Women with early-stage breast cancer and one or two positive sentinel lymph nodes who undergo sentinel lymph node dissection fare as well as those who have the more aggressive procedure, axillary lymph node dissection, according to a study.
In addition, the majority of women with small tumors could avoid ALND altogether if they elect to undergo breast-conserving therapy rather than mastectomy, researchers reported in the January issue of the Journal of the American College of Surgeons.
In the past, when staging and removing invasive breast cancer, surgeons relied on ALND, which removes about 10 or more lymph nodes in the under-arm area. In recent years, SLND has grown in use as a standard of care for assessing the status of the lymph nodes. SLND removes only the one or two lymph nodes that first receive lymphatic drainage from the primary tumor, and is preferred by many women who seek to avoid ALND and have a less invasive operation. SLND reduces the risk of surgical complications such as arm swelling, numbness and range-of-motion problems.
“I think its really evident now that many patients we are seeing are very early-stage, that the sentinel node procedure is picking up very small volumes of disease when the tumor has spread to the lymph nodes,” Kelly K. Hunt, MD, FACS, a study coauthor and the Hamill Foundation Distinguished Professor of Surgery at the University of Texas MD Anderson Cancer Center in Houston, said in a news release.
“Sentinel lymph node surgery is less invasive, provides accurate staging and improves the quality of life for cancer patients.”
The American College of Surgeons Oncology Group previously conducted a groundbreaking study referred to as the Z0011 trial in which the researchers concluded that the standard practice of ALND after lumpectomy and positive sentinel node analysis was not mandatory for all women with small tumors.
In reporting their results in February 2011, the researchers found that women with stage I or II breast cancer who had only one or two cancerous lymph nodes removed were as likely to be alive and free of cancer after five years as were women who had ALND, possibly because adjuvant therapies may kill cancer cells in the axillary lymph nodes.
But whether eliminating ALND could affect a substantial portion of the breast cancer population remained unclear. The latest study involved 861 women treated at The University of Texas MD Anderson Cancer Center between 1994 and 2009 who met the Z0011 trial criteria: stage I or II breast cancer and one or two positive sentinel nodes. Researchers compared overall survival and disease-free survival rates for ALND versus SLND alone in women undergoing breast-conservation therapy or total mastectomy.
Of the 861 patients, 188 (21.8%) underwent SLND alone. Of 488 patients (56.7%) who underwent breast-conservation therapy, 125 (25.6%) had SLND alone. Of 412 patients who underwent total mastectomy, 67 (16.3%) had SLND alone.
After adjusting for tumor stage, the research team found no significant differences in survival between women undergoing SLND alone or ALND in both populations. Further, after examining their breast cancer patient population with Z0011 criteria, they estimated that up to 75% of their patients could avoid ALND if they undergo breast conservation therapy.
“Now armed with data from the Z0011 trial, we can say if the sentinel lymph node is positive and the disease is limited to one or two sentinel nodes, you can have breast-conservation therapy and avoid ALND, because we know that your survival will not be impacted by leaving the rest of the nodes intact,” Hunt said.
“With our current study, we are not saying that ALND should be eliminated, but we should use it more wisely so that all these other women, a huge percentage of patients we are treating, do not have to suffer the long-term debilitating consequences of that aggressive procedure.”
The study is available at www.journalacs.org/article/S1072-7515%2812%2901198-2/fulltext.