There are now several agents approved for the treatment of patients with HER2-positive breast cancer, placing the focus on the sequencing of therapies, which is largely driven by stage of disease and hormone receptor status, said Harold Burstein, MD, at the 2017 Lynn Sage Breast Cancer Symposium.
About 1 in 5 of the 250,000 new breast cancers diagnosed every year is HER2 positive. The disease used to carry a far worse diagnosis, and has gone from “worst to first” because of the success of the monoclonal antibody drug trastuzumab (Herceptin) in combination with chemotherapy, said Burstein. Disease-free survival rates have increased dramatically since trastuzumab was introduced in 1998, and without significant toxicity from the drug.
In general, about half of diagnoses are stage I. Though HER2-positive cancers are more common in young women, they can occur at any age. “Patients with stage I disease are doing very well with simple chemotherapy and trastuzumab and need nothing further,” Burstein, of the Dana-Farber Cancer Institute, said at the symposium, which was sponsored by Northwestern University’s Robert H. Lurie Comprehensive Cancer Center.
Patients with more advanced disease may get additional benefits from the use of 2 recently agents: pertuzumab (Perjeta) and neratinib (Nerlynx). Pertuzumab was approved for patients with HER2-positive metastatic breast cancer in 2012 and for neoadjuvant breast cancer treatment in 2013. Neratinib was recently indicated as an adjuvant treatment of early stage HER2-positive breast cancer following 1 year of trastuzumab in July.
Burstein noted that more research needs to be done to determine where pertuzumab and neratinib are best incorporated into treatment regimens; currently, he recommends adding pertuzumab to trastuzumab and chemotherapy for stage II or III disease, and adding adjuvant neratinib at the beginning of year 2 for ER-positive, HER2-positive tumors following one year of trastuzumab….