Two studies have found that women diagnosed with early-stage breast cancer treated with a shorter whole-breast radiation schedule after lumpectomy have fewer side effects and better quality of life than women treated with the longer, traditional radiation schedule.
The studies were published online on Aug. 6, 2015 by JAMA Oncology. Read the abstracts of:
- "Acute and Short-Term Toxic Effects of Conventionally Fractionated vs Hypofractionated Whole-Breast Irradiation: A Randomized Clinical Trial"
- "Differences in the Acute Toxic Effects of Breast Radiotherapy by Fractionation Schedule: Comparative Analysis of Physician-Assessed and Patient-Reported Outcomes in a Large Multicenter Cohort"
After lumpectomy to remove early-stage breast cancer, radiation therapy often is used to reduce the risk of recurrence (the cancer coming back). 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 new radiation therapy schedule that involves fewer treatments with higher doses of radiation at each treatment, but the same total radiation dose. So the new 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. But since the studies the ASTRO experts looked at to write the guidelines included smaller numbers of younger women, the experts weren’t comfortable including younger women in the guidelines.
The two JAMA Oncology studies were different types. One was a randomized study, which means the researchers randomly assigned women to a treatment group. The other study was an observational study, which means the researchers looked at the records of women after treatment was done to see any differences in outcomes.
In the randomized study, the researchers randomly assigned 287 women diagnosed with DCIS, stage I, or stage II breast cancer who had had lumpectomy to one of two radiation schedules:
- 149 women received conventional whole-breast radiation (50 Gray over a period of 5 weeks, plus a boost dose)
- 138 women received hypofractionated whole-breast radiation (42.56 Gray over a period of 3 weeks, plus a boost dose)
The women were all 40 years of age or older and 76% (217 women) were overweight or obese.
The women on the hypofractionated radiation schedule had fewer side effects than the women on the conventional radiation schedule:
- 36% of the women in the hypofractionated group had skin inflammation compared to 69% of the women in the conventional group
- 54% of the hypofractionated group had itchy skin compared to 81% of the conventional group
- 55% of the hypofractionated group had breast pain compared to 74% of the conventional group
- 9% of the hypofractionated group had skin darkening compared to 20% of the conventional group
- 9% of the hypofractionated group reported fatigue compared to 17% of the conventional group
Overall, 47% of the hypofractionated group had one or more side effects compared to 78% of the conventional group.
All these differences were statistically significant, which means they’re probably because of the difference in treatment and not just due to chance.
In the observational study, the researchers looked at the records of 2,309 women diagnosed with early-stage breast cancer who had lumpectomy and then whole-breast radiation after surgery from October 2011 to June 2014:
- 578 women received hypofractionated radiation
- 1,731 women received conventional radiation
The researchers looked to see how many side effects were reported by both the women and their doctors.
As in the randomized study, there were fewer side effects in women treated with hypofractionated radiation:
- 6.6% of women in the hypofractionated group had weeping, blistered skin compared to 28.5% of women in the conventional group
- 27.4% of the hypofractionated group had skin irritation compared to 62.6% of the conventional group
- 24.2% of the hypofractionated group had moderate to severe pain compared to 41.1% of the conventional group
- 15.7% of the hypofractionated group had burning or stinging skin compared to 38.7% of the conventional group
- 18.9% of the hypofractionated group reported fatigue compared to 29.7% of the conventional group
Again, these differences were all statistically significant.
"These findings should be communicated to patients as part of shared decision making regarding election of radiotherapy regimen and are relevant to the ongoing discussion regarding the most appropriate standard of care for [whole-breast radiation] dose fractionation," wrote the researchers who did the randomized study.
Earlier studies have shown that hypofractionated whole-breast radiation after lumpectomy offers the same recurrence risk reduction benefits as conventional whole-breast radiation. The two studies reviewed here show that hypofractionated whole-breast radiation also causes fewer side effects than conventional whole-breast radiation.
Despite these results and ASTRO recommendations, fewer than 33% of women eligible for hypofractionated radiation receive it. When asked why they have stuck with the conventional whole-breast radiation schedule, radiation specialists have said they are concerned about side effects when compressing the same radiation dose into a 3- to 5-week schedule. It’s possible that as the results of these two studies are distributed and discussed, more specialists may use hypofractionated radiation.
Another reason that hypofractionated whole-breast radiation therapy isn’t used as often as it could be may be because the 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. This lack of a clear recommendation may be contributing to the shorter schedule being underused.
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. It’s also a good idea to talk to your doctor about skin reactions to radiation -- together you can develop a plan to ease any skin irritation that happens during and after radiation therapy.