Sentinel Lymph Node Dissection

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Sentinel lymph node dissection is one of the most talked about new surgical techniques in breast cancer. This is an alternative to axillary lymph node dissection (removal of the entire nodal tissue), and many women believe that it can spare them more invasive surgery and side effects. However, the sentinel node procedure is not appropriate for everyone.

Sentinel lymph node is the very first node that is reached by lymph fluid from the site of a breast cancer and thus it is the first lymph node to which cancer (if present) is likely to spread from the primary site of malignancy. When cancer spreads, the malignant cells may appear first in the sentinel node before spreading to other lymph nodes which are more distant from the primary tumour. 

Sentinel lymph node dissection is a surgery to find and remove the sentinel lymph node which as mentioned above is most likely to contain malignant cells if cancer is present. The idea behind this surgery is to remove and analyze the one node that is most likely to have malignant cells in it instead of removing ten or more lymph nodes and investigate all of them for cancer. If the sentinel node is free of cancer cells, it is most probable that the other lymph nodes have not been affected. In reality, the surgeon usually removes a cluster of two or three lymphatic nodes - including the sentinel node and one or two closest to it. This strategic removal of just one or a few key underarm nodes can accurately assess overall lymph node status in women with early breast cancer and who have lymph nodes that do not feel abnormal before the surgery. It may help to minimize the patient's trauma by providing treatment options based on specific lymph node findings. If the findings are positive the patient usually has to undergo a radical axillary node dissection (surgery to remove more lymph nodes in the armpit area). In the case of axillary dissection, 5-10 lymph nodes are surgically removed to be investigated under the microscope to determine whether the cancer is present in them. The risk is that when as more lymph nodes are removed, there is always a higher risk of developing lymphedema. This condition is caused by the accumulation of the lymph fluid in the soft tissue of the arm which consequently leads to a swelling that may result in numbness, overall discomfort and sometimes infection.

Over the last years improvements in mammography have resulted in the detection of breast tumors at earlier stages. The early detection of breast cancer means that the patients and their doctor must determine whether a sentinel node biopsy is adequate to determine the extent of cancer spread. Recent studies suggest that the majority of women with small tumors detected on routine mammograms are good candidates for sentinel lymph node biopsy.