Clinical trial underway eliminating radiation for HER2 breast cancer

University of Kansas (KU) Cancer Center researchers have launched a clinical trial eliminating radiation therapy from treatment for an invasive type of breast cancer that affects nearly one-fifth of breast cancer patients, according to a KU news release.

Currently, Melissa Mitchell, MD, PhD, with KU Cancer Center and colleagues are recruiting post-menopausal women at least 50 years old who are in the early stages of human epidermal growth factor receptor 2 (HER2) positive invasive ductal carcinoma and also have clear lymph nodes. These patients will choose whether they want to be in the intervention group (no radiation) or the control group, who will receive care that including radiation.

Those who opt not to receive radiation after lumpectomy will undergo follow-up exams every three months for five years. The exams will include a mammogram or MRI, and patients will fill out a survey grading their quality of life and cosmetic aspects of their treatment.

"We hope to find that without radiation, patients do fantastic, that they do not have a recurrence—and all while having less risk of side effects, including heart and lung damage," Mitchell said.

Part of the reasoning behind this trial, according to Mitchell, is the addition of breakthrough drugs which shut down the HER2 protein, into chemotherapy treatment plans. The result has seen recurrence of this form of cancer cut by more than half.

"The treatment drugs have just become so effective that it made us think that maybe we could scale back and spare patients the side effects of radiation," said Melissa Mitchell, MD, PhD, with KU’s Cancer Center.

Those potential side effects include swelling of the breast, dryness itching and fatigue. In some cases, though rarer, radiation has been connected to secondary cancer. The treatment requires frequent time away from work and has been known to cause long-term heart and lung damage.