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Sentinel-lymph-node-biopsy article

Breast Cancer: Efficacy of Sentinel Lymph Node Surgery

By Madison Kocher

Breast Cancer and Detection of Axillary Lymph Node Involvement

Because about 1 in 8 women in the United States develop invasive breast cancer over the course of her lifetime, it is important that newer and less invasive surgeries are explored to decrease the risks and morbidity of these procedures.  One technique that needs to be improved is the axillary lymph node dissection, in which six lymph nodes are removed from under the arm to assess for any spread of cancer from the breast area.  This procedure has a long recovery time and may cause nerve damage or continuous swelling of the arm.  A possible less invasive alternative to the axillary lymph node dissection is the sentinel node biopsy, which uses a special blue dye that is injected into the breast and followed to the closest and most affected lymph nodes that may possibly contain a spread of the cancer if it is not localized.  This technique limits the amount of lymph nodes extracted to about two or three, and decreases the recovery time and risks. 

The Question: Sentinel Lymph Node Surgery vs. Axillary Lymph Node Dissection

Sentinel lymph node surgery is reliable when patients have node-negative breast cancer, meaning there is no detection of spreading cancer into the lymph nodes.  However, there seems to be a high false negative rate when sentinel lymph node surgery is applied to women who initially had a node-positive breast cancer and received treatment of chemotherapy.  Simply, the less invasive surgery runs the risk of missing some of the lymph nodes that may contain a spread of the cancer and only extraction of all the lymph nodes in the axillary lymph node dissection surgery can detect it.  A study was conducted to determine the false negative rate when sentinel lymph node surgery (SLN) was performed on these women compared to axillary lymph node dissection (ALND). 

The Study

            The study examined a total of 637 women who met the study criteria. 603 of these women had breast cancer staged as cN1 (meaning there was disease in movable axillary lymph nodes) and 34 had cN2 (disease in fixed or matted axillary lymph nodes). These women underwent chemotherapy followed by both SLN surgery and ALND, and had at least one sentinel lymph node resected during the SLN surgery.

            Of the 525 women with cN1 disease with two or more SLNs examined, 310 had detectable nodal disease, of which 39 patients had detectable cancer in both procedures. 

            Of the 26 women with cN2 disease with two or more SLNs examined, 8 patients had residual nodal disease present in both SLNs and nodes removed on ALND. 

What this means for you:

            Of the breast cancer patients staged as cN1, there was a false negative rate of 12.6%, meaning that the SLN surgery was not sufficient to identify all the residual nodal disease present after chemotherapy.  However, they did find that using certain types of dye and resecting three sentinel lymph nodes instead of two had a significant decrease in the false negative rate.  This 12.6% false negative rate isn’t quite low enough to support the use of SLN surgery in everyone, but with different changes in technique and patient selection, this could be a good alternative for some patients.  Talk to your doctor about the right kind of surgery for you, and if sentinel lymph node biopsy may be a suitable alternative!

Citation:

Boughey JC, Suman VJ, Mittendorf EA, et al. Sentinel lymph node surgery after neoadjuvant chemotherapy in patients with node-positive breast cancer. JAMA. 2013;310(14):1455-1461.