DEAR DOCTOR K:
My doctor just discovered that I have melanoma, but didn’t really explain the treatment. Can you tell me what I’m in for?
Melanoma is skin cancer that begins in the melanocytes — cells that give skin its color. Usually these cells first form a precancerous condition called a dysplastic (diss-PLAS-tik) mole. Then the cells turn cancerous and start to reproduce aggressively.
When that happens, the melanoma grows in size. Unfortunately, some of the cells also can shake loose from the tumor and spread throughout the body. When that happens, the cells first spread to the local lymph nodes, then on to the rest of the body. If melanoma has not spread, it can be cured.
If your melanoma appears in just one spot, it will be surgically removed. The doctor removes the visible part of the tumor. He or she will also remove some healthy skin around the tumor. (The exact amount will depend on the size of the tumor.) The extra skin is removed because it can contain microscopic bits of the cancer. You want all of the cancerous cells removed.
In some cases, the doctor may perform a procedure during which the tumor is shaved away one thin layer at a time. Each layer is examined under a microscope as it is removed. This technique helps the doctor remove as little healthy skin as possible.
Your doctor may also want to check if the melanoma has spread to nearby lymph nodes. These small structures are part of the immune system. To check, your doctor may inject a radioactive liquid into the tumor. The liquid flows through the natural drainage pathway that connects the tumor to nearby lymph nodes.
The drainage path can be tracked. The first lymph node along the path is called the sentinel node. This node is removed and examined for cancer cells. If the sentinel node has no cancer, the other nodes are most often cancer-free. If cancer is found in the sentinel node, all the lymph nodes in the area will likely be removed.
In addition to surgery, treatments for melanoma include immunotherapy. This treatment strengthens the immune system against the cancer. Recently developed techniques for stimulating your immune system to attack the cancer have sometimes been dramatically effective. Chemotherapy and radiation therapy are also available, but tend to be less effective.
Newer drugs target specific genetic changes seen in people with certain forms of melanoma. For example, about half of melanomas have genetic changes (mutations) in a gene called BRAF. This mutation signals melanoma cells to grow and divide quickly. Drugs that inhibit BRAF and related proteins are now available.
The sooner melanoma is identified and treated, the better. Everyone should inspect their skin regularly. If you notice any moles with uneven color, an irregular border, or a border that changes over time, see your doctor. (I’ve put a photo of a cancerous mole, below)
The deadliest form of skin cancer occurs when melanocytes, pigment-making cells in the basal layer or in surface moles, begin reproducing uncontrollably, spreading to distant parts of the body.