Trying to determine the cause of Melanoma is very difficult. The best way to explain melanoma is to first discuss cancer in general. Normal cells in the body multiply only to replace worn-out or dying cells. Cancer cells grow and divide constantly and may spread to other parts of the body. These cells may stick together and form a tumor that will kill the normal and otherwise healthy tissue in that area. If these cancerous cells continue to grow they might spread through the blood stream or lymphatic system to new parts of the body.

What causes melanoma?

Melanoma cells are just like all other cancer cells in that they are cells that are growing out of control. The reason these cells deviate from the normal pattern is not known for sure. There are a few different causes that have been linked to melanoma by tests. The most obvious cause of melanoma is thought to be related to spending too much time in the sun, which results in exposure to ultraviolet (UV)radiation. When sunlight penetrates the top layers of the skin, ultraviolet radiation bombards the DNA inside the skin cells and damages it. UVB affects the outer skin layers while UVA penetrates more deeply. Both types of UV rays are thought to contribute to melanoma. To a degree, the body can protect itself against UV rays. The means of protection is melanin. Exposure of the skin to the sun results in increased production of melanin by the melanocytes. A tan is the result of melanin production. Although dark-skinned people (who have more melanin than light-skinned people) have lower skin cancer rates than the fair skinned, anyone can develop skin cancer.

Some researchers have found a molecule called trans-uroncanic acid that reacts to UVA radiation by releasing oxygen-free radicals. These are unstable particles that, in excess, can damage cell membranes and interact with genetic material contributing to the development of cancer. To protect the DNA from sun-induced damage, enzymes cause the cells in the upper layer to produce melanin that helps shield the sun's rays. After sunburn occurs some enzymes are released to make repairs using regenerated DNA or to signal damaged cells to kill themselves (apoptosis). Sometime genetic mutations or other factors may prevent apoptosis from occurring resulting in rampant cell growth that may lead to skin tumors. Ultraviolet radiation may also suppress the immune systems cancer-fighting ability (8).

Ultraviolet radiation is considered the main cause of melanoma. Many test have been done and some scientist think melanoma is sometimes genetically linked. A recent study reported that about 10% of people with melanoma had a defective gene called the p16 melanoma susceptibility gene. In its normal state the gene acts as a tumor suppressor; when defective it fails to stop the cells from multiplying and becoming cancerous (5). Other tests have shown that the risk of melanoma is also greater if one or more of a person's close relatives have been diagnosed with melanoma (2).