Never underestimate the power of the sun! New research shows that not even a potent sunscreen is enough to protect you against cancer.

Almost half of Australian adults still have the misguided belief that a tan looks healthy. Are you one of them? Then chances are you think that applying sunscreen before venturing into the midday sun is all you need to protect you from the damaging effects of ultraviolet (UV) radiation.

Well, think again. The World Health Organisation (WHO) has now officially classed UV radiation as a human carcinogen. What’s more, researchers from the UK Institute of Cancer Research and the University of Manchester’s Cancer Research UK Institute have found that using sunscreen alone to limit excess exposure to UV light – identified as the most important modifiable risk factor for skin cancer – may not offer total protection.

Their research was published in the June 2014 issue of Nature.

UV targets protective genes
With more than 12 500 new cases of melanoma – the deadliest form of skin cancer – diagnosed in Australia every year, these findings are not to be taken lightly. Australia has the world’s highest incidence of melanoma, which causes 75% of all skin cancer deaths in the country.

The researchers discovered that exposure to UV light leads to abnormalities in a gene called p53, which usually works to prevent DNA damage from UV radiation.

Study author and scientist Prof Richard Marais of Cancer Research UK explained that UV light targets the very genes protecting us from its own damaging effects. “Even with sunscreen, radiation is still able to cause abnormalities in the p53 gene, just at a lower rate,” he commented.

Head of Health Information at Cancer Research UK, Dr Julie Sharp, remarked that while properly applied sunscreen can protect against UV radiation, people tend to “think they're invincible” once they’ve put it on, spending longer hours in the sun and increasing their overall exposure to UV light.

In her view, the study highlights that people should not only rely on sunscreen, but that they should also adopt other sensible sun safety habits.

Sunscreen still important
Importantly, this DOES NOT mean that you should skip the sunscreen this summer. On the contrary.

What it does indicate is that we should all take several measures – including the application of sunscreen – to protect ourselves from the sun’s harmful rays.

This research study follows on an earlier landmark randomised Australian trial – described as the “first of its kind evaluating sunscreen use against melanoma as an outcome”. The extensive study – by epidemiologist Professor Adele Green, Deputy Director of the Queensland Institute of Medical Research – involved 1 621 white Australian adults aged between 25 and 65, who were studied for more than a decade.

In the study published in the Journal of Clinical Oncology in 2011, Professor Green found that daily application of an SPF 16 sunscreen to the head, neck, arms and hands reduced melanoma incidence by half in study participants. Moreover, there was a 73% reduction in the more dangerous invasive types of melanoma among daily users vs. those using sunscreen less frequently, or not at all.

Professor Green noted the results were convincing enough to recommend daily sunscreen application, along with other standard sun-protection measures like avoiding the midday sun and using protective clothing.

What is melanoma and why it is dangerous?
Melanoma is a malignant cancer, found in the melanocytes of the skin’s outer epidermis layer, according to the Australia and New Zealand Melanoma Trials Group (ANZMTG). It explains that melanocytes are pigment cells that cause freckles and moles to appear on the skin. Melanocytes also produce the sought-after bronze skin colour that appears after sun exposure.

What is less well known is that melanoma can develop anywhere on the skin, including the eyes, soles of the feet, mucous membranes and nervous system.

Melanoma isn’t only cause for concern in Australia. Prof Green, one of the international presenters at the 15th World Congress on Cancers of the Skin, painted a grim global picture of skin cancer, commenting that uncontrolled and unrestricted use of sun beds in Europe and many American states has increased incidence and mortality rates of melanoma, especially among young women.

“One of the most dangerous myths is that tanning salons are safer than outdoor sun exposure,”sunsafe advocate Terry Slevin, Education and Research Director of Cancer Council Western Australia, says. He points out that tanning beds emit three to five times the intensity of midday summer sunlight.

Why take the risk?
One cannot help wondering why people still continue to ignore the health risks of UV exposure. Once again, research is starting to provide answers.

A study published in Cell in June 2014 suggested that chronic exposure to UV radiation causes the body to release “feel-good” endorphins, which may make sun exposure addictive.

Endorphins act through the same pathway as heroin and related drugs, which could explain why people have an instinctive desire to be in the sun despite its known health risks, noted senior study author David Fisher of Massachusetts General Hospital and Harvard Medical School.

sunscreen-simply-not-enough-melanomaMuch being done in Australia
Fortunately, much is being done to protect Australians against skin cancer.

Public health and educational Sunsmart campaigns, launched in Australia in the 1980s, have resulted in positive results in skin cancer prevention and promising shifts in attitudes and behaviours regarding UV exposure.

Australia introduