Dr Tolaney on Frontline Treatment Approaches in HER2+ Breast Cancer

Sara M. Tolaney, MD, MPH, chief, Division of Breast Oncology, Susan F. Smith Center for Women's Cancers, associate director, Susan F. Smith Center for Women's Cancers, senior physician, Dana-Farber Cancer Institute, associate professor of Medicine, Harvard Medical School, discusses standard frontline treatment approaches for patients with HER2-positive breast cancer.

When a patient presents with newly diagnosed HER2-positive breast cancer, the initial focus is on determining the tumor's size and whether there is lymph node involvement, Tolaney begins. If the tumor is less than 2 cm, and there is no evidence of lymph node involvement, the typical approach is to proceed with upfront surgery, she says. Post-surgery, if the patient is confirmed to have stage I or II HER2-positive cancer, treatment options include paclitaxel combined with trastuzumab (Herceptin) or ado-trastuzumab emtansine (Kadcyla). Both options are considered appropriate for stage I disease, allowing the clinician to choose the most suitable therapy based on the patient's specific circumstances, she explains.

For patients with larger tumors greater than 2 cm—or with lymph node involvement, the treatment strategy shifts toward administering therapy before surgery, Tolaney states. Preoperative therapy often consists of a combination of docetaxel, carboplatin, trastuzumab, and pertuzumab (Perjeta; TCHP), she details. Although some treatment regimens historically included anthracyclines, most clinicians have moved away from this approach, preferring to administer TCHP for 6 cycles, Tolaney says.

Following preoperative treatment, the patient undergoes surgery to assess the tumor's response to the therapy, she continues. If residual disease is found, the standard course of action is to administer 14 doses of T-DM1. Conversely, if the patient achieves a pathologic complete response, the treatment plan typically involves continuing with HER2-directed antibodies to complete a full year of therapy, Tolaney states.

The decision-making process in the upfront setting is guided by the patient's initial clinical and anatomical risk, with the goal of optimizing outcomes while minimizing unnecessary treatment. Each step, from assessing tumor size and lymph node involvement to tailoring therapy based on response, is designed to ensure the most effective and individualized care for patients with HER2-positive breast cancer, Tolaney concludes.