WEDNESDAY, Sept. 1, 2004 (HealthDayNews) -- Older women with breast cancer may forgo the rigors of radiation after breast-conserving surgery, but radiation therapy may help younger women with early stages of the disease, new research says.
Two new studies find the age of a woman when she is diagnosed with breast cancer influences whether radiation will help when combined with other treatments, notably tamoxifen.
In women 70 years and over with early-stage breast cancer, taking tamoxifen alone and declining radiation after a lumpectomy may be a suitable treatment option, one study says.
The second paper found that in younger women (50 and over), radiation in conjunction with tamoxifen had a greater impact on reducing the risk of a local recurrence.
Both studies appear in the Sept. 2 issue of the New England Journal of Medicine.
The issue is really one of fine-tuning therapy. "The good news in breast cancer today is we are diagnosing more women with early-stage breast cancer, which is the most treatable and potentially curable," said Dr. Jay Brooks, chief of hematology/oncology at the Ochsner Clinic Foundation in New Orleans. "But how much treatment do we need to give these people?"
It is standard practice for women who have had lumpectomies to also receive radiation, which can have unpleasant side effects and can be inconvenient, particularly if one does not live near a center offering the treatment.
Tamoxifen is used against estrogen-receptor positive cancers, which represent the majority of breast cancers, especially in older women.
For the first study, researchers analyzed 636 patients aged 70 or older with early-stage, estrogen-receptor positive tumors who had already had a lumpectomy. After the surgery, the women were randomly assigned to receive tamoxifen on its own or tamoxifen plus radiation.
The only appreciable difference between the two groups was in the rate of local or regional recurrence: 1 percent in the combination group and 4 percent in the tamoxifen-only group. Still, those numbers were very low for both groups.
There were no significant differences in overall survival (87 percent for the women who received tamoxifen plus radiation and 86 percent in the tamoxifen-only group), in the spread of cancer, or in the need for an eventual mastectomy.
"The point of the study is not to say that everybody should have radiation or nobody should, but to choose based on the individual patient," said study author Dr. Kevin Hughes, co-director of the Avon Comprehensive Breast Evaluation Center at Massachusetts General Hospital in Boston. "Now we have the ability to make the choice."
That statement applies to older women. For younger women, "we completely support and recommend radiation," Hughes added.
In addition to having side effects, radiation can also be inconvenient if one does not live near a treatment center. Most times, the treatment takes several days a week for several weeks and involves driving to and from a center. "For someone 70 years old, it's a logistical issue," Brooks said.
"It takes a significant amount of time out of their life," Hughes added. "The elderly often do not have the support structure, their friends are older, or they don't drive. It's a major inconvenience."
The second study, conducted in Canada, compared tamoxifen alone with tamoxifen plus radiation in women aged 50 or older. More than 750 women with early breast cancer were randomly assigned to receive radiation plus tamoxifen or tamoxifen alone. They were followed for a median of 5.6 years.
In the tamoxifen group, 7.7 percent of the women had a local relapse vs. only 0.6 percent in the combination group. The five-year, disease-free survival rate was 84 percent in the tamoxifen group and 91 percent in the tamoxifen plus radiation group. There were no significant differences in the rates of a distance relapse.
The National Cancer Institute has more on all aspects of breast cancer.