WebMD Health News
Reviewed By Louise Chang, MD
Sept. 22, 2008 -- A breast cancer treatment protocol that involves just one week of radiation instead of six or seven looked highly promising in a four-year follow-up study, researchers say.
If proven as effective as conventional radiation, the procedure, known as accelerated partial breast irradiation (APBI), could make breast conservation a more attractive option for early stage patients who now choose mastectomy to avoid radiation.
Only about half of women who are good candidates for breast-conserving surgery have it, and it is clear that lack of access to radiation facilities and length of radiation treatment are contributing factors.
"Some women live hundreds of miles from a radiation center or they feel they can't take seven weeks off from their jobs," Dallas breast surgeon Peter D. Beitsch, MD, tells WebMD. "These women often end up having mastectomies."
Accelerated Radiation Controversial
Approved by the FDA in 2002, the accelerated radiation protocol evaluated in the study is not widely used for the treatment of breast cancer.
Instead of irradiating the whole breast, the treatment focuses radiation at the site of the removed tumor using a special single balloon catheter that delivers the radiation through tiny radioactive seeds.
"It is fair to say that the technique is controversial in the radiation and oncology community, in part because we haven't had good long-term follow-up data on the patients who have had it," Beitsch says.
In an effort to address this concern, Beitsch and colleagues are following patients who have had the partial breast irradiation.
They reported on outcomes among the first 400 women in their registry Monday at the annual meeting of the American Society for Therapeutic Radiology and Oncology in Boston.
About four years after treatment, a little more than 2% of these early-stage patients who had breast-conserving surgery followed by the weeklong radiation regimen had recurrences of their cancer.
This recurrence rate is similar to that seen with more conventional whole-breast radiation, Beitsch says.
"Obviously, we will know more when we have been following these patients longer, but the early follow-up data are encouraging," he says.
Radiologist Phillip M. Devlin, MD, of Brigham and Women's Hospital, agrees.
Devlin is chief of the division of brachytherapy at Brigham and Women's and an assistant professor of radiation oncology at Harvard Medical School.
"These are preliminary results, but they suggest that outcomes for carefully selected patients are as good as those with full breast radiation," he says.
Careful Selection Is Key
Not all women with early-stage breast cancer are good candidates for the partial breast irradiation protocol.
It is not considered appropriate for women who are younger than 45, have tumors that are 3 cm or larger, have node-positive tumors, or who show evidence of cancer cells at the margins of the tumor tissue removed during surgery.
Lobular tumors -- those that start in the milk-producing glands instead of the milk ducts -- should also be treated with conventional radiation, researchers say.
Even with these restrictions, Beitsch says the vast majority of patients with early-stage breast cancers could have the accelerated radiation.
And Devlin says it is high time that more radiologists offer the protocol to their patients.
"The great shame of American medicine is that despite the data that this seems to be a very safe treatment, today -- in 2008 -- the majority of women who are eligible for breast-conservation surgery end up having mastectomies because of access to care," he says.
SOURCES: American Society for Therapeutic Radiology and Oncology annual meeting, Boston, Sept. 21-25, 2008. Peter D. Beitsch, MD, co-principal investigator, American Society of Breast Surgeons MammoSite registry. Phillip M. Devlin, MD, chief, division of brachytherapy, Brigham and Women's Hospital, Boston; assistant professor of radiation oncology, Harvard Medical School.
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