A study found that a whole-breast radiation schedule that is shorter than the conventional regimen offered the same cosmetic outcomes and slightly better functional outcomes than the conventional regimen.
The research was published online on June 15, 2016 by the journal Cancer. Read the abstract of “Longitudinal analysis of patient-reported outcomes and cosmesis in a randomized trial of conventionally fractionated versus hypofractionated whole-breast irradiation.”
After lumpectomy to remove early-stage breast cancer, radiation therapy often is used to reduce the risk of recurrence. Whole-breast radiation therapy after breast cancer surgery is usually given as one treatment per day, 5 days a week, for 5 to 7 weeks. A Gray is the way radiation oncologists measure the dose of radiation therapy; if you’re on a 5-week treatment schedule, 50 Gray is the usual amount given during the 5 weeks (2 Gray at each treatment). A supplemental “boost” dose may be included at the end of the regimen that targets the area where the cancer was.
Radiation treatment schedules have been developed based on research results. But a 5- to 7-week nearly daily commitment may be difficult for some women, especially if they live far away from a treatment center.
Doctors have studied a different radiation therapy schedule that involves fewer treatments with higher doses of radiation at each treatment, but the same total radiation dose. So this schedule puts the same radiation dose into a 3- to 5-week schedule. Giving the traditional amount of radiation in a shorter time period is called hypofractionated whole-breast radiation.
A hypofractionated whole-breast radiation schedule is appealing to doctors and people getting radiation for several reasons:
- convenience: arranging daily trips to get treatment can be a problem for some women; fewer treatment days or a shorter period of time may be easier to schedule
- if radiation is more convenient to schedule, it’s probably easier for women to get all the recommended radiation therapy
In 2011, the American Society for Radiation Oncology (ASTRO) released guidelines on hypofractionated whole-breast radiation (PDF) and said the technique was as safe and effective as conventional whole-breast radiation for early-stage breast cancer after lumpectomy for women who meet the four criteria below:
- age 50 or older when diagnosed with breast cancer
- the cancer is stage T1 to T2, no cancer cells have been found in the lymph nodes, and the cancer has been removed with lumpectomy
- the cancer hasn’t been treated with chemotherapy
- the minimum and maximum doses of radiation are plus or minus 7% of the prescription dose
The guidelines also say that hypofractionated whole-breast radiation could be a good option for other women who don’t meet all four of the criteria, especially younger women.
Still, some doctors have been reluctant to use a hypofractionated radiation schedule. A 2014 study published in the Journal of the American Medical Association found that while use of a hypofractionated radiation schedule to treat breast cancer more than tripled from 2008 to 2013, it still wasn’t being prescribed as often as it could be.
In the study reviewed here, researchers from the University of Texas MD Anderson Cancer Center randomly assigned 287 women diagnosed with early-stage breast cancer to one of two radiation schedules after lumpectomy:
- a conventional schedule of a total of 50 Grays given in 25 treatments plus a boost dose (149 women)
- a hypofractionated schedule of a total of 42.56 Grays given in 16 treatments plus a boost dose (138 women)
All the women were age 40 or older and 76% were overweight or obese based on their body mass index.
The researchers collected information on how the women viewed the cosmetic and functional outcomes of the radiation treatment, as well as other quality of life factors before the study started, and then at 6 months, 1 year, 2 years, and 3 years after radiation treatment ended.
The two radiation schedules had the same outcomes before the study started and at 6 months, 1 year, and 3 years after the treatment ended.
Two years after treatment, women in the hypofractionated radiation group reported slightly better functional outcomes than women in the conventional schedule radiation group. This difference was small, but it was statistically significant. This means that the difference in functionality was probably because of the different radiation schedules and not just due to chance.
Both treatment groups had similar improvements in breast pain and functionality over time.
"This trial is particularly important because there is still some hesitation among clinicians in the U.S. about adopting the hypofractionated schedule," said lead author Cameron Swanick, M.D, radiation oncology resident at MD Anderson. "Because American patients tend to have a higher prevalence of obesity, and because prior trials excluded certain patients with high body mass index, there has been this concern that the shorter radiation treatment course may not be as safe for American patients."
The results of this study echo earlier results showing that hypofractionated radiation is as good as a conventional radiation schedule.
"Hypofractionated treatment, for appropriately selected patients, is an acceptable alternative and obviously is very desirable from the patient standpoint, treatment lasting 4 weeks as opposed to 6 weeks is something patients always appreciate as long as it's just as effective," said Bruce Haffty, M.D., of the Rutgers Cancer Institute of New Jersey and immediate past chair of the board of directors for the American Society for Radiation Oncology.
"The results of this and previous studies further support the use of hypofractionated radiation as the preferred radiation therapy for early-stage breast cancer patients," said Benjamin Smith, M.D., associate professor of radiation oncology at MD Anderson. "At MD Anderson these shorter courses have become the standard of care."
It’s possible that hypofractionated whole-breast radiation therapy isn’t used as often as it could be because ASTRO guidelines stop short of recommending the shorter schedule as a standard of care that can be used in place of traditional whole-breast radiation.
Dr. Smith currently leads an ASTRO guideline panel on whole-breast irradiation, and he hopes these and other data will support development of evidence-based treatment guidelines for early breast cancer.
If you’ve been diagnosed with early-stage breast cancer that has been removed with lumpectomy and radiation therapy will be part of your treatment plan, you may want to talk to your doctor about hypofractionated whole-breast radiation therapy and whether it makes sense for you and your unique situation. Be sure to talk about your scheduling needs and ask your doctor whether you meet the criteria for hypofractionated whole-breast radiation.
Editor’s Note: In 2018, the American Society for Radiation Oncology updated its guideline on whole-breast radiation therapy. The current guideline says that most women diagnosed with breast cancer who will have radiation therapy after lumpectomy should be treated with accelerated, also called hypofractionated, whole-breast radiation therapy as the standard of care. The preferred hypofractionated dose schedule is 40 Gray in 15 doses or 42.5 Gray in 16 doses.
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