What is a Melanoma?

Is a Melanoma Dangerous?

Melanoma is a serious form of skin cancer that occurs when a tanning cell (melanocyte) in the epidermis of the skin becomes cancerous. Melanoma is the eighth most common cancer in Australia, so we can assume that it is about as frequent in white people in South Africa. The number of melanoma cases diagnosed annually is increasing faster than for any other cancer. Using recent figures from Australia, it is estimated that 1 in 25 white people in South Africa will develop a melanoma during their lifetime. If left untreated, melanoma can spread (metastasise) to other parts of the body and this can be fatal. Fortunately, when detected at an early stage, melanoma treatment is often effective in limiting the spread of the disease and curative in a significant percentage of people. 

What Causes a Melanoma?

Ultraviolet Radiation and the Sun

The biggest cause of melanoma is damage to one's skin by ultraviolet radiation (UV) from the sun (sunburn). UV radiation directly damages the DNA in one's tanning cells and if this causes activation of a cancer gene then a melanoma will result. Multiple sun burns (especially severe ones with blistering) over one’s lifetime significantly increase one’s risk of getting a melanoma. The effect of sun burns is cumulative. Frequent use of sun beds (which have very high intensity UV light) has been estimated to increase the risk of developing a melanoma by as much as 250%.

Dysplastic Naevus Syndrome

Much less commonly there is a significant genetic component to the development of a melanoma. People with an increased genetic risk of developing melanoma have multiple abnormal looking freckles (dysplastic naevi) and this is called the dysplastic naevus syndrome, also known as atypical mole syndrome. Mole mapping is recommended for these patients. 

Preventing Further Melanomas

People who have had melanoma are at an increased risk of developing another melanoma. 

The development of a melanoma is a sign that there has been enough damage to the skin for a melanoma to have occurred. It also means that there are other damaged cells that may be close to turning into melanomas. Any further damage by UV light from the sun may be enough to convert these damaged cells into melanoma cells, so it is very important to protect one's skin from the sun.

The best way of protecting one's skin from the sun is to keep indoors. This is clearly not practical, so if one is spending time outdoors then the best way of protecting the skin is to cover up with UV-protective clothing. Wear a hat (especially if one's hair is thinning) and apply sunscreen to exposed skin. The sunscreen should have at least a factor 30 UVB protection with a 4 star UVA protection rating, be easy to apply and not too greasy (or it won't be used). Sunscreens do not cause skin cancers, despite what one may read in fake news articles.