Two new studies found a shorter course of whole breast radiation therapy at higher doses produced less toxic effects than a longer course at lower doses.
Breast cancer is the most common cancer among women in the US, after skin cancer. It is estimated that more than 230,000 American women will be diagnosed with breast cancer this year, and more than 40,000 will die from the disease.
Whole breast radiation therapy is often recommended for women diagnosed with early-stage breast cancer who have undergone breast-conserving surgery in order to reduce the risk of cancer recurrence.
In the US, conventionally fractioned whole breast irradiation (CF-WBI) is the most common type of whole breast radiation administered to breast cancer patients, which involves smaller radiation doses over a longer period of time.
Another treatment option for patients is the administration of higher radiation doses over shorter time periods, known as hypofractionated whole breast irradiation (HF-WBI). Previous research has shown this treatment is just as effective as CF-WBI.
"Randomized studies in the United Kingdom and Canada have shown equal rates of recurrence in both groups, as well as equal survival," says Dr. Simona Shaitelman, of the MD Anderson Cancer Center at the University of Texas - co-author of one of the new studies, noting that despite such findings, the radiation oncology community in the US has been slow to adopt HF-WBI.
"So the question is," adds Dr. Shaitelman, "with modern technology, and knowing that the survival and recurrence outcomes are equal, can we offer patients a better option?"
HF-WBI patients better able to meet family needs after 6 months
To find out, Dr. Shaitelman and colleagues analyzed data of 287 women aged 40 and older who had been diagnosed with early-stage breast cancer and had undergone breast-conserving surgery.
Of these patients, 149 were randomized to receive CF-WBI (at a dose of 50 Gy/25 fractions plus a "boost" dose) and 138 received HF-WBI (at a dose of 42.56 Gy/16 fractions plus a boost).
For a minimum of 6 months, the team looked at the toxic effects of each treatment and how they impacted patients' short- and long-term quality of life.
The team found that during treatment, patients who received HF-WBI experienced much lower incidence of acute dermatitis, severe itching, breast pain, hyperpigmentation and fatigue than those who received CF-WBI.
While both groups experienced similar toxic side effects 6 months after treatment initiation, patients who received HF-WBI reported less fatigue and more energy than CF-WBI patients.
What is more, HF-WBI patients reported less trouble meeting family needs after 6 months - a finding Dr. Shaitelman says is particularly important. "This is a major priority for women undergoing breast cancer radiation," she notes. "Most are busy working mothers, working inside or outside the home, and are juggling a number of priorities. It's paramount that we address this need."
The team believes their findings should be communicated to patients electing whole-breast radiation therapy for breast cancer and incorporated as part of the decision-making process. Study co-author Dr. Benjamin Smith adds:
"This study fills in a missing piece in the literature. No longer do I regard the shorter course of treatment as just an option for patients, but rather the preferred starting point for discussion with patients if they need whole breast radiation."
HF-WBI 'should be considered for majority of patients with early-stage breast cancer'
Another study conducted by Dr. Reshma Jagsi, of the University of Michigan-Ann Arbor, and colleagues assessed the toxic effects of both HF-WBI and CF-WBI during 1 week of treatment.
The team analyzed data of 2,309 women who received whole breast radiation therapy after undergoing breast-conserving surgery. Of these patients, 570 received HF-WBI and 1,731 received CF-WBI.
- Around 1 in 8 women in the US will develop breast cancer in their lifetime
- Breast cancer is the second leading cause of cancer death among women in the US - the first being lung cancer
- There are around 2.8 million survivors of breast cancer in the US.
The researchers found that patients who underwent CF-WBI had greater incidence of skin reactions, breast pain and fatigue than those who received HF-WBI - echoing the study findings from Dr. Shaitelman and colleagues. CF-WBI patients also had increased burning/stinging, swelling and hurting, according to the results.
However, after 6 months of follow-up, Dr. Jagsi and colleagues identified no differences in toxic effects between each treatment group.
The team says their findings indicate a "simple adjustment to dosing schedules" with HF-WBI may offer a less costly, convenient treatment for patients with early-stage breast cancer.
In an editorial linked to both studies, Dr. Shyam K. Tanguturi, of the Harvard Radiation Oncology Program, and Dr. Jennifer R. Bellon, of the Dana-Farber Cancer Institute - both in Boston, MA - say the studies are "highly complementary."
They explain that the study by Dr. Jagsi et al is a "real-world, community-based study" with a large cohort, though its nonrandomized design makes it subject to confounding. They say the study from Dr. Shaitelman and colleagues, however, is a more "rigorous, randomized study design," but is limited by lower patient numbers.
Together, Dr. Tanguturi and Dr. Bellon say the studies illustrate much lower rates of patient- and physician-reported early toxicities with HF-WBI compared with CF-WBI.
"With comparable tumor control, lower costs and reduced morbidity, hypofractionation should be strongly considered for the majority of patients with early-stage disease," they conclude.
Last week, Medical News Today reported on a study in which researchers reveal the discovery of a potential drug target for triple-negative breast cancer.