While squamous cell carcinoma and basal cell carcinoma are more common, malignant melanoma is the most deadly of the three. The cases of melanoma has been increasing steadily over the last 50 years and is not letting up. With 34,000 new cases in 1995 and a prediction that by the end of the century, 1 in every 75 persons will have some form of melanoma, things do not look good for our skin. Another interesting statistic is that the rate of increase of melanoma during the past decade has been second only to lung cancer in women. All the indicators point to the fact that malignant melanoma is growing into a major health risk among the population and is not letting up.
Most skin diseases are caused by a history of sun exposure over time, but melanoma is different. Malignant melanoma is caused by intermittent, but intense sun exposures that usually include sunburns. The main reason melanoma is growing so fast in the population is that most people get sunburns many times during the year. Those who are constantly in the sun are more likely to receive the other skin cancers mentioned like basal cell carcinoma or squamous cell carcinoma.
This form of skin cancer originates in the skin cells called melanocytes, which produce the dark pigment melanin. These cells are also found in the respiratory tract and surround nerve cells. When one of these cells is transformed into a cancer cell, the danger begins when the cell enters the blood stream or lymph system. From here the new cancerous cell can invade other body tissues and multiply.
When melanoma has been detected, tests have to be done to figure out how far the cancer has spread. This process is called staging. There are 5 stages in the life of melanoma and each is progressively worse. In the first stage, the cancerous cells are limited to the upper epidermal layer and have not invaded the deeper skin. The next stage is defined by a tumor that is less than 1.5 millimeters thick and has only spread to lower levels in the skin. When melanoma is in stage 3, the tumor is 1.5 to 4 millimeters thick and can be found in the lowest layers of skin. The next stage shows a tumor thicker than 4 millimeters, satellite tumors in the lymph or blood system, and or body tissue below the skin that shows tumor growth. The last stage of melanoma is when tumors have spread to internal organs or lymph nodes far away from the original site. It is best that the melanoma be discovered before stage 3 because after that many tumors form throughout the body.
The sun alone does not cause malignant melanoma. Genetics also can contribute to the risk factor. Moles are found all over the body and have been linked to certain genes. The average person has 25 moles as an adult and some of these contain cells similar to melanocytes. Because of these melanocytes being in the moles there is an increased chance of getting malignant melanoma. UV exposure will always be the overriding factor in getting malignant melanoma, but many other conditions contribute.