Defining Lymph Node Metastasis
Lymph nodes normally swell when your body is fighting an infection. This is because more lymphocytes are produced to deal with the infection. In some cases, lymph nodes may swell because cancer cells are metastasizing. What exactly is metastasis and how are lymph nodes involved?
If you hear that a person’s cancer has metastasized, it means that the cancer cells from the organ of origin have moved to an organ that is located farther or in a different part of the body. This happens because the cancer cells have the increased ability to move and invade other cell areas. They usually do this by traveling through the blood stream or the lymphatic system. Breast cancer cells for example may find their way to the lungs, bones or other parts. These metastasizing cells however retain the original characteristics of their tumor of origin. Hence breast cancer cells that move to another part are still breast cancer cells.
In a lot of cases, cancer patients who do not know of their condition yet, may notice unexplained and prolonged lymph node swelling. They might also additionally suffer from high fever and chills but will not experience relief from common treatments. People who experience these symptoms should have themselves checked immediately. Lymph nodes that swell in this way may be a sign that cancer cells are moving from the original tumor.
Metastasis is usually a term reserved only for movement of cancer cells to organs that are distant. Swollen lymph nodes known as positive nodes near the area of the tumor are not always seen as an absolute indication of metastasis.
The reason why lymph nodes near the tumor swell when cancer cells are moving is because these lymph nodes are the drainage or filter areas for the organ or area affected by cancer. Positive nodes for breast cancer may thus be found near the armpit because this is the area where the lymph from the breasts drain.
Sentinel lymph nodes are the lymph nodes that cancer cells reach first in the act of metastasizing. As mentioned, these are the nearest nodes through which the lymph in the cancer affected area goes to. From the sentinel lymph nodes, the cancer cells can move on to succeeding lymph nodes and organs. Sentinel nodes are very important because doctors may evaluate them to discover the stage of cancer a person is in and what kind of treatment is appropriate.
Sentinel Lymph Node Biopsy
In some types of cancer, the sentinel lymph nodes are removed and evaluated in a laboratory to check for cancer cells. This procedure is known as sentinel lymph node biopsy.
The lymph nodes to be removed are identified by a blue dye which the doctor injects near the cancer area. The dye will make the sentinel lymph node visible through a scanner. A positive result means that cancer cells have begun to move while a negative result means that they are not yet metastasizing. Depending on your doctor’s assessment, positive results may mean that a patient may have to undergo more lymph node removal and tests.