Hallmarks of Cancer
Activating Invasion and Metastasis
The sixth Hallmark of Cancer is the cell’s ability to activate metastasis. This means that cancer cells are able to spread to other parts of the body and form more tumors in new areas. Metastasis is often a key player in death resulting from cancer. Once cancer cells travel to other tissues in the body, they are able to invade and overtake that tissue.
Metastasis is the growth of a tumor at a location different from the original tumor. Cancer can spread to different parts of the body via blood vessels or through the lymphatic system.
The process of metastasis can be explained in three parts: invasion, intravasation, and extravasation. During the process of invasion, cells are able to detach from the original tumor and overtake surrounding tissues. During the process of intravasation, the cancer cells travel through the blood vessels and metastasize at the new destination. During the process of extravasation, the cancer cells integrate themselves in the layers of the new tissue through different biochemical interactions. Once the cancer cells are integrated, they can divide and proliferate to create a new tumor.
An example of this Hallmark of Cancer can be seen with lung cancer. The most common sites for metastasis of lung cancer are the adrenal glands, bones, the brain, the liver, and the other lung. Once metastasis begins, it is very hard to control. Most treatments of metastatic cancers do not cure the cancer, but rather slow the growth of the cancer and relieve painful symptoms. However, research is being conducted to find new ways to kill and stop the growth and spread of cancer cells. This treatment will focus on finding ways to use the body’s natural immune system to fight the cancer. It will also focus on trying to interfere with the steps of metastasis. 1
1 Metastatic Cancer. National Cancer Institute. https://www.cancer.gov/types/metastatic-cancer. February 6, 2017.