FRIDAY, Dec. 16, 2005 (HealthDay News) -- Women who receive radiation after a lumpectomy for breast cancer have better long-term survival odds than women who forego radiation after their surgery, a new British study finds.
"It is now clear that radiotherapy saves lives in women who have had breast-conserving surgery and in women whose cancer has substantial spread to the armpit, even if they have already had a mastectomy," said Sarah Darby, a professor of medical statistics at the University of Oxford's Clinical Trial Service Unit in the United Kingdom. "This should encourage women who are offered radiotherapy to go ahead and have the treatment. It may also encourage doctors to consider more women for radiotherapy than they have done in the past."
Darby is co-author of a study detailing the findings, which appear in the Dec. 17 issue of The Lancet.
Lumpectomy, or breast-conserving surgery, removes the tumor plus a margin of normal tissue around it. Unfortunately, the procedure sometimes leaves some rogue cancer cells behind, which can result in a recurrence. Previous research had shown that administering radiation after surgery reduces the risk of a local recurrence.
"It's important to treat breast cancer thoroughly from the beginning," noted Dr. Jay Brooks, chairman of hematology/oncology at the Ochsner Clinic Foundation in Baton Rouge, La. "If not, it increases the risk of local failure and, if that happens, it puts a woman at high risk of that cancer becoming metastatic."
It had been unclear, however, if longer term, 15-year survival rates were affected by doing radiation soon after surgery.
Generally, a lumpectomy can be performed if the cancer has not spread widely. Another study found, however, that even women with the option of a lumpectomy often choose a mastectomy (removal of the entire breast) out of fear that the cancer will return -- despite the fact that the survival odds are the same between the two procedures.
In recent years, medical practice guidelines have recommended that a lumpectomy should be performed, if possible, in lieu of a mastectomy. But there has been concern among health experts that the mastectomy rate has remained high.
The Lancet study revisited information on 42,000 women who had participated in 78 randomized trials around the world comparing different breast cancer treatments. The analysis was carried out by the Early Breast Cancer Trialists' Collaborative Group.
The risks of having a local recurrence were 7 percent for women who took radiation vs. 26 percent for women who did not. All the women had first had breast-conserving surgery.
At the 15-year mark, 30.5 percent of women who had had radiation died vs. 35.9 percent of women who had not undergone radiation.
The authors figured that, on average, for every four local recurrences avoided by radiation therapy, one breast cancer death is avoided.
In addition, radiation also produced a reduction in the risk of a local recurrence and improved long-term survival odds in women whose cancer had spread to the lymph nodes in the armpit. The five-year risk of a local recurrence, after mastectomy and surgery to the armpit, were 6 percent with radiation vs. 23 percent without. The 15-year death rate was 54.7 percent with radiation and 60.1 percent without.
According to the authors, it probably makes little sense to offer radiation to women who have already been cancer-free for several years. It might be worth considering, however, in women who had lumpectomy for breast cancer or mastectomy for cancer that had spread to the lymph nodes within the past year or so.
In the meantime, Darby added, researchers need to turn their attention to see whether or not radiation is worthwhile in women whose cancer has only just started spreading to the armpit.
For some women, however, the current numbers may offer some clarity. "The findings fit in well with previous research, and provide definite answers where previously there was uncertainty," Darby said.
The Ochsner Clinic's Brooks stressed that radiation is not the only advance for women with breast cancer. Hormone therapy, such as tamoxifen or aromatase inhibitors, are also radically decreasing risk, he said.
To learn more about radiation after lumpectomies, visit the American Cancer Society.