Are people with darker skins immune to skin cancers? A Hong Kong doctor explains
Having more melanin does offer slightly more protection against harmful UV rays, but darker-skinned people are still at risk and should protect themselves
Are naturally dark-complexioned people immune to skin cancer?
The short answer: No
The facts: you may have heard that people with darker-complexions can get away with not wearing sunscreen because the melanin in their skin protects them from skin cancer. While it is true that fair-skinned folks are more susceptible to the damage caused by harmful ultraviolet rays, and that melanin does have a slight protective effect against the sun, it doesn’t mean that darker-skinned people are safe from skin cancer.
According to Dr Nicola Chan, a specialist in dermatology based in Sheung Wan, skin cancer develops when components in the skin start to develop rapidly and abnormally, eventually becoming a tumour.
“Skin cancer is most commonly caused by cumulative sun exposure or the frequent use of tanning beds. In a small number of cases, the condition may develop due to genetic factors, severe burns, or repeated exposure to radiation, such as from X-rays,” says Dr Chan.
Fair-complexioned people do not have sufficient melanin, the substance that not only gives skin its colour but also protects it from damage caused by ultraviolet radiation. As a result, Dr Chan says that they burn more easily in sunlight. She adds that fair-complexioned people are at a higher risk of developing skin cancer overall.
Naturally dark-complexioned people have more melanin in their skin. This dark pigment creates a protective barrier between the skin and ultraviolet rays. Melanin only blocks out these dangerous rays to a point, though, so even people who are naturally dark-skinned are vulnerable to developing skin cancer.
“All complexions are vulnerable,” Dr Chan adds. “Whatever your complexion, whether or not you develop skin cancer depends on how much ultraviolet light you’ve been exposed to over the years, the severity of the sunburns you’ve experienced, and so on. Sunburn is a sign of DNA damage, so, if you’re naturally dark-skinned and have experienced many severe sunburns … you certainly increase your chances of developing melanoma and other skin cancers.”
A melanoma subtype, acral lentiginous melanoma, is more common among people with darker skin types, including in Asia. It tends to occur on the palms of the hands and soles of the feet, and is believed to be due more to genetics than to sun exposure, Dr Chan says.
Darker-skinned people with skin cancer melanoma tend to fare worse than fair-skinned people with the same condition. An American study (“Racial disparities in melanoma survival”) published in November 2016 in the Journal of the American Academy of Dermatology revealed that, although the incidence of melanoma was higher among whites than non-whites, overall survival for the disease in non-whites was significantly lower.
And among non-whites, blacks had the shortest survival time compared to Hispanics, Native Americans, Pacific islanders, and Asian Americans. The proportion of later-stage melanoma (stages two to four) was also found to be greater in blacks compared with whites.
The study certainly points to the importance of regular self-checks. The earlier the cancer is detected, the faster treatment can get under way and the better the chances of survival.
Dr Chan says to look out for new moles and changes in existing moles. “Look for changes in the symmetry, border, colour, and diameter or size of the lesion. In fact, any change at all.”
It’s never too late to protect your skin from the sun’s damaging effects. Dr Chan recommends wearing sunscreen every day – even on cloudy days, since up to 80 per cent of ultraviolet rays can pass through clouds.
Babies and toddlers aged six months and older can wear sunscreen, too – and should, since their skin is especially delicate. Choose a product that is suitable for their age and skin type.
Avoid direct sunlight between 10am and 3pm – when the sun’s ultraviolet rays are the strongest and most dangerous.
Wearing protective clothing can help, too. Dr Chan recommends covering your arms with long-sleeved outfits, and wearing wide-brimmed hats to protect your neck, ears and sides of your face.