Watch out for the sun
Life on Earth cannot exist without the sun - but its ultraviolet rays can cause melanoma, a serious, aggressive and potentially deadly form of cancer. Here are simple ways to avoid it and to help with early detection
By David Moseley and the Health24 team
While the sun may be good for you, giving you a healthy glow, you shouldn't forget too much of a good thing could kill you.
The skin is the body's largest organ. Its purpose is to protect your otherwise exposed body. But this protective layer itself is vulnerable to attack. Skin cancer is the most common form of cancer in South Africa. It's also the most easily avoidable.
The exact causes of melanomas (cancerous moles that produce the most lethal strain of skin cancer) aren't clear. But the facts surrounding the disease are well-known: over-exposure to UV radiation from sunlight and sunbeds increases your risk of developing melanoma.
And of all skin cancers melanoma is the most deadly. Along with Texas and Australia, South Africa has the world's highest incidence of skin cancer. Nearly 10 000 new cases are diagnosed in SA annually.
Some people are more prone to developing melanoma than others. '' Most at risk are sun bingers,'' says Dr Ilsa Orrey, a dermatologist at Medi-Clinic Cape Town. '' These are people who stay out of the sun for most of the year and then fry themselves in one go.''
Just one serious sunburn at any age can increase your risk of developing skin cancer later in life, so if you bowl 40 overs on the trot to the kids in the garden and your neck turns the colour of a fire engine that's not good.
Other risk factors, Orrey adds, are a family history of skin cancer or an inherited tendency to dysplastic nevus syndrome (the medical term for a mole is a nevus). This means you'll have lots of atypical moles - larger than average and irregular in shape.
These atypical moles have a greater chance of becoming cancerous.
Are you at risk of melanoma?
- Do you have fair skin, light hair, a light eye colour or a tendency to burn easily?
- Did you have large brown moles at birth?
- Are your moles unusual - larger than 5 mm across, irregular in shape or multicoloured?
- Do you have more than 50 ordinary moles?
- Do you have a history of blistering sunburns - especially from when you were running around in the buff as a toddler, or from when you were a teenager?
- Do you spend a lot of time outdoors, working or playing sports? Are you a farmer, fisherman, engineer or geologist, or a cricket, golf or tennis player - anyone who often spends a large part of your day outside?
If you answer '' yes'' to even one of these questions you should keep a careful lookout for seemingly spontaneous changes to your skin.
Not all skin types are equally susceptible to developing melanoma. Skin types are graded from zero to six, with zero to three most at risk in the sun and four to six less likely to develop skin cancer.
The person is usually a redhead with freckles who always burns but never tans.
Skin that usually burns but can develop a tan.
Skin that sometimes burns but always gets a tan.
Type 6 can develop melanomas, says Orrey, but they're rare among black South Africans. Dermatologists have however noted an increase in melanoma in dark-skinned West Coast fishermen, illustrating that melanoma is not exclusive to types one to three.
Spot them in time
Constant vigilance is vital. Like speeding fines from highway cameras arriving in the mail, melanomas can suddenly appear with little or no warning. And they don't necessarily develop from existing moles - they can pop up anywhere and at any time. Many people develop melanoma on their back, head and neck, on their lower legs or even on parts of the body never exposed to the sun.
'' You don't feel ill at all,'' says Orrey. '' Most melanomas are diagnosed when patients aren't even aware of anything sinister developing on their bodies. The plus side is that if it's spotted early enough it's unusual to die from melanoma.''
The offending lesion will be removed quickly after being diagnosed and depending on the size of the '' invasion'' will leave you with a pretty good chance of survival. But if the lesion has penetrated just 1,5mminto your skin your chances of long-term survival are slim.
Studies carried out in Australia on patients 10 years after they'd been treated for melanoma found that:
- If the melanoma has not invaded deeper than 0,75mminto the skin your chance of survival can be 98 in 100.
- If the melanoma has penetrated deeper than 1,5mmthere's a one in 10 chance you won't survive beyond 10 years.
According to Orrey the age for developing melanoma is dropping - a direct result of increased awareness and earlier detection.
It's almost impossible to check your own body for possible melanoma and sometimes self-diagnosis can cause a few unnecessarily anxious moments. '' There are a few common mistakes that people make when they examine themselves." Irritated raised moles, seborrhoeic keratose (harmless skin lesions that develop the older you get, also called senile warts) and bleeds under the skin may look like melanomas.
Often the first sign of melanoma is a change in the size, shape, colour or feel of an existing mole. Most melanomas have a black or blue-black area - it may be '' ugly-looking''. Melanoma may also appear as a new mole. On the next page we give you the '' A-B-C-D'' of how to spot a melanoma.
Slip, Slop, Slap
South Africa's SunSmart and Australia's Slip, Slop, Slap skin cancer awareness campaigns drive home the same message: 'slip' on a shirt, 'slop' on sunscreen and 'slap' on a hat
Once is too much!
A single bad case of sunburn during childhood (or later) can cause irreparable skin damage and double the risk of skin cancer later in life. Beware, weekend sunbathers - you have a greater risk of melanoma.
