Breast Cancer That Spreads to Lymph Nodes Changes Form
Breast cancer cells that spread to the lymph nodes change form, a discovery that surprised Breakthrough Breast Cancer researchers in Great Britain. This new finding about the activity of breast cancers may lead to different ways to treat the disease.
After breast cancer has been diagnosed, clinicians typically perform tests to find out if the cancer cells have spread within the breast or to other parts of the body. The process by which they look for breast cancer spread is called staging. Once clinicians determine the stage of the disease, they can plan a treatment strategy.
Breast cancer can spread through the body in three ways: by invading surround normal tissue, by invading the lymph system and traveling through the lymph vessels to other places in the body, and by invading the blood and traveling through blood vessels to other parts of the body. Breast cancer cells that break away from the original tumor and travel through the lymph or blood to other parts of the body may result in the formation of another tumor. This process is called metastasis. The secondary tumor is the same type of cancer as the main tumor; thus if breast cancer cells spread to the lungs, the cancer cells in the lungs are actually breast cancer cells.
In the current study, the researchers reported that up to 40 percent of breast cancers can change form when they travel to other parts of the body. They examined 211 breast cancer tumors that had spread to the lymph nodes of the patients and found that the disease was much more difficult to treat once it had metastasized. The researchers note that this finding suggests that clinicians need to determine which type of disease a woman has in her lymph nodes in order to decide which treatment she should receive.
In addition to the surprising findings in this study, the results also may help scientists determine why some women who have had their breast cancer spread to the lymph nodes have not responded to treatment. Researchers hope that with additional testing they will be able to find treatment regimens that are more effective for women with breast cancer.
BBC News November 4, 2009
National Cancer Institute