Breast cancer is a fairly aggressive malignancy that disseminates to other parts of the body via lymph channels. Cancer cells metastasize readily to the lymph nodes located in the close proximity of malignant tissue (also known as sentinel nodes). As a result, having a better understanding of lymph node spread is important in making fundamental treatment decisions. The latest research conducted by investigators at UT Southwestern is helping to better understand the various benefits and risks of different surgical procedures that are employed in the excision of lymph nodes.
Details of the study:
It is imperative to understand that lymph nodes are an integral part of the human immune system, in that they store lymphocytes for the initiation and maintenance of a variety of immune responses. In addition, lymphatics also help in excreting toxins produced as a result of metabolism. The latest research suggests that the removal of only-affected or involved lymph nodes is a preferable approach, instead of removing all the lymph nodes in the affected region of the body, which significantly increases the risk of side-effects like lymphedema (swelling of the arm that is tense and tender, observed frequently after the removal of lymph nodes).
Roshini Rao, an associate professor of surgery at UT Southwestern, and other renowned investigators from the Harold C. Simmons Cancer Center, reviewed previously published studies in detail to determine the long-term impact of different lymph node surgeries on individual health and well-being. The research team realized that extensive surgery is not associated with a better outcome.
The biopsy of sentinel node is an important step in the conservative breast surgeries to confirm if the cancer cells are metastasizing. Axillary lymph nodes constitute 20- 30% of all lymph nodes in the underarm region, and receive lymphatic drainage from the chest, neck, and armpit. Traditionally, extensive axillary dissection is performed if the sentinel node biopsy comes out positive. However, axillary dissection is mostly associated with some short-term and long-term complications. The research team from UT Southwestern and the Harold C. Simmons Cancer Center collected, studied, and analyzed over 1000 breast cancer cases, and realized that in the absence of any visible or palpable involvement of axillary lymph nodes, the dissection or surgery does not improve the procedure-related benefits, or long-term survival.
Likewise, the study also suggested that the overall risk of lymphedema with SNL is only 5 to 7 %, risk which doubles (14%) if the axillary dissection is performed.
The 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.”
Most healthcare providers today utilize the conservative approach, which removes cancerous tissue and surrounding normal tissue, along with involved lymph nodes. Based on the sensitivity and receptor status, conservative surgery is complemented by chemotherapy and radiotherapy.
Dr. Rao highly recommended to avoid axillary surgery, which not only increases morbidity by increasing the risk of post-procedure pain, swelling, and limited range of motion, but which also is not associated with additional benefits.
The results of this study were published online in the peer-reviewed JAMA (Journal of the American Medical Association) on October 2nd.
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