Hypofractionated radiation in older women with breast cancer

American Society of Radiation Oncology Choosing Wisely campaign recommends hypofractionated radiation and against routine use of intensity-modulated radiation therapy (IMRT) in early-stage estrogen receptor-positive breast cancer. We analyzed guideline recommendation adherence and financial implications in a modern Medicare cohort of women treated across the southeastern United States.

Our study population comprised Medicare patients over 65 years of age with breast cancer diagnosis from 12 cancer centers in the Southeast United States with stage 0-II breast treated with lumpectomy from 2012 to 2015. Hypofractionation was defined as 4 or fewer weeks of radiation treatments. Factors associated with utilization of hypofractionation and IMRT were identified using Poisson regression. Median costs during radiation treatments were compared for hypofractionation and IMRT.

In older women (median age 71), 75% were treated with conventional fractionation, and 20% received IMRT. Hypofractionated women were more likely to have a positive estrogen(ER) or progestorone(PR) receptor status, lower comorbidity scores, and be treated at a high volume center (all P < 0.05). IMRT was utilized in 20% of patients and was more common in women treated with conventional fractionation (P < 0.001). Positive ER/PR status (P < 0.001) and utilization of hormonal blockade (P = 0.02) were associated with increased utilization of IMRT.

In an older cohort of patients with early-stage breast cancer, a majority were treated with conventional fractionated radiation, while approximately 20% were treated with IMRT. Both of which were associated with increased cost relative to hypofractionation.