Dr. Tripathy on the Emergence of Genomics Research in Breast Cancer

Debu Tripathy, MD, professor, chairman, Department of Breast Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses the emergence of genomics research in breast cancer.

Across the landscape of breast cancer, general treatment indications can be drawn from some rare mutations seen across various tumor types, Tripathy says. Though NTRK mutations are rare in breast cancer, the detection of these alterations could lead to the utilization of larotrectinib (Vitrakvi) or entrectinib (Rozlytrek), Tripathy explains.

Additionally, HER2 mutations can be observed in patients even if conventional testing shows HER2-negative tumors, Tripathy says. This can occur if the HER2 gene is turned on and mutated, leading to an active receptor on a HER2-negative tumor, Tripathy adds. HER2 mutations become more common in patients who have received endocrine therapy, Tripathy notes.

In patients with lobular cancers who are administered endocrine therapy, approximately 10% present with HER2 mutations, and research has shown these patients respond to certain HER2-targeting agents, Tripathy continues. If the tumor is hormone receptor–positive, response rates of close to 50% can be seen in this patient population with the use of neratinib (Nerlynx) in combination with trastuzumab (Herceptin) or fulvestrant (Faslodex), Tripathy adds. Though there has not yet been FDA approval, there are ongoing studies examining these potential combinations, Tripathy concludes.