Lymph Nodes in Cancer

The lymph system is a critical component of the body’s immune system. Comprised of a complex network of organs, nodes, ducts and vessels, the lymph system generates and transports lymph – a fluid rich in white blood cells, known as lymphocytes – from tissues into the bloodstream. The key engines of the lymph system are lymph nodes – small round or bean-shaped structures that fulfill multiple roles: producing disease-fighting lymphocytes, filtering lymph of bacteria and cancer cells, and signaling infection by swelling in response to heightened levels of pathogens.

Unfortunately, the lymph system is also a common pathway for cancer to spread or metastasize to distant sites. In fact, malignant cells will often infiltrate lymph nodes as an initial step of the metastatic process. The degree of lymph node involvement is instrumental to staging cancer, establishing suitable treatment regimens and offering an appropriate prognosis. Studies in a broad range of malignancies demonstrate that the greater the extent of lymph node involvement, the poorer the likely outcome.

Intraoperative lymphatic mapping (ILM) is a procedure done during surgery and uses injected dyes or nuclear-imaging agents to identify lymph nodes that may contain metastatic disease. 


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De Boer, et al., “Breast cancer prognosis and occult lymph node metastases, isolated tumor cells, and Micrometastases”, Journal of the National Cancer Institute, 2010, 102 (6): 410-425

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