Lymph nodes are small clumps of immune cells that act as filters for the lymphatic system. The lymphatic system runs throughout the body (like the circulatory (blood) system) and carries fluid and cells.
If breast cancer spreads, the lymph nodes in the underarm (the axillary lymph nodes) are the first place it’s likely to go.
Figure 4.4 shows the location of the axillary nodes.
Lymph node status is highly related to prognosis (chances for survival).
Prognosis is better when cancer has not spread to the lymph nodes (lymph node-negative) .
The more lymph nodes that contain cancer, the poorer prognosis tends to be .
Learn about lymph node status and breast cancer stage.
Lymph node status is related to tumor size. The larger the tumor, the more likely it is the breast cancer has spread to the lymph nodes (lymph node-positive) .
Positive lymph nodes can sometimes be felt during a physical exam. However, a pathologist’s exam of the lymph nodes removed during a biopsy or surgery is needed to determine lymph node status.
During a physical exam, a health care provider feels under the arm to check if the lymph nodes are enlarged. If the lymph nodes feel enlarged, it’s likely the cancer has spread. However, if the lymph nodes don’t feel enlarged, it doesn’t mean the nodes are negative (cancer-free).
The pathologist checks the nodes under a microscope. Nearly one-third of women with negative lymph nodes based on a physical exam have nodes with cancer found during the pathology exam . And, some women with enlarged nodes during a physical exam have cancer-free nodes .
Sentinel node biopsy is the most common way to check the axillary lymph nodes for cancer.
In some cases, an axillary dissection (which removes more tissue than a sentinel node biopsy) is done.
Learn more about sentinel node biopsy, axillary dissection and lymph node assessment.
For a summary of research studies on sentinel node biopsy and lymph node status, visit the Breast Cancer Research Studies section.
At this time, axillary dissection instead of sentinel node biopsy is recommended for people who have locally advanced or inflammatory breast cancer [15-16].
However, the accuracy of sentinel node biopsy in these cases is under study.
Facts for Life: Axillary Lymph Nodes
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