Benefit in Radiation After Breast Cancer Surgery

Radiotherapy after surgery for breast cancer significantly reduces the risk of relapse in the breast or to other parts of the mortal body for 10 or 15 years, say researchers.

The new results show that radiation prevents recurrence more and save more lives than generally recognized, said Sarah C. Darby, professor of medical statistics at Oxford University and author of the report.

These reassuring results were reported Wednesday in the British journal The Lancet, is based on an analysis of 17 studies involving 10 801 women in Europe, Canada and the United States. All tumors were small enough to work with breast-conserving surgery, a lumpectomy or other methods to the tumor, without removing the entire breast funds handled. The women were randomly assigned to receive radiotherapy or not, and followed for a median of 9.5 years. Some were observed during 20 years.

Total radiation reduces the risk of relapse during the first 10 years after surgery to 19.3 percent from 35 percent and reduces the risk of death from breast cancer by 25 percent to 21.4, 2 percent in the first 15 years.

"It is only relatively recently it was discovered that the radiation has a significant effect on mortality," Dr. Darby said, explaining that this positive result does not recognize at first because it takes five years to see.

"These data confirm that the relapse rate was reduced in the first ten years," he said. "It was not so clear. It is not just for one year or the first, but significantly reduced during an entire decade."

A researcher said no part of the study, Dr. Thomas A. Buchholz, director of radiation oncology at the University of Texas MD Anderson Cancer Center: "The results are very important group of Oxford researchers have developed breast cancer is the most important, it allowed data to to receive.. almost every single randomized, controlled trial, both in the U.S. and Europe. Power is, you can combine the data for very large samples and to answer basic questions. "

Earlier research by the Oxford group also found that radiation may prevent recurrence and increase survival, said Dr. Buchholz.

"Now, to confirm, with a long-term follow-up, the importance of radiation, not only to increase to prevent a recurrence, but the chances of a cure," he said. "It is part of the most important data that we have about the treatment of breast cancer."

The theory behind giving radiotherapy after surgery for breast cancer no stray cancer cells that have been left to kill, and to prevent them is that the development of another tumor or spread to vital organs.

But studies are needed to determine if the theory held, mainly because the radiation has side effects such as skin burns and exhaustion.

Some researchers have questioned whether the radiation was necessary, arguing that even if the cancer has come back in the breast, surgery would get rid of yet, and that the return does not necessarily mean the disease is spreading. The new findings challenge that thinking.

"If someone has a local recurrence, yes, you can in the management, but before that some of the arrears, the cancer has spread," said Dr. Darby.

Some researchers have thought that if a tumor tends to spread, would have done even before the first surgery, so that the radiation would be too late to stop it - another idea dissipated by new discoveries.

The analysis by Dr. Darby noted that after 15 years to avoid all four repeats, death was averted.

The majority of women in the study - 7287 - had no cancer in the lymph nodes, which are usually a good sign. In 1050, the other, there were positive lymph nodes, and in 2464 there was no information about the node. Some women taking tamoxifen, a drug may block the hormone that women whose tumors are fueled by estrogen. And many women with cancer lymph nodes also had chemotherapy. Regardless of what other treatments they have received, all women received radiation.

For women with lymph node clear 10 years, reducing the radiation risk of relapse by half, to 15.6 percent from 31 percent and the risk of death from 15 years to 17.2 percent from 20.5 percent. In women with node-patients, the radiation reduces the relapse rate by 42.5 percent from 63.7 percent and reduce the risk of death to 42.8 percent from 51.3 percent.

Previous studies have shown that breast cancer radiation can damage the heart and increase the risk of a woman dying of heart disease. But the techniques have improved in recent years to prevent heart and lung radiation, and the study by Dr. Darby has no significant differences between women who received radiation is detected or not, when it comes to mortality due to other diseases as breast cancer does.