(HealthDay News) – Treatment with radiation therapy after excision of ductal carcinoma in situ (DCIS) in women aged 60 is associated with a slight improvement in survival, but may increase the likelihood of eventual mastectomy, according to a study published in the February 1 issue of Cancer.
Rinaa S. Punglia, MD, MPH, of the Dana-Farber Cancer Institute/Brigham and Women’s Hospital in Boston, and colleagues studied the influence of treatment outcomes using a Markov decision model designed to simulate the clinical course of DCIS for a woman aged 60 who has undergone excision, with and without the addition of radiation therapy. They examined the risk of local recurrence, the likelihood of invasive disease, surgery choices after recurrence, and patient age at diagnosis in relation to treatment outcomes.
Using sensitivity analyses, the researchers found that radiation therapy after DCIS for a woman aged 60 improved overall disease-free survival by 2.1 months, while decreasing the chances of keeping both breasts by 8.6%; the latter decrease was due to a higher likelihood of eventual invasive recurrence or new breast cancer diagnosis requiring mastectomy. With increasing age at diagnosis, the difference in outcomes between the treatment strategies became smaller.
“Radiation for DCIS is prophylactic; it reduces the risk of invasive recurrence, which is the only lethal form of breast cancer, while increasing the probability of eventual mastectomy,” the authors write. “The absolute magnitude of both effects is modest, such that personal patient preferences should drive decision making.”