Stage 4 is the most severe stage of cancer. Metastatic cancer is another name for this stage. It conveys that the cancer has metastasized — spread to distant areas of the body.
Cancer is a group of diseases that cause rapid cell growth. Cancerous cells grow and reproduce uncontrollably in a certain area of the body, forming a tumor. As a tumor grows, the cancerous cells can spread to other areas of the body.
CausesStage 4 cancer develops when cancer cells break away from the primary cancer and spread to other parts of the body via the bloodstream or lymphatic system.
The National Cancer Institute states that when cancer cells spread, they first do so by growing into or invading nearby healthy tissue.
They then move through the walls of the nearby blood vessels or lymph nodes and trel through the bloodstream or lymphatic system.
The cancer cells will then stop in the small blood vessels at a distant location and attach themselves to the surrounding tissue. The cancer will grow, forming small tumors.
New blood vessels will grow, providing a blood supply that allows the cancer to continue to spread.