Melanoma is the most dangerous form of skin cancer because it has a high likelihood of spreading or metastasizing throughout the body. But where does melanoma spread to and how does it get there?
Where it begins
Melanoma begins in melanocytes cells (the cells that create pigment) in the deepest layer of skin, also known as the hypodermis or subcutaneous tissue. When these cells become damaged, mutations can occur and the mutated cells can reproduce themselves rapidly, eventually forming a tumor and taking over surrounding tissues.
Melanomas can develop from existing moles or skin growths, but, more commonly, they will start as a new growth. At this point, the melanoma is only present in the skin, also known as stage one and two melanoma.
Spreading to the lymph nodes
When a tumor gets too big, it requires more oxygen and nutrients to survive. This is when the tumor sends out signals that cause new blood vessels to grow into the tumor (a process called angiogenesis), bringing the nutrients and oxygen it needs. After angiogenesis occurs, cancer cells are now able to break off and enter the bloodstream.
They can also break off and spread through the lymphatic system (a system which carries fluid throughout the body and is a vital part of the circulatory and immune system).
When this happens, the cancer cells can now settle and take root in a new area of the body. Once the cancer cells have spread to the lymph nodes it’s considered stage three melanoma.
Spreading to the organs
After the cancer has spread to the lymph nodes, the lymph nodes and/or blood vessels help the cancer move to other areas of the body, like the organs. Which organ it will spread to first, varies depending on where the cancer started, the type and the person, but the liver, lungs and brain are common sites for metastases.
Once it’s in the organs, it is known as stage four melanoma.
Early detection prevents melanoma from spreading
While there are still many mysteries when it comes to why and how melanoma develops, it is certain that the sooner melanoma is discovered, the lower the chances of it spreading and becoming deadly. That’s why it’s essential to perform regular skin checks and know the symptoms of melanoma so you can catch it early.