Melanoma: what it is, how to prevent and treat this type of skin cancer

Melanoma is the most serious type of skin cancer. It forms in melanocytes, the cells that give skin its colour by producing melanin. Melanoma is usually a large brown or tan spot with smaller darker spots, a mole that changes shape or colour or that bleeds, a lesion with irregular white, blue, red or blue-black borders. It can appear anywhere on the skin and is more common in women under 40 and men over 45.

Causes of melanoma Hereditary, smoking, excessive sun exposure

Melanoma occurs when there is damage to the DNA of melanocytes. While new cells normally push old cells to the surface of the skin to be eliminated, when there is an alteration in the melanocytes, the new cells grow in an uncontrolled manner and can form masses of cancerous cells.

The main risk factors for developing melanoma have been identified as:

- Excessive exposure to the sun and, with it, to ultraviolet (UV) rays.

- Having dysplastic nevi or atypical moles. They tend to be larger than other moles and have an abnormal shape and color.

- Dysplastic nevus syndrome (FAMMM). These are hereditary and people with this condition, in addition to having many dysplastic nevi, usually have at least one close relative with melanoma. These patients should perform a regular skin self-examination and need regular skin checks that will include photographs to compare the different examinations and check for changes.

- Have congenital melanocytic nevi. They are present from birth.

- Have xeroderma pigmentosum. Extreme sensitivity to UV-induced changes in the skin and eyes. It is hereditary.

- People with fair or very fair skin, light eyes, blond or red hair, and freckles are at higher risk of developing melanoma than those with darker skin tones.

- Have a weakened immune system.

- Be a woman under 40 years old or a man over 45 years old.

- Tanning artificially with tanning lamps or beds.

Melanomas are not always found in areas exposed to sunlight. So-called hidden melanomas appear in areas that may go unnoticed and usually affect people with darker skin. These hidden melanomas can appear under the nails (acral lentiginous melanoma), between the fingers, on the soles of the skin, on the genitals, on the scalp, in the eyes (ocular melanoma) and even in internal organs such as the digestive tract, vagina or urinary tract (mucosal melanoma).

Symptoms of melanoma Changes in moles or a new lump

The most common symptoms of melanoma are:

- Change in color or shape in a pre-existing mole.

- Appearance of a lump or spot on the skin that is atypical or unusual.

The standard that may raise a suspicion of melanoma is A, B, C, D and E.

- A for asymmetry (irregular shape).

- B with irregular edges

- C of varied color

- D diameter greater than 6 mm

- E for evolution or change of appearance

When in doubt, always consult a dermatologist.

Diagnosis of melanoma Skin exam and biopsy

The dermatologist can detect a melanoma during a visual examination, but confirmation will come with the analysis of a tissue sample (biopsy), which can be done by puncture, excision or incision.

The thickness and spread, if it has spread to nearby lymph nodes, will help determine the phase (stage) of the melanoma. To confirm spread, a sentinel lymph node biopsy can be performed, in which a dye is injected into the area where the melanoma was removed. The dye flows to the lymph nodes and allows the first nodes to absorb the dye to be removed and analyzed.

Stage I, II, III and IV indicate the extent of the disease. Stage I means that the disease is small and in its first phase; the other stages indicate greater progress, up to stage IV, which indicates that the disease has spread to other areas of the body.

Treatment and medication for melanoma Surgery, chemotherapy, radiation therapy and other therapies

If melanoma is in an early stage, it will be removed by surgery, removing the tumor, a border of normal skin, and a layer of skin tissue under the tumor. If melanoma has spread, surgery to remove the affected lymph nodes will be considered; chemotherapy and radiotherapy to eliminate cancer cells; biological therapy to stimulate the immune system; or targeted therapy with vemurafenib or dabrafenib, in cases of advanced melanoma, to attack the vulnerabilities of the cancer cells.

Prevention of melanoma Sun protection factor 50

It is recommended to use sunscreen with a protection factor of 50 throughout the year, especially on clear days and during the months of good weather, avoiding exposure to the sun during the central hours of the day. You should avoid spending too much time in the sun and use hats or caps that cover your head and sunglasses with a sun filter. The most sensitive people can use clothing with sun protection fabric. People who work outdoors should apply sunscreen with a protection factor of 50, use hats, caps or hoods.

Artificial tanning with sunlamps or tanning beds should be avoided.