Melanoma is a malignant skin tumour that develops from pigment-producing cells called melanocytes. Every year, more than 3 million cases of skin cancer and over 200 000 cases of melanoma are diagnosed worldwide. The incidence of melanoma is rising steadily, with younger and younger people being affected.
In recent years, the number of melanoma patients has also increased in Estonia. If 2010. In 2015, 188 new cases of melanoma were diagnosed in Estonia. In 2007, there were already 272 new cases. Patients in Estonia are getting younger and younger – melanoma is the second most common cancer among 15-29 year olds. Women have a higher incidence of the disease than men up to 40 years of age. From this age onwards, melanoma affects more men than women. Estonia has one of the highest melanoma mortality rates in Europe.
The causes of melanoma are not definitively known, but the main risk factors are:
Ultraviolet radiation (UVA, UVB) is a major risk factor for melanoma as well as basal cell carcinoma and squamous cell carcinoma. When exposed to ultraviolet rays, melanocytes produce more melanin, which causes the skin to turn brown. Melanin builds up around the nucleus of skin cells to protect DNA from the damaging effects of radiation. However, the protective capacity of melanin is relatively low. Therefore, it can be said that there is no such thing as a healthy tan, a tan is a sign that the DNA of skin cells has been damaged by ultraviolet radiation. Tanning, even without sunburn, causes premature ageing of skin cells and increases the risk of skin cancer and melanoma.
Melanoma can occur in all areas of the body, including the skin, mucous membranes, the eye and under the nails. In women, the most common site of melanoma is the top of the legs, in men it is the back. In 70-80% of cases, melanoma is already melanoma (a rapidly developing and changing pigmented mass) when it appears on the skin, meaning that it can be diagnosed as early as one millimetre. In 5% of cases of amelanotic (non-pigmented) melanoma, attention should always be paid to the pink patches and nodules that appear.
Nowadays, there is a good non-invasive method for detecting melanoma and checking moles (nevi) – dermatoscopy. A dermoscope is a device that allows a magnified view of the mole and makes it easier for the doctor to decide whether or not there are signs of malignancy in the mole. If the doctor sees an atypical/dysplastic structure in the mole on dermatoscopy, which is not clearly malignant, it is discussed with the patient whether this nevus should remain under observation or be surgically removed. In the case of monitoring, images of the patient’s birthmarks are taken so that they can later be assessed dynamically. Atypia does not necessarily mean malignancy, but that for various reasons the cells in the birthmark have started to grow differently from normal cells. The presence of an atypical/dysplastic birthmark increases the risk of melanoma by about 6%.
For melanoma detected and treated early, the average 5-year survival rate is almost 100%!