Sentinel Lymph Node Biopsy is Less Invasive Procedure
By Sheila Dwyer, Body1 Staff
Reviewed by Dr. Jack Wylie
Other than skin cancer, breast cancer is the most common cancer in women. It kills more women than any other cancer aside from lung cancer. During the mid-1990s, breast cancer death rates declined among American women, probably due to heightened awareness of the disease and better methods of detection, such as mammography.
According to the National Cancer Institute’s breast cancer treatment guidelines, most women diagnosed with breast cancer have surgery to remove the cancer from the breast. During the operation, the surgeon usually removes some lymph nodes as well to test whether the cancer has metastasized.
The lymphatic system drains fluid from tissues in the body and provides the body’s defense mechanisms. Lymphocytes (white blood cells) circulate in the blood, and enter tissues at sites of infection or inflammation. They are drained by the lymphatic system, filtered at lymph nodes in the lymphatic system, and eventually returned to the bloodstream. Lymph nodes are located throughout the body, and may be palpable at times of infection or inflammation in the neck, armpits, and groin.
A recent shift in medicine has seen breast cancer patients undergo chemotherapy or surgery before a doctor stages the disease. Doctors are comfortable with this procedure because previous methods of staging breast cancer have not been completely accurate. However, new studies have shown that Sentinel Lymph Node (SLN) biopsy can stage breast cancer with a high level of reliability, which assists women’s decisions about their disease treatment options.
The SLN is the first line of defense against cancer and infections. It is so named because it is the first area within a person’s body that will receive cancer from the point where the disease originated. SLNs, which are located throughout the body, are strong predictors of a cancer patient’s outcome in terms of disease recurrence and death. They are identified when dye is injected at the site of the tumor, and the node to which the dye travels is determined to be the “sentinel” lymph node.
An SLN biopsy has two potential outcomes: node-positive and node-negative. A node-positive prognosis is grim; it indicates that the cancer has spread to the lymph nodes. A node-negative outcome means that the cancer is still localized in the breast and is therefore easier to treat.
If a woman’s results indicate that cancerous cells are present in the SLN, her chances of the cancer spreading to other organs are higher. Her oncologist may recommend an aggressive form of therapy, such as a mastectomy and radiation. A woman with a negative biopsy may undergo less invasive and less damaging treatment.
SLN biopsy makes sense for women with small breast tumors, which tend to be benign. The traditional biopsy procedure removed their lumps as well as the lymph nodes in their armpits, which sometimes results in disfigurement and limited use of the arm.
Researchers from the University of Pennsylvania and the Mayo Clinic performed a study on 103 women with breast tumors. They identified the SLN in 99 percent of the patients, with a false-negative rate of 3 percent. (False-negative rate is the rate at which the test does not identify existing cancer).
These numbers suggest that SLN biopsy should be considered a real alternative to neoadjuvant chemotherapy in terms of staging the disease. Doctors perform the biopsy in an outpatient setting, under local anesthesia, which may be less emotionally taxing for the patient. SLN biopsy is not yet a standard of care; however, it should be contemplated for breast cancer patients in the future.
References:
www.drkoop.com
www.hopkins.med.jhu.edu
www.innerbody.com
