A key question after a cancer diagnosis is whether the cancer has spread to nearby lymph nodes. Researchers at the University of Michigan Comprehensive Cancer Center have found a new non-surgical technique that can help doctors determine when breast cancer has invaded the lymph nodes, sparing some women an extra trip to the operating room.
The technique, which uses ultrasound along with a fine needle biopsy, is a reliable way of determining whether the lymph nodes are malignant, according to research results being presented Monday, Nov. 29, at the Radiological Society of North America's annual meeting in Chicago.
Traditional ways of determining cancer's spread to the axilla, or underarm, are sentinel lymph node sampling, in which the first lymph node is identified and assessed for cancerous cells, or axillary lymph node dissection, in which all the lymph nodes in the underarm are removed and examined for cancer. If the sentinel node biopsy shows cancer, then a patient needs to return to the operating room to have the lymph nodes removed.
For some women, chemotherapy may be necessary before surgery, in which case, doctors must determine whether the lymph nodes are affected before the chemotherapy begins. Rather than undergo a sentinel lymph node sampling surgery, doctors can use ultrasound-guided fine needle aspiration to confirm the cancer's spread without surgery.
"The goal of the study was to use ultrasound to pre-operatively assess the axillary lymph nodes. If we can use ultrasound to stage the axilla and identify metastatic disease, we can save some women the additional surgery," says Alexis Nees, M.D., clinical assistant professor of Radiology at the U-M Medical School. Nees will present the results at the RSNA meeting.
The technique uses ultrasound to identify the axillary lymph nodes and determine if their appearance is normal or abnormal. If they look abnormal, a small 22-gauge needle is inserted into the node to extract cells that can be evaluated for cancer. It requires only local anesthesia and involves no surgical incisions. Both sentinel lymph node sampling and axillary node dissection are full surgical procedures.
The researchers used ultrasound to examine 57 women newly diagnosed with breast cancer. If the lymph nodes appeared abnormal on the ultrasound, the researchers performed a fine needle aspiration, using ultrasound to guide the biopsy. Patients then had breast surgery and either sentinel lymph node sampling or axillary node dissection.
Pathology reports from surgery were compared to results from the ultrasound-guided fine needle aspiration. Of the women whose ultrasound showed abnormal lymph nodes, 92.8 percent had cancerous nodes at surgery. And, the researchers found, all the women with an abnormal ultrasound and a positive biopsy were found to have cancer in their lymph nodes at surgery.
"Both those numbers are extremely high," says Nees. "This tells us that axillary ultrasound combined with ultrasound guided fine needle aspiration of abnormal lymph nodes can identify some patients with cancer in their lymph nodes. These patients can proceed with chemotherapy or definitive surgery and be spared an additional surgical procedure."
Nees notes the technique is not reliable to rule out the cancer's spread; it can only confirm positive lymph nodes. Because of that, if the test comes back negative, sentinel lymph node sampling would still be necessary. The U-M Comprehensive Cancer Center offers the ultrasound and fine needle biopsy to all appropriate patients.
In addition to Nees, study authors are Mark Helvie, M.D., professor of Radiology and director of the Breast Imaging Division; Stephanie Patterson, M.D., assistant professor of Radiology; Marilyn Roubidoux, M.D., associate professor of Radiology; and Lisa Newman, M.D., associate professor of Surgery and director of the Comprehensive Cancer Center's Breast Care Center.