ASTRO 2018: Radiation therapy makes low recurrence rates among some breast cancer patients even lower

Radiation therapy can lower the chance of cancer recurrence in patients with low-risk breast cancer following breast conservation surgery, according to data presented Oct. 21 at the American Society for Radiation Oncology (ASTRO) Annual Meeting in San Antonio, Texas.

The research represents a 12-year update from a randomized trial that compared cancer recurrence in patients with low-risk ductal carcinoma in situ (DCIS) after breast conservation surgery. The original study included more than 600 patients with tumors 2.5 cm or smaller. Twelve years after surgery, patients with low-risk DCIS who underwent whole breast radiation therapy (WBRT) and also took tamoxifen for five years had the lowest recurrence rates.

The authors noted that recurrence was unlikely in patients who received no further treatment following surgery—but undergoing WBRT did have a noticeable effect in making it even more rare.

“I think the most surprising thing was that the recurrence rate in patients randomized to receive radiation therapy was so low,” lead investigator Beryl McCormick, MD, of Memorial Sloan Kettering Cancer Center in New York City,  said in a prepared statement. “Radiation reduced recurrence by more than 70 percent, and this was a much more profound impact than we expected."

In the same statement, McCormick added that not all low-risk breast cancers are the same—patients should consult with their physician and it would be reasonable if they chose not to undergo WBRT.

“We found that radiation does significantly reduce the risk for recurrence, but you are starting with an extremely low recurrence rate even without radiation,” McCormick said. “Therefore, there should be a meaningful discussion between patient and doctor about whether additional treatment is something the patient wishes to pursue.”

The ASTRO Annual Meeting is Oct. 21-24 at the Henry B. Gonzalez Convention Center in San Antonio.