Wendy A. Woodward, MD, PhD, professor and chief, Clinical Breast Radiotherapy Service, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, discusses radiotherapy in breast cancer.
The EORTC 22922 trial recently presented at the 2018 ASCO Annual Meeting randomized patients with stage I-III disease who were node-positive and had central or medial tumors to regional nodal irradiation. The primary endpoint was overall survival. The primary finding showed that at 15 years, breast cancer mortality was improved by 3.8% in the patients who received regional nodal irradiation, says Woodward. These results, in combination with another trial, demonstrate that radiotherapy has a systemic effect in these early-stage patients, explains Woodward.
However, one of the challenges of regional nodal irradiation is the impact on the heart. Though the trial did not see worse cardiac outcomes, they did see an increased number of deaths in the regional nodal irradiation arm from unknown causes. In contemporary practice, Woodward states that there is a lot of effort that goes into reducing the dose to the heart. That can be done with a deep inspiration breath hold and more advanced technologies, says Woodward. In current practice, physicians estimate the risk of a heart event to be less than 1%.