Melanoma is malignant skin cancer which develops from the pigment-producing cells known as melanocytes. Globally, over 3 million skin cancer cases are diagnosed every year, of which newly occurred melanoma in over 200,000 people. Melanoma rates are increasing, including in younger people.
In recent years, the number of melanoma patients has grown also in Estonia. While in 2010, 188 new melanoma cases were diagnosed in Estonia, in 2015, the number of new cases was 272. As elsewhere, so in Estonia, the patients are becoming younger and younger – melanoma is the second most common cancer in young people of 15–29 years of age. Morbidity in women is higher compared to men until their 40s, thereafter more men than women get the disease. In Estonia, the mortality rate for melanoma is one of the highest in Europe.
The causes of melanoma are not entirely understood; however, the main risk factors are:
- ultraviolet light (the sun as well as tanning devices);
- sunburns (especially in childhood);
- I, II skin type;
- a lot of moles on the skin;
- congenital moles;
- atypical / dysplastic moles;
- affected family members or previous melanoma in the patient themselves;
Ultraviolet (UVA, UVB) light is the main risk factor of melanoma but also basal-cell carcinoma and squamous cell skin cancer. Melanocytes begin producing more melanin in response to ultraviolet light exposure, thereby tanning the skin. Melanin collects around the nucleus of a skin cell protecting the DNA from damage by light. However, the protective effect of melanin is quite weak. Therefore, there is no such thing as healthy tanning, because tanning shows that the DNA of skin cells has been damaged by ultraviolet light. Sunbathing, even without being sunburned, causes premature aging of skin cells and increases the risk of occurrence of skin cancer and melanoma.
Melanoma can develop anywhere on the skin, but also on mucous membranes, eyes and under the nails. Melanoma is more likely to start on the legs in women and on the back (trunk) in men. In 70–80% of cases, melanoma is already melanoma when it appears on the skin (a pigmented lesion which evolves and changes quickly), i.e. it can be detected already when it is a millimetre in diameter. In 5% of cases, amelanotic (no pigment) melanomas occur, which is why attention must be paid also to developed pinkish patches and nodes.
Nowadays we have dermoscopy, a good non-invasive method, to detect melanoma and examine moles (nevi). A dermatoscope is a device which enables to examine a mole under a magnifier helping the physician to decide whether the particular nevus has signs of malignance. If the physician sees under a dermatoscope an atypical / dysplastic structure in a mole which is not clearly malignant, the physician will discuss with the patient whether they should keep the nevus under observation or remove it surgically. If moles are kept under observation, pictures are taken of the patient’s moles which helps later to assess their dynamics. Atypia does not necessarily mean that a mole is malignant, it may show that for different reasons the cells in the mole have started to grow not like normal cells. Occurrence of an atypical / dysplastic mole increases melanoma risk by approximately 6%.
Five-year survival rate in case of early diagnosed and treated melanoma is almost 100%!
Videos about melanoma: