Sunscreen Prevents Precancerous Spots

Sunscreen Prevents Precancerous Spots:

Applying sunscreen every day rather than only on sunny ones makes a big difference when it comes to fighting the first signs of skin cancer. A new study shows that daily use of sunscreen is much more effective than sporadic use in preventing precancerous skin growths called solar keratin’s or SKs.
The skin lesions are the earliest forms of the most common types of skin cancer caused by sun exposure, basal cell carcinoma and squamous cell carcinoma. People who have SKs are up to 12 times more likely to develop these forms of skin cancer than others.
Despite these risks, researchers say little is known about sunscreen’s role in preventing these early markers of skin cancer. In this study, researchers compared the effects of daily versus occasional use of sunscreen use in reducing the number of SKs in 1,621 adults living in Queensland, Australia from 1992 to 1996.

One group was instructed to apply a water-resistant sunscreen with an SPF (sun protection factor) of 16 each morning to their head, neck, arms, and hands, and the other group was told to use sunscreen at their own discretion.
People who used sunscreen daily developed significantly fewer SKs than the occasional sunscreen users, and the protective effects of daily sunscreen use were especially strong in the first two and a half years of the study.
For example, the increase in SK counts from 1992 to 1994 in the group that used sunscreen daily was about 24% lower than the increases found in the occasional-use group. Researchers say that reduction is equivalent to preventing one precancerous growth per person over the four-year study.
The findings appear in the April issue of the Archives of Dermatology.
But researcher Steven Darlington and colleagues from the Queensland Institute of Medical Research in Australia say their study may actually have underestimated the protective effects of sunscreen in preventing skin cancer because it didn’t compare daily sunscreen use to not using sunscreen at all. Due to the well-known risks of skin cancer in a subtropical environment such as Australia, researchers opted to allow their comparison group to use sunscreen as they would normally.
Dermatologist Arielle Kauvar, MD, says these findings are encouraging because the protective effects of sunscreen in reducing skin cancer risk were especially dramatic in people that were younger or tanned easily.
“That tells us if you start using sunscreen on a regular basis when you’re young or before you have any visible skin damage that it will have a better effect,” Kauvar tells WebMD. “But it also had an effect on people with preexisting damage.”

How to Make Sunscreen a Daily Habit

Kauvar says this study should give people one more reason to get into the habit of putting on sunscreen every morning.
“I think people are often deceived by hazy or cloudy days, but you are still getting UV [ultraviolet] exposure at that time,” says Kauvar, who is clinical associate professor of dermatology at New York University School of Medicine. “At the beach, people who wait 20-30 minutes before putting sunscreen on are already behind the eight ball.”
Kauvar says it takes about a half-hour for sunscreen to be absorbed completely into the skin and offer the best protection from the sun’s damaging UVA and UVB rays. UVB rays are five to 10 times more damaging during peak sun hours between 10 a.m. and 2 p.m., but UVA rays are constant throughout the day and can pass through glass, like a car or office window.
That’s why she says it’s important to apply a broad-spectrum sunscreen with an SPF of at least 15 every day. But if you’re going to be swimming, sweating, or participating in sports and unlikely to reapply sunscreen regularly, a higher SPF factor can provide more protection.
The SPF of a sunscreen tells you how many times your natural protection the product offers, which means you could be in the sun 15 times longer with a SPF 15 sunscreen than you could without any protection.
Kauvar offers these helpful hints when selecting and applying sunscreen:

• Foundations, face powders, or other types of makeup that contain sunscreen aren’t likely to offer as much SPF protection as indicated on the label because they aren’t applied thickly enough. You are more likely to get better protection by using a separate product like a moisturizer containing a high SPF.
• Men are more likely to develop sun-related skin cancers on their scalp, back of the neck, and the tops of their ears because they neglect to apply sunscreen in these areas when working or playing outdoors. Sunscreen sprays and sticks can be helpful in reaching these often forgotten areas.
• Both men and women are most likely to get sun-related skin cancers on their nose because it gets the most sun exposure, which makes it a prime target for sunscreen.
• If you experience skin irritation from using sunscreen, try one of the newer, chemical-free sunscreens containing zinc oxide or titanium dioxide. These new formulations reflect the sun’s damaging rays but don’t react with the skin. They can also safely be used around the eye without causing stinging if the product gets into the eye after sweating or swimming.

In an editorial that accompanies the study, John L. M. Hawk, MD, of St. Thomas’ Hospital in London, UK, says the results demonstrate once again the great value of sunscreen application, “when undertaken conscientiously and carefully, against the now extremely well documented ravages of sunlight in both the short and long term.”
In addition, the study also looked at whether daily beta-carotene supplements offered any protection in preventing skin cancer. Previous studies in animals have shown that this nutritional supplement reduced skin cancer in animals, but no protective effect in humans was found in this study.