Radiation Prevents Recurrence in Ductal Carcinoma In Situ
Treatment lowers five-year event risk in high- and low-risk non-invasive breast cancer patients
THURSDAY, Sept. 21 (HealthDay News) -- Radiation therapy helps protect older women with ductal carcinoma in situ from invasive breast cancer and mastectomy, researchers report in the Sept. 20 issue of the Journal of the National Cancer Institute.
Benjamin D. Smith, M.D., of the Yale University School of Medicine in New Haven, Conn., and colleagues analyzed Medicare data on 3,409 women aged 66 or older who underwent conservative surgery for non-invasive breast cancer between 1992 and 2000.
Those who had radiation therapy were at lower risk for either later ipsilateral in situ or invasive breast cancer and mastectomy than those without radiation therapy. High-risk patients had a 13.6 percent five-year cancer recurrence risk without radiation therapy, versus a 3.8 percent risk with radiation therapy.
Low-risk patients without radiation therapy had an 8.2 percent five-year recurrence risk, versus a 1.0 percent risk with radiation. The authors estimate that one five-year recurrence could be prevented for every 11 high-risk patients aged 66 to 79 years and 15 to 16 low-risk patients treated with radiation.
"For older women with ductal carcinoma in situ, radiation therapy appears to confer a substantial benefit that remains meaningful even among low-risk patients," the authors write.