A test that quickly detects cancer cells in a lymph node during surgery to remove breast cancer is accurate enough to help doctors decide if lymph nodes need to be removed during the surgery.
During surgery to remove early-stage breast cancer, the lymph node closest to the cancer -- called the sentinel node -- often is removed and sent to a pathologist for evaluation. Removing just this one node is called a sentinel node dissection. Doctors remove one or more lymph nodes when removing the breast cancer to see if any cancer cells that can't be seen by the human eye are in the lymph node.
Ideally, a surgeon would know if cancer cells are in the sentinel node before the surgery to remove the breast cancer is finished. That way if any more lymph nodes need to be removed, it could be done during that one surgery. Unfortunately, accurately analyzing lymph node tissue using traditional methods takes about a week. So if cancer cells are detected in the sentinel node, a second surgery must be done.
A study evaluated a test that uses PCR (polymerase chain reaction) to determine if breast cancer cells are in the sentinel node. The test, developed by Veridex, LLC, is called GeneSearch Breast Lymph Node Assay and has been approved by the FDA.
The results of the GeneSearch test are usually available in about 35 minutes. Having lymph node analysis done this quickly would allow the surgeon to remove the breast cancer while waiting for the results of the lymph node test. If cancer is detected in the lymph node, the surgeon could then remove more lymph nodes during the same operation.
This study looked at GeneSearch test results from more than 1,100 women in the United States, the United Kingdom, and Belgium. The researchers compared the GeneSearch test results with results from traditional lymph node analysis by a pathologist. The GeneSearch test was very accurate. When the GeneSearch test result was negative, the pathologist's lymph node report also detected no cancer 96% of the time.
It's important to know that while very reliable, the GeneSearch test ISN'T a replacement for having a pathologist examine any removed lymph nodes. Still, the test could help some women avoid a second operation by determining if more lymph nodes needed to be removed during initial breast cancer surgery. The GeneSearch test also could offer a second set of reassuring results to anyone whose pathology report shows no cancer in the lymph nodes.
Stay tuned to Breastcancer.org for the latest news on research that may lead to better ways to prevent, diagnose, and treat breast cancer. And visit the Breastcancer.org Lymph Node Removal pages to learn more about the different procedures to remove lymph nodes.
Editor's note: To make sure that women have the appropriate lymph node surgery, the American Society for Clinical Oncology released guidelines on sentinel lymph node biopsy for people diagnosed with early-stage breast cancer. The guidelines say sentinel lymph node biopsy SHOULD be offered under these circumstances:
- breast cancer in which there is more than one tumor, all of which have formed separately from one another (doctors call these multicentric tumors); these types of breast cancers are rare
- DCIS treated with mastectomy
- women who have previously had breast cancer surgery or axillary lymph node surgery
- women who have been treated before with chemotherapy or another systemic treatment (treatment before surgery is called neoadjuvant treatment)
Sentinel node biopsy SHOULD NOT be offered under these circumstances:
- the cancer is 5 cm or larger or locally advanced (the cancer has spread extensively in the breast or to the nearby lymph nodes)
- the cancer is inflammatory breast cancer
- DCIS treated with lumpectomy
- the woman is pregnant
The guidelines also say:
- Women with negative sentinel node biopsies shouldn’t have axillary node surgery.
- Women with one or two positive sentinel nodes who plan to have lumpectomy plus radiation also don’t need axillary node surgery.
- Women who have one or more positive sentinel nodes and plan to have mastectomy with no radiation should be offered axillary node surgery.