Hypofractionated radiation is preferred for early-stage breast cancer

Patients with early-stage breast cancer who received a short but high-dose course of hypofractionated whole-breast irradiation (HF-WBI) had equivalent cosmetic, functional, and pain outcomes as those who received the longer but lower dose conventionally fractionated whole-breast irradiation (CF-WBI), according to a study posted online June 15, 2016 in the journal Cancer.

“There were no significant differences between the treatment arms for any patient-reported outcomes at baseline, 6 months, 1 year, or 3 years,” said the study’s lead author Cameron Swanick, MD, resident in Radiation Oncology at The University of Texas MD Anderson Cancer Center, in Houston, TX.

“At 2 years, outcomes from the Functional Assessment of Cancer Therapy Breast trial outcome index were modestly higher in the hypofractionated group,” she added.

Given that the shorter course of HF-WBI shows equivalent outcomes but has a more convenient treatment schedule than the longer course of CF-WBI, the authors suggested that HF-WBI should be the preferred option for patients.

These researchers published an important, related study in October 2015 which showed that early-stage breast cancer patients who received HF-WBI experienced less acute toxicity and post-radiation fatigue compared with those treated with CF-WBI.

For the current prospective, unblinded trial, the researchers randomly assigned 287 women with stage 0 to stage II breast cancer to receive either CF-WBI (50 grays in 25 fractions) or HF-WBI (42.56 grays in 16 fractions) after breast-conserving surgery. All patients also received a boost dose—an additional high-dose treatment that targeted the tumor bed. Participants were at least 40 years old and most (76%) were overweight or obese.

After 2 years, subjects in the HF-WBI group averaged modestly better functional assessment scores, and their measures of functional status and breast pain improved with time. Physician-rated cosmesis evaluations rated the same for both treatment groups.

These results add to the growing body of evidence that strongly suggests that hypofractionation should be the preferred dosing regimen for early-stage breast cancer patients receiving WBI, the authors concluded.