Could radiation therapy before surgery improve survival rates?
New research has found that estrogen receptor positive breast cancer patients who have radiation therapy before surgery are less likely to develop a second primary tumour.
The Moffit Cancer Center research was published in the journal, Breast Cancer Research, and examined the impact of neoadjuvant radiation therapy (radiation before surgery) in early stage breast cancer.
The researchers compared the overall survival and the time to diagnosis of a second tumour in more than 250,000 breast cancer patients recorded in the American National Cancer Institute database.
They looked at women who had been diagnosed between 1973 and 2011 with early-stage breast cancer. The analysis included 2,554 women who received localized breast radiation therapy before surgery and 247,641 women who received localized breast radiation therapy after surgery.
The researchers discovered that radiation therapy prior to surgery was beneficial for patients who had estrogen receptor (ER) positive breast cancer.
Women with ER-positive breast cancer who had radiation therapy before surgery had a significantly lower risk of developing a second primary tumour than patients who had radiation therapy after surgery.
The study found that this was true for patients who underwent both partial and complete mastectomies. They also found that delaying surgery due to neoadjuvant radiation therapy was not detrimental to survival.
Researcher, Dr Heiko Enderline, says a number of recent studies have suggested that radiation therapy may re-educate and stimulate the immune system to target cancer cells.
“The observed benefit of neoadjuvant radiation therapy aligns with the growing body of literature of the immune activation effects of radiation, including shrinking of untreated metastases outside the radiation field,” he says.
But he warned that further randomised clinical trials were needed to confirm the benefit of neoadjuvant radiation therapy.
“Historic data indicate that disease-free survival is significantly increased when radiation therapy is applied before surgery rather than after surgery, especially for ER-positive patients. These findings are worthy of a prospective clinical trial to confirm potential benefits of neoadjuvant vs. adjuvant radiation, and to identify the potential contribution of radiation-induced immunity to vaccinate against future disease,” Dr Enderling says.