What is skin cancer?
Skin cancer is the most common type of cancer among white populations, in the UK and worldwide.
Most are easy to treat and pose only a small threat to life, but one type, melanoma, is difficult to treat unless detected early. Over the past 25 years, rates of melanoma in the UK have risen faster than any other common cancer.
There are three principal types of skin cancer, which can have different symptoms and appearances.
Basal cell carcinoma (BCC) affects a type of cell within the top layer of skin. It’s a slow-growing cancer and doesn’t usually spread to other parts of the body.
BCC affects all sun-exposed areas of the body. The main symptom is a small, painless, pink/brownish-grey lump, with a smooth surface, blood vessels and a waxy or pearl-like border. The lump grows, developing a central depression with rolled edges.
Squamous cell carcinoma (SCC) involves another type of cell in the top layer of skin. It usually affects the face and the main symptom is an area of thickened, scaly skin that develops into a painless, hard lump, reddish brown in colour with an irregular edge. The lump becomes a recurring ulcer and doesn’t heal.
These two types are known as non-melanoma skin cancer. They are usually slow growing, occur on sun-exposed areas of the skin and rarely spread.
Melanoma skin cancer can occur anywhere on the body and is more dangerous. It’s related to the common mole and changes in the appearance of moles on your body should be checked by your GP.
Malignant melanoma tends to spread much more rapidly through the bloodstream than the other two types of skin cancer. It affects the cells that produce the skin’s colouring, and if not treated successfully can spread to the liver, lungs or brain.
The main symptom is a quick-growing, irregular, dark-coloured spot on previously normal skin or in an existing mole that changes size, colour, develops irregular edges, bleeds, itches, crusts or reddens. If an adult has a growing, changing, brown or black mark which cannot be covered by the blunt end of a pencil, this should be shown to the doctor straight away.
Occasionally, melanoma may present with swollen lymph glands or rarely in unusual places including the sole of the foot, mouth or eye. If melanoma is diagnosed, then further tests will be done to see if the cancer has spread beyond the skin to other parts of the body. This may involve taking x-rays and scans to look at the liver, brain and lungs.
To find out if it’s skin cancer and if so which type, a doctor will carry out a biopsy, removing all or part of the suspicious growth for analysis.
Although scientists have found that those with lighter skin are far more vulnerable to skin cancers, the main cause of skin cancer is over-exposure to the sun’s harmful UV rays. A suntan isn’t healthy – it’s a sign of skin damage. It’s thought the UV radiation in sunlight causes subtle cell damage which can lead to cancerous changes.
Non-melanoma skins cancer results from prolonged sunlight exposure over many years. The main cause of melanoma skin cancer is exposure to short periods of intense sunlight; the kind of exposure people get on a two-week holiday.
Rates of skin cancer of all sorts are extremely low among dark-skinned people. Men are more likely to develop cancers on their neck, shoulders and back, whereas in women they’re more likely to appear on the legs and arms.
Diagnosis of skin cancer can usually be made by your GP or hospital specialist by simple skin examination. Sometimes, the skin cancer will need to be removed by a small operation or biopsy; both for treatment and lab testing. Other routine tests, including X-rays and scans aren’t usually required.
Non-melanoma skin cancers are usually treated by a common operation to cut out the affected area under local anaesthetic. Another method used on smaller cancers is cryosurgery, in which liquid nitrogen is applied to the tumour to freeze it and kill the cells, which simply shrivel and drop off.
Some cases of basal cell carcinoma may be suitable for photodynamic therapy, which uses a cream to sensitise the tumour and then exposes it to high intensities of light to destroy it.
In the case of melanoma, if there is a suspicion that the cancer may have spread beyond the skin layer, chemotherapy or biological treatment such as interferon may be given to attempt to eradicate skin cancer cells in other parts of the body.
About 1,800 people die from melanoma skin cancer annually in the UK. Even so, nearly 80 per cent of men and over 90 per cent of women are alive at five years following treatment.
The best way to prevent skin cancer is to avoid too much time in the sun. You don’t have to be sunbathing to get burned. You can get too much sun while walking to the shops, driving a car with the windows down, even under light cloud cover. Time of day and location are important too. The intensity of UV radiation increases during the middle of the day, between April to September, nearer the equator and at higher altitudes.
How to protect yourself and your children:
- Stick to the shade between 11am and 3pm
- Cover up with clothes, a wide brimmed hat and sunglasses
- Apply a high-factor sunscreen (minimum SPF15 and three stars) regularly
- Drink plenty of water to avoid overheating
- Avoid using sun lamps or sunbeds
Many moles aren’t cancerous, but it’s vital to keep an eye on any you have. Watch out for moles that change shape or colour, become bigger, itchy or inflamed, or that weep or bleed. If you notice any changes or are worried, get them checked by a doctor.