Women who receive radiation therapy after breast-conserving surgery (lumpectomy) increase their chances of surviving breast cancer, according to the results of a new study. Past studies have shown that radiation can reduce the risk that breast cancer will return after breast-conserving surgery, but the current study is the first to definitively show that radiation may actually reduce the risk of death. The researchers say their results should help doctors and patients decide whether radiation is an appropriate treatment option. Radiation therapy (or radiotherapy) uses high-energy rays to stop cancer cells from growing and dividing. The treatment is often used to destroy any remaining breast cancer cells in the breast, chest wall, or underarm area after breast cancer surgery. In some cases, radiation therapy is used to try to shrink the size of a tumor prior to surgery. To determine whether radiation therapy can reduce the risk of dying from breast cancer, Sarah Darby of Oxford University in England and an international team of researchers analyzed medical data from 40,000 patients with early-stage breast cancer who underwent various types of surgery. The analysis showed that the 15-year risk of dying from breast cancer decreased by 5% among women who underwent radiation therapy after breast-conserving surgery. The near-term results were even more promising among women who received radiation therapy. Women who had radiation therapy after breast-conserving surgery reduced their chances of dying from breast cancer after five years from 26% to only 7%. The study also found that radiation therapy decreases the risk of death among women who have their breasts removed (mastectomy), if their cancer has spread to the underarm lymph nodes. "This study provides the first really definite evidence that, for women who've had breast-conserving surgery and for women whose cancer has spread to the armpit, radiotherapy reduces the long-term risk of dying from the disease," said Sir Richard Peto of the University of Oxford, in a Cancer Research UK news release. Cancer Research UK and Britain's Medical Research Council funded the study. In the United States, radiation therapy is recommended by most doctors to treat early-stage breast cancer patients who are undergo breast-conserving surgery. However, some women are reluctant to receive radiation therapy because of the fear of side effects. The most common side effects of radiation therapy include fatigue, loss of white blood cells, swelling, a feeling of heaviness in the breast, a sunburn-type appearance of the breast skin, and loss of appetite. Most side effects are temporary and usually disappear after six to 12 months. In some cases, more serious, permanent side effects can occur, including permanent arm swelling (lymphedema), permanent limitation of movement, or in rare cases, life-threatening events such as a heart attack. While the improvement may appear small, the researchers say their study shows that the risk of dying is clearly reduced if radiation therapy is administered after breast-conserving surgery. "The findings from this study will help doctors and patients with the information they need to weigh up the side effects and benefits when discussing the most appropriate treatment options," said Dr. Lesley Walker, Director of Science Information, in the Cancer Research UK news release. It should be noted that the study did find one subset of early-breast cancer patients for which radiation therapy did not appear to provide a substantial benefit. According to the researchers, women treated with mastectomies whose cancers have not spread to the underarm lymph nodes do not need radiation. In the study, the benefit of radiation was outweighed by the potentially serious side effects such as permanent swelling or limited movement of the arm. Breast cancer patients should discuss the possibility of radiation therapy with their doctors. Radiation therapy may or may not be appropriate, given the individual medical situation.
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