In April 2020, at the height of the first wave of the COVID-19 pandemic, the 5-year efficacy results of the FAST-Forward trial were published showing that 1 week of whole breast radiotherapy was noninferior to the standard schedule given over 3 weeks for women with early-stage breast cancer after primary surgery.

The study compared 40 Gy in 15 fractions over 3 weeks, 27 Gy in five fractions over 1 week, and 26 Gy in five fractions over 1 week to the whole breast (>93% of cases) or chest wall. The 26 Gy in five fractions over 1 week regimen was noninferior to the standard and was safe in terms of normal tissue effects up to 5 years. Interestingly, patient and photographic assessments suggested worse normal tissue effects for 27 Gy compared to 40 Gy, but not for 26 Gy compared to 40 Gy.

“This regimen of 26 Gy in 1 week looks to be equivalent and more convenient for patients,” according to Wendy Woodward, MD, PhD, of University of Texas M.D. Anderson Cancer Center, Houston, Texas. “The question then becomes: Should we adopt this universally now or wait for more data including longer follow-up?”

An SABCS 2021 debate, One Week of Whole Breast RT is the New Standard of Care, will address that question. Dr. Woodward will moderate the debate on Friday, Dec. 10 at 11:30 am CT.

Charlotte Coles, MBChB, PhD, Professor of Breast Cancer Clinical Oncology and Deputy Head of Department of Oncology at the University of Cambridge in the UK, will present the “Pro” argument, and Julia White, MD, Professor and Vice Chair Clinical Research at the Stefanie Spielman Comprehensive Breast Center at Ohio State University, will present the “Con” argument.

According to Dr. Woodward, it used to be that all early-stage breast cancer treated with lumpectomy would be followed with 5 or 6 weeks of radiation to the whole breast. Years ago, studies done in Canada and the United Kingdom developed and tested a 3-week radiation schedule that delivered an equivalent dose.

“The one challenge that gives people a little bit of pause is that a bigger radiation dose per fraction carries more risk for late toxicity,” Dr. Woodward said.

However, the studies of the 3-week regimen had 10 years of data showing the efficacy of the schedule with no increase in late recurrence of cosmetic toxicities.

“Now there are some who think we should adopt this 1-week schedule immediately and that it is harsh to tell patients that we have to have another trial of the 1-week schedule or wait 10 years before adopting this,” Dr. Woodward said. “There are compelling arguments on the other side as well.”

This debate has received even greater attention in the time of the COVID-19 pandemic.

“We want to reduce the time people spend in facilities without compromising care,” Dr. Woodward said. “I think that may have pushed people to move to this schedule sooner than we might have in normal times.”

Dr. Woodward hopes that, after listening to the debate, participants will be able to appreciate some of the nuances of the discussion.

“It is not as simple as saying 1 week is just as good,” she said. “For many, it may be reasonable to choose 1 week, but we want to help our patients make educated decisions.”