(August 12, 2009 - Insidermedicine) Just a few tumor cells in the lymph nodes of women with breast cancer can worsen the prognosis, and these women can likely benefit from systemic treatment, according to research published in the latest issue of the New England Journal of Medicine.

Here is some information about how breast cancer spreads:

•    When breast cancer spreads beyond the breast, this is known as metastasis

•    The first place breast cancer spreads to is the axillary lymph nodes, which are under the arm

•    Breast cancer that has traveled to the lymph nodes is still considered to be relatively early disease and can often be cured with surgery, often combined with systemic treatments such as chemotherapy

Researchers from the University Medical Center in Maastricht followed three groups of breast cancer patients for an average of over five years. The first group of nearly 900 patients had no signs of cancer spread to their lymph nodes and did not receive any systemic treatment. The second group of nearly 900 patients had isolated tumor cells or early signs of cancer spread known as micrometastases in their lymph nodes and did not receive any systemic treatment. The third group of nearly 1,000 patients also had isolated tumor cells or micrometastases in their lymph nodes but did receive systemic treatment.

During the follow-up period, patients who had early signs of cancer spread to their lymph nodes who did not receive systemic treatment were more likely to die or experience a recurrence of their disease than either those without signs of cancer in their lymph nodes or those who had signs of cancer in their lymph nodes but who receive systemic therapy.

Today's research demonstrates how early signs of disease in the lymph nodes can worsen the prognosis for women with breast cancer and highlights how these women can benefit from systemic treatment.

For Insidermedicine In Depth, I'm Dr. Susan Sharma.