Check your skin too!

The two most common kinds of skin cancer are basal cell carcinomas, which originate in the deeper layer of the epidermis (outermost layer of skin), and spinocellular carcinomas, which start developing in the more superficial cells. In most cases, these are tumours that evolve slowly and rarely spread. Melanoma is a less frequent form of skin cancer (less than 5 percent of cases) but it is much more dangerous. This makes it even more important to recognise this kind of cancer early on before it starts to spread to other parts of the body. To provide some numbers, in Italy in 2020 about 14,900 new cases of skin melanoma were diagnosed: 8,100 among men and 6,700 among women. This is the third most frequent cancer in both sexes under the age of 50 (data from Airtum in 2021). Among the environmental risk factors, the most important is unquestionably exposure to UV radiation.

As with other forms of cancer, early diagnosis is important in the case of melanoma, this makes it possible to remove the tumour completely, reducing the risk of metastases, i.e., the cancer spreading to the lymph nodes or other organs, as far as possible. In Italy, for the time being at least, there are no plans to establish periodic nationwide screening schemes involving the entire population; it is considered more appropriate to encourage people to keep a close eye on their skin, learning to recognise warning signs that need further investigation by their doctor and possibly a specialist.

People whose job means that they have been exposed to the sun a lot over many years (e.g., farmers, sailors, fishers or ski instructors), are at greater risk of developing skin cancer. Excessive exposure to sunlight may also cause melanomas to develop, however, this form of the disease may occur in areas that are not normally exposed to the sun, such as the soles of the feet or between the toes. It has recently been suggested that there are different types of melanoma, some occurring as a result of sunburn, especially during childhood, and others arising in less exposed areas, without any relation to UV exposure. In a very small percentage of cases, genetic factors may also be involved.

Everyone should get their skin checked periodically, at least once a year, paying particular attention to the appearance of new marks or lesions, or changes to existing moles. People who are at greater risk should do this more frequently and their check-ups need to be more meticulous.

Ideally, the following people should check their skin once a month with the help of a mirror or another person:

• people with very fair skin
• people who tend to develop freckles or burn easily in the sun;
• people who got sunburn frequently in childhood or as teenagers.

People considered to be at higher risk of melanoma should ask a dermatologist for more detailed instructions on how to perform this monthly check-up. The reasons for this include:

• because they have already had the disease;
• because they have a great many moles, or some which look unusual (although only half of all melanomas arise on a pre-existing nevus);
• because their immune system has been weakened, such as people who have had an organ transplant.

Regular check-ups by a skin cancer expert would be appropriate for people who:

• have already had more than one melanoma in their lifetime;
• have at least three family members who have been diagnosed with melanoma or pancreatic cancer;
• were born with what’s known as a giant nevus (over 20 cm in diameter).

When this disease recurs several times in one or more family members, it is possible that there are hereditary mutations in their genetic makeup that favour its onset. Several genes have been identified that, on mutation, can lead to greater susceptibility to skin cancer. The CDKN2A gene, for example, is the one most frequently found to have mutated in the hereditary form of melanoma, in recent years however, researchers have also highlighted the role played by other genes. Genetic tests can be carried out to detect these abnormalities, but regardless of the outcome of the tests, all first- and second-degree relatives of people with melanoma who belong to families with multiple cases should always be considered to be at risk. Individuals carrying mutations are at a 50-times higher risk of developing the disease than the general population. Nevertheless, other risk factors, such as skin type or exposure to the sun, should not be overlooked.

Anyone who is not in the higher risk categories just needs to check their skin all over periodically. This can be done alone or with the help of another person, ideally in a well-lit room, and using mirror to examine parts of the body that are otherwise out of sight.

As a general rule, the emergence of any new marks on the skin that don’t go away with time, such as small swellings, nodules or ulcers, especially areas that are exposed to sunlight, should be reported to a doctor, because they could be forms of skin cancer.

To recognise potential melanoma, dermatologists suggest using this simple ABCDE to remember the most common characteristics of this kind of skin cancer. ABCDE stands for asymmetry, border, colour, diameter and evolution. These are the characteristics of skin damage that need to be treated with suspicion:

• Asymmetry – which means the shape of the mark isn’t uniform (one half may be bigger than the other;
• Border – melanoma often has borders that aren’t well defined or are irregular in shape;
• Colour – melanoma lesions are often very dark, or vary in colour or shade within the same mole;
• Diameter – larger than 6mm in diameter, which is bigger than common moles;
• Evolution – Melanoma will often change characteristics, such as size, shape or colour, over time.

Other warning signs that need to be reported to a doctor without delay are: a mole that starts to bleed spontaneously, one that has reddened round the edges, itches, or burns, and when the surface of a mole changes in appearance from smooth to rough.

If one or more of these signs are detected it is a good idea to contact a doctor, who will probably arrange for referral to a specialist.

Usually, the specialist will look closely at the mole or mark, this is called a dermoscopy (or epiluminescence), it involves examining the lesion found on the skin with a handheld instrument called an optical dermatoscope, which helps the specialist to recognise possible malignant forms of skin cancer. It works by magnifying the lesion, and using a light source and a camera, or microscope, the specialist can analyse its internal structure. It is possible to recognise different types of skin cancer in this way, and the doctor may also take photographs to look for changes over time, if necessary.

If the specialist doctor thinks it would be a good idea, because there are doubts as to whether the lesion may be cancerous, a procedure called an excisional biopsy can be performed. A cut is made through the skin and the suspicious area is removed completely along with a small amount (2-3 mm) of healthy tissue around the area. Histological tests are then carried out on the sample in a laboratory, meaning that it is examined under a microscope by an anatomical pathologist. If the tests show that the lesion is malignant, further examinations and treatment may be necessary, including a more extensive operation to remove any remaining cancer cells.