Cutaneous melanoma

Cutaneous melanoma is a cancer that originates in cells known as melanocytes. These cells produce melanin, which is why the tumours are usually coffee coloured or black, but they can also be pink, pale coloured or white. Overall, cutaneous melanomas represent approximately 1% of all tumours in both sexes, and every year 15 out of every 100,000 people are diagnosed, a figure that is increasing in nearly all European countries.

Cutaneous melanomas can develop on any part of the skin, but they are more frequent on the chest and back in men and the legs in women. The neck and face are other common sites. Having skin with a dark pigmentation reduces the risk of melanoma in these more common locations.

Melanomas are much less frequent than other types of skin cancer, but they are more dangerous, because they grow more quickly and they are very likely to spread to other parts of the body if they are not discovered and treated in time.

Symptoms

The first signs of a melanoma are as follows:

• A change in an existing freckle.
• The formation of a new lump on the skin  that is pigmented or of unusual appearance.

Melanomas do not always start with a freckle: they can also appear on normal-looking skin and can form on any part of the body. They very often appear on parts of the body that have been exposed to the sun, such as a person’s back, legs, arms or face. They can also occur on parts that have little exposure to sunlight, such as the soles of the feet, the palms of the hands and in the nail beds. These hidden melanomas are more frequent in people who have darker skin.

Who is affected by the condition?

In Spain, the condition especially affects women, with an average initial-diagnosis age of 55, and men at an average age of 57. For white individuals, the incidence of cutaneous melanoma is increasing at an alarming rate, in all Cancer Registries. In Europe, it is the ninth most frequent cancer, with around 200,000 cases diagnosed every year. Although it only represents between 1.5 and 1.7% of skin cancers, it is responsible for 65% of deaths from skin cancer. This figure is stable in spite of the increased incidence, probably because of early diagnosis, which is the most important factor, and improvements in treatment.

The reason why melanoma occurs is unclear, although some risk factors have been identified, which should be taken into account:

• Exposure to ultraviolet light: Sunlight increases the risk of melanoma, especially if sunburn occurs, and still further during childhood. Tanning booths should also be avoided.
• Freckles: Someone who has a lot of freckles is more likely to suffer melanoma.
• Type of skin: People with fair skin are at a higher risk.
• Family history of melanoma: The risk of suffering a melanoma is greater if one or various first-degree relatives have had one. Approximately 10% of all people with melanoma have a family history of this illness.
• Personal history of melanoma or other skin cancers: Someone who has already suffered a melanoma has a higher risk of suffering it again.
• Weakened immune system: People with a weakened immune system, due to certain illnesses or medical treatments, are more likely to suffer from the illness.
• Advanced age: Melanoma is more likely to be present in people of more advanced age, due to accumulated sun damage.

Diagnosis

It is usually diagnosed after observing a suspect freckle that presents alterations known as (1,2,3,4):

1. Asymmetrical shape.
2. Irregular or poorly-defined edges
3. Changeable colour that varies according to the areas.
4. Its evolutionary dynamics, such as itching, bleeding, etc.

For this reason, if a new, unusual freckle is found, or a change is noted in an existing one, it should always be examined by a dermatologist, as early diagnosis is vital in this illness. The tests and procedures used to diagnose cutaneous melanoma include the following:

• Physical examination: The doctor will ask you questions about your medical history and examine your skin to search for signs that may indicate the presence of a melanoma.
• Extraction of a tissue sample for analysis (biopsy): In order to determine whether a suspect cutaneous lesion is a melanoma, the doctor may recommend the extraction of a skin sample for analysis. The sample is sent to a laboratory for examination.

Typical treatment

The recommendations for treatment depend on many factors, such as the thickness of the primary melanoma, the possibility that the cancer has spread or the presence of specific genetic changes in the melanoma cells, among others.

However, surgery is the main treatment against local and regional melanoma. It may also be an option for combating metastatic melanoma. If surgery is not an option, the melanoma can be called “unresectable”. In order to recommend a specific treatment plan, the doctors will take into account the state of the illness and the risk of relapse in each person. Subsequently, in accordance with the state, a systematic treatment can be indicated for a period of one year. In recent years, the treatment of melanomas that have spread extensively through the body has changed, as the newest forms of immunotherapy and targeted drugs have proven to be more effective than chemotherapy.

Typical tests

A complete physical examination must be conducted, including a general examination of the skin. The purpose of these tests is to identify risk factors and signs or symptoms that may indicate that the melanoma has spread beyond the original site. For most low-risk melanomas, less than 1 mm thick, it is generally unnecessary to carry out an additional search for metastasis or spreading.

In the case of people with high-risk melanoma, more exhaustive tests may be considered, including the following:

• Ultrasound: Creating an image of the internal organs.
• Exploration using computed tomography (CT): Creating images of the internal body using X-rays, taken from different angles. If the melanoma has spread, it can be used to measure the size of the tumour.
• Magnetic resonance (MRI) This uses magnetic fields instead of X-rays, in order to produce detailed images of the body, and it can be used to measure the size of the tumour.
• Exploration via positron emission tomography (PET) or PET-CT: This is a way of creating images of the organs and internal tissues. A small quantity of a radioactive sugar is injected into the patient's body. This is absorbed by the cells which use the highest amount of energy. Subsequently, a scan detects this substance in order to generate images of the internal body.

Prevention for reducing the risk of melanoma appearing

- Limiting exposure to ultraviolet rays.

• Seek out shade and avoid direct exposure to sunlight between 11 am and 6 pm.
• Use hats, caps, shirts or tee-shirts with solar filters.
• Use sunglasses.
• Use sun protection, several times, every day of the year, even on cloudy days.

- Avoid tanning booths.

- Protect children from the sun, to avoid sunburn.

- Pay attention to unusual freckles when examining your skin. If in doubt, it is always a good idea to make an appointment with a dermatologist, for a thorough check up.