Hypofractionated WBI Slow to Catch On

January 2, 2015

Despite having advantages over conventional whole breast irradiation, hypofractionated WBI is used by only a third of patients who would benefit.

The uptake of hypofractionated whole breast irradiation (WBI), which is a faster and less costly treatment than conventional WBI, has been slower than expected among the select group of US women with early-stage breast cancer who would benefit, researchers report.

Writing in JAMA, scientists from the University of Pennsylvania Perelman School of Medicine, Philadelphia, described a situation where the expert guidelines from 2011 recommending hypofractionated WBI for certain cases have not been followed by the masses.

Key Points:

- Patients with early-stage breast cancer who opted for breast-conserving treatment have been slow to receive hypofractionated WBI.

- Hypofractionated WBI is a shorter, less costly radiation treatment than conventional WBI.

High-quality evidence supports using hypofractionated WBI for a select group of patients with early-stage breast cancer, with the treatment also permitted for other patients, the authors explained. However, those who would benefit from the treatment seem to be sticking to the conventional WBI treatment course, which lasts 5 to 7 weeks versus the 3 to 5 weeks involved in hypofractionated WBI.

To better understand which treatment options women are choosing, researchers retrospectively evaluated claims data of women with incident early-stage breast cancer treated with lumpectomy and WBI from 2008 and 2013 and classified the data into 2 cohorts. The hypofractionation-endorsed cohort (n = 8924) included patients aged 50 years or older without prior chemotherapy or axillary lymph node involvement. The hypofractionation-permitted cohort (n = 6719) included women younger than 50 years or those who had prior chemotherapy or axillary lymph node involvement.

Slightly more than a third of all patients who fall within the parameters endorsed for the faster procedure go with that option, the authors found. Still, the use of hypofractionated WBI has increased from 10.6% in 2008 to 34.5% in 2013 in the endorsed cohort and from 8.1% in 2008 to 21.2% in 2013 in the permitted cohort, the authors reported. In terms of cost, hypofractioned WBI is less expensive, the authors said. The adjusted mean total health care expenditures in the 1 year after diagnosis were $28,747 for hypofractionated and $31,641 for conventional WBI in the hypofractionation-endorsed cohort and $64,273 for hypofractionated and $72,860 for conventional WBI in the hypofractionation-permitted cohort.

“In the United States, although the 2011 practice guidelines concluded that hypofractionated and conventional WBI were ‘equally effective for in-breast tumor control and comparable in long-term side effects’ for selected women, the guidelines stopped short of recommending hypofractionated WBI as a care standard to be used in place of conventional WBI. The absence of a clear recommendation may have contributed to slower uptake of hypofractionation in the United States than in other countries. In 2013, we observed more pronounced uptake of hypofractionation; evaluation of future treatment patterns will be important to document whether or not this trend reflects the beginning of more widespread adoption,” the authors wrote.