Every exposure counts too and long and regular exposure to the sun can put you at risk as the damage is cumulative. Farmers, cricketers, golfers and others who have long, regular exposure to the sun also have a greater risk of the two other milder forms of skin cancer, squamous cell carcinoma and basal cell carcinoma.
Factor this in
Use an SPF of at least 15 on your body and an SPF of at least 30 on your face. The SPF number tells you how many times longer you can stay in the sun before burning than if you hadn't used any sunscreen at all. Always be sure to apply sunblock to your ears, nose, neck and hands - they're prone to bad burns.
Clutching at straws
A straw hat is a waste of time: it has an SPF of about eight only - the protective shade of a tree is about 10.
The average person has between 10 and 40 moles. They may be present at birth or may appear later, usually before the age of 40. About one in 10 people has at least one unusual mole.
A is for asymmetry. Look for moles with irregular shapes. If a mole has two very different-looking halves it could mean trouble. If the mole is symmetrical it should be fine.
B is for irregular border. Look for moles with irregular, notched or scalloped borders or swollen ridges - these are characteristic of melanomas. It's a good sign if the border is sharp and clearly defined; it's a bad sign if it blends into the skin.
C is for changes in colour, from light to dark or white to pale pink. Look for growths that have several colours or an uneven distribution of colour. If your mole is black or more than one colour it's best to have it checked out. Also watch out for a lesion that peels, heals and peels again, usually with a roughness you can feel rather than see; a lesion that forms an ulcer in the centre and doesn't heal; or a lesion that suddenly reappears. These rough lesions may itch.
D is for diameter. Look for new growth in a mole larger than about 5 mm (the size of the eraser on a pencil).
'' Take note of any change to a spot on the skin and of any spot that appears and doesn't heal normally,'' says Johannesburg melanoma patient and activist Peter Hers. '' You'll soon learn which are senile warts that can be ignored and which should be checked by your GP or dermatologist.''
Sun smart tips
Things you should do (From Cansa SunSmart)
- Wear sunscreen with a sun protection factor (SPF) of 15+. Regular application of sunscreen with an SPF of at least 15 during the first 18 years of life can lower the risk of some types of skin cancer by more than 75 per cent. But don't stop slapping it on when you're older than 18!
- Cover up! Wear clothes to protect the skin on your neck, arms, midriff and legs against the sun.
- Wear a hat (not a cap) that covers your neck and face.
- Seek shade and stay cool.
- Avoid direct sunlight from 10 am to 3 pm.
- Protect your and your child's eyes against UV rays. Avoid toy sunglasses; they do more harm than good. A child should wear sunglasses with at least 400 UV-ray protection.
- Don't expose babies younger than a year to direct sunlight.
- UV penetrates glass and water so protect your skin while in a vehicle or when you're swimming or snorkelling.
How to Examine your skin
The best time to do a skin self-exam is after a shower or bath. You should check your skin in a well-lit room using a full-length as well as a hand-held mirror. It's best to begin by learning where your birthmarks, moles and blemishes are and what they usually look and feel like. Check yourself from head to toe - don't leave out any area of skin.
- Look at your face, neck, ears and scalp. You may need to use a comb or a blow-dryer to part your hair so you can see better. Ask a relative or friend to check through your hair if it's too difficult to do yourself.
- Check the front and back of your body in the mirror then raise your arms and look at your left and right sides.
- Bend your elbows and look carefully at your fingernails, palms, forearms (including the undersides) and upper arms.
- Examine the back, front and sides of each leg. Also look between your buttocks and around your genital area.
- Sit down and closely examine your feet, including the toenails, soles and spaces between the toes.
Checking your skin regularly means you'll become familiar with what's normal for you. If you find anything unusual see your doctor right away.
Are you at risk?
If you have more than 50 ordinary moles you have a higher risk of melanoma.
Did you know?
Sunbeds and tanning lamps emit UVA rays and are unsafe. A welding torch also emits dangerous UVA rays.
Blame it on the sun
The sun's invisible ultraviolet (UV) rays are especially dangerous. They act as chainsaws that cut up the DNA in skin cells, thereby destroying the building blocks of the cells.
The results are visible as wrinkles and ageing. When it becomes impossible for the body to keep up with the constant repair the wrecked DNA under the skin's surface starts mutating, resulting in cancer cells which may appear anywhere on the skin.
UVA rays are the tanning rays. They're not blocked out by clouds and are dangerous throughout the day. They penetrate deep into the skin and cause serious damage to the deeper skin layers even before your skin turns red. These are the rays that bring about long-term damage such as wrinkles, sagging and discoloration.
The sun is responsible for 80 per cent of premature skin ageing, making sun protection one of the best defences against wrinkles. UVA rays also lay the foundation for skin cancer in the future and are associated with melanoma in the eye. Not all sunscreens protect against damage caused by UVA rays so look for packaging that clearly states the sunscreen protects against both UVA and UVB.
UVB rays cause redness and tan your skin slightly. It's the UVB rays that cause the pain, inflammation and redness known as sunburn. This sort of damage can happen within as little as 15 minutes and can continue to develop for up to three days after you've been exposed to the sun. You need a sunscreen that protects you against UVA and UVB as both can penetrate thick glass, a metre of water or wet cotton clothing.