Radiation Benefit May Be Predictable for Patients With DCIS

Treatment for patients with ductal carcinoma in situ (DCIS) is getting more individualized, thanks to a team of researchers at Brigham and Women’s Hospital (BWH) and the Dana-Farber Cancer Institute.

The researchers discovered a set of three measurable risk factors that can help predict survival benefits that radiation therapy would offer after breast-conserving surgery for DCIS.

“Radiation therapy after breast cancer surgery has become a widely accepted treatment option for patients undergoing breast-conserving therapy with DCIS. Our results provide information that can guide individual treatment options and better predict survival benefit from radiation therapy based on an individual’s case,” Mehra Golshan, one of the study’s senior authors, explained in a statement.

Golshan, the Al-Tuwaijri Family Distinguished Chair of Surgical Oncology at Dana-Farber/Brigham and Women’s Cancer Center, and colleagues analyzed SEER data from 32,144 patients diagnosed with DCIS between the years 1988 and 2007.

Of this group, 20,329 patients were treated with radiation therapy following breast cancer surgery and the remaining 11,815 only underwent breast cancer surgery. At the conclusion of their retrospective, longitudinal, NIH-funded study, the research team found low cancer mortality rates at 10-years for both groups: 1.8 percent for patients who received radiation therapy and 2.1 percent for those who did not receive the therapy. There were 304 breast cancer—specific deaths overall.

Each patient was assigned a validated prognostic score using a 0-6 scale based on three risk factors: nuclear grade, patient’s age and tumor size. A higher nuclear grade, younger age, and/or larger DCIS received a higher score and vice versa.

They found that radiation therapy resulted in a significant survival benefit for patients with higher scores. Patients who scored a four or five on the prognostic tests displayed a 70 percent reduction in breast cancer mortality if they were treated with radiation therapy after surgery. Patients with lower scores from both the radiation and surgery-only cohorts showed no significant difference in breast cancer mortality.

Although DCIS results in low cancer mortality overall, officials estimate that nearly 60,000 of Americans will be diagnosed with DCIS in 2016 — a rate that has tripled in the past three decades.

“Using three factors that are routinely measured, we can predict whether there will be a survival benefit or no survival benefit for patients receiving radiation therapy,” lead author Yasuaki Sagara, of the BWH Department of Surgery and Dana Farber/Brigham and Women's Cancer Center, said in a statement. “Our finding suggests, for the first time, that patients with more aggressive cancer who are at higher risk may actually live longer if they are treated with radiation therapy.”

Nonetheless, study investigators advised thorough counseling about the benefits and risks of radiation therapy for patients with DCIS who are seeking treatment options.

Sagara Y, Freedman RA, Vaz-Luis I, et al. Patient prognostic score and associations with survival improvement offered by radiotherapy after breast-conserving surgery for ductal carcinoma in situ: a population-based longitudinal cohort study. J Clin Oncol. 2016;34(11):1190-1196.