In treating breast cancer, a less invasive technique of removing and testing lymph nodes close to the tumor has proved to be as effective as the traditional method of removing dozens of lymph nodes under the arm, according to a new study.
To test whether cancer has spread, surgeons do a sentinel node resection to remove and test one to three lymph nodes nearest to the tumor. If negative, they do not proceed to the more invasive axillary dissection involving the removal of multiple nodes, which may cause pain, nerve damage, tingling, lack of sensation, difficulty moving the arm and shoulder, and lymphedema -- the potentially painful and even debilitating swelling of the arm.
"If it is not healthy tissue, then you can decide to remove it. If you have healthy tissue, leave it alone," said Thomas B. Julian, associate director of Allegheny General Hospital's Breast Cancer Center. He was a principal investigator along with Norman Wolmark, an AGH surgical oncologist and chairman of the National Surgical Adjuvant Breast and Bowel Project, which conducted the study.
Julian presented the results during the annual American Society of Clinical Oncology meeting, noting the trial confirms that the less invasive sentinel node resection is safe and effective. "Sentinel node resection is clearly the standard of care for these women," he stated in a news release.
The 10-year follow-up of the large Phase III trial, which compared the methods' impact on breast cancer survival and recurrence, showed no significant difference in overall survival or disease-free survival, Julian said.
The sentinel node procedure already is being used in larger treatment centers, said Kathy Purcell, chief executive officer of the Susan G. Komen Foundation's Pittsburgh affiliate. Now all medical centers can feel comfortable using the less invasive procedure that generally causes fewer side effects, she said.
The study involved 5,611 women with breast cancer from across the United States and Canada. They were randomly assigned to one of two groups: Both the sentinel node and underarm axillary node surgeries or the sentinel node surgery alone, with axillary node removal occurring only if the sentinel nodes were found to be positive for cancer.
The lymphatic system drains cellular waste, with the nodes filtering bacteria, cancer and other waste to help prevent it from reaching the blood. But cancerous cells can collect and grow inside the node and break free to spread to other tissue and the blood. Cancer in the breast tumor also can gain access to the blood and metastasize, Julian said.