By: Elaine Gottlieb for Uterus1
A new breast cancer diagnostic test promises to make treatment easier by reducing surgeries and lessening patient anxiety. Approved by the Food and Drug Administration (FDA) in July, the laboratory test – known as the GeneSearch Breast Lymph Node Assay – detects genetic markers in lymph nodes that have been shown to be an effective predictor of whether the cancer has spread.
|Learn more about the current status of breast cancer treatment and research and options for detecting cancer in lymph nodes at the National Cancer Institute.|
Learn about the GeneSearch Breast Lymph Node Assay, including how it is administered and who is eligible to take it.
If you are diagnosed with breast cancer, be sure your healthcare provider thoroughly discusses your condition and which diagnostic tests and treatment processes are appropriate for you. Don’t be afraid to voice concerns or to seek a second opinion.
Detecting the presence or absence of breast cancer cells in underarm lymph nodes, which help protect the body against infection, is a standard part of the treatment process and helps to determine the appropriate course of therapy.
Currently, during a lumpectomy or mastectomy, surgeons commonly remove the “sentinel” lymph node for microscopic examination. Since the sentinel node is the first lymph node to filter fluid from the breast, it is where breast cancer cells are likely to spread (metastasize) first. A sentinel node biopsy can take one to three days to return results, which creates additional stress for patients and, if cancer is present, may mean that they must undergo a second surgery to remove additional lymph nodes.
On the other hand, the GeneSearch Assay can be done in as little as 40 minutes. The test “offers a new approach to sentinel node testing,” said Daniel Schultz, M.D., director of the FDA’s Center for Devices and Radiological Health, in a statement. “Results of this rapid test are available while patients are on the operating table, providing a way for some women to avoid a second operation.”
Manufactured by Johnson & Johnson subsidiary Veridex, the gene-based technology of the GeneSearch assay can analyze 50 percent of the sentinel node compared to five percent in microscopic examinations.
In clinical trials, the test showed strong agreement with the results from extensive microscopic examination of the lymph nodes of 416 patients. It accurately predicted that breast cancer had spread nearly 88 percent of the time in women with metastasis. Patients who did not have metastasis were identified accurately 94 percent of the time.
If follow-up studies confirm its higher level of accuracy, the GeneSearch could potentially prevent the need for second surgeries for as many as 5,200 additional breast cancer patients in the United States each year.
However, while the test gave fewer false-negative results, it gave slightly more false-positive results. A false-negative test result, which indicates that the cancer has spread but the test didn’t detect it, while a false-positive result, indicating metastasis where there is none, may result in unneeded surgery to remove lymph nodes, a procedure whose side effects include lymphedema (swelling due to fluid build-up following lymph node removal).
The test has been commercially available in the European Union since November 2006 and has been adopted by the Institut Jules Bordet in Belgium, among other healthcare facilities.