(RxWiki News) One of the first places breast cancer spreads is to the lymph nodes closest to the tumor. Learning where the cancer has spread is important for making treatment decisions. A new review looked at the risks and benefits of various surgical means of removing lymph nodes.
Lymph nodes are part of the immune system. They get rid of waste products and store white blood cells called lymphocytes.
After reviewing a number of different studies, researchers have discovered that, in most cases, removing fewer lymph nodes may be preferable to removing all lymph nodes in breast cancer patients.
The researchers found that a conservative approach did not affect survival and lowered the risk of painful arm swelling known as lymphedema.
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Roshni Rao, MD, associate professor of surgery at UT Southwestern, and other investigators from the Harold C. Simmons Cancer Center analyzed 17 studies on the outcomes of women who had various types of lymph node surgery.
The lymph nodes closest to the tumor are called the sentinel lymph nodes. To learn if cancer cells have spread, surgeons perform a sentinel lymph node biopsy that looks at the node(s) closest to the tumor.
Women with early breast cancer typically have what’s known as breast-conserving therapy. This involves removing the tumor and nearby tissue. Then radiation is performed to kill any remaining cancer cells.
During the surgery, a sentinel lymph node (SLN) biopsy is performed to see if the cancer has spread.
A positive sentinel lymph node biopsy means that cancer has appeared in this first node or other nearby lymph nodes and shows that the tumor has spread (metastasized) beyond its original site.
Axillary lymph nodes are found at the edge of the chest muscles, armpit and lower neck. An axillary lymph node dissection removes all 20-30 nodes in the armpit.
It has been the standard of care to perform an axillary lymph node dissection if the SLN biopsy was positive.
This study was designed to review the risks and benefits of sentinel lymph node biopsy compared to axillary node dissection.
The researchers looked at studies involving more than 1,000 cases of breast cancer.
The review of these studies showed that axillary node dissection in patients with no palpable (can be seen or felt) lymph nodes offered no survival benefit.
The procedure was linked with a 1 to 3 percent reduction in recurrence (return) of lymph node metastasis.
Axillary lymph node dissections also increased the risk of lymphedema by 14 percent compared to the 5 to 7 percent risk of lymphedema in patients who had an SLN biopsy.
According to Dr. Rao, who is a breast surgeon, axillary surgery should be avoided if possible because it can cause shoulder and arm problems that can include severe pain or numbness and reduced range of motion.
The authors of this study concluded, “Available evidence suggests that axillary node dissection is associated with more harm than benefit in women undergoing breast-conserving therapy who do not have palpable, suspicious lymph nodes, who have tumors 3.0 cm or smaller, and who have 3 or fewer positive nodes on sentinel node biopsy.”
This study was published October 2 in JAMA (Journal of the American Medical Association).
No outside funding source was named. One of the authors has a financial relationship with a consulting group, and one author reported receiving fees from two pharmaceutical companies.