The research shows that when patients with breast cancer received radiation therapy to their lymph nodes – not just the area of the breast where cancer occurred – cancer did not recur in the original site or spread to other parts of the body. Interestingly, the results were the same regardless of whether the cancer had spread to the lymph nodes.
A group of Canadian researchers at the Juravinski Cancer Center at Hamilton Health Sciences led a study of more than 1,800 women. In a separate project, researchers at Radboud University Medical Center in the Netherlands studied more than 4,000 European women. Results were published online Wednesday in the New England Journal of Medicine.
All of the participants had undergone a lumpectomy or a mastectomy. The studies then compared recurrence and survival data between a group of women who received radiation to their lymph nodes against those who did not.
Our bodies have a network of lymph vessels and lymph nodes that is part of the body’s immune system. Your lymph system collects fluid, waste material, and other things such as viruses and bacteria that are in the body tissues outside the bloodstream.
Breast cancer can spread to the lymph nodes that are under your arms and near your collarbone. This is a regional spread of the disease and is not metastatic cancer, which is when cancer spreads to other parts of your body. Metastatic cancer is incurable.
Both studies showed radiation to the lymph nodes –regardless of whether cancer had spread there — reduced the rate of cancer recurrence at the original site, as well as metastatic spread.
The role of radiation therapy
Radiation therapy uses high-energy x-rays that kill cancer cells while minimizing damage to healthy cells. When used in breast cancer treatment, radiation typically targets the area of the breast affected by cancer. Radiation also may be beamed at lymph nodes if cancer cells have spread there as well.
In the two studies, radiation to the lymph nodes did not increase the percentage of people who were still alive 10 years after they started treatment for cancer. But it did reduce the rate of breast-cancer recurrence and spread.
“By treating a larger area to include the lymph nodes, it not only prevented recurrences from happening locally in the area of the breast and the lymph nodes but also prevented breast cancer from showing up elsewhere in the body,” says breast cancer specialist Rahul Tendulkar, MD.
The studies may help doctors better determine which breast cancer patients are the best candidates for more comprehensive treatments, Dr. Tendulkar says.
These studies add to the progress that continues to be made toward more personalized treatments for women with breast cancer, he says.
“There are many different varieties of breast cancer,” Dr. Tendulkar says. “A number of different factors must be taken into consideration when coming up with a treatment plan for each individual.”