Cancer Center. Dr. Press is a board certified pathologist, directs the USC Breast Cancer Analysis Laboratory as well as the Central Laboratory for the Translational Research In Oncology (TRIO)/Cancer International Research Group (CIRG), and is Leader of the USC Clinical Laboratories.
His laboratory evaluates prognostic and predictive markers used in making treatment decisions for women with breast cancer. It has served as the Central Laboratory for either retrospective or prospective analyses of tissue specimens for 18 clinical trials that collectively accrued more than 13,000 patients. Dr. Press’s area of research interest is in molecular alterations of breast and gynecologic cancers, especially those that have the potential to be important in either diagnostic or therapeutic decision-making for patient management. His research has been continuously funded by research grants for more than 25 years. He is the author or co-author of more than 200 peer-reviewed publications. The most prominent area of activity for his laboratory has been in the study of the human epidermal growth factor receptor type 2 (HER2) in breast and other cancers. He published his first paper in this area in 1989 (Science 244: 707-712) and his laboratory is still actively contributing to this area as well as to the conduct of clinical trials evaluating HER2 as a target for therapy.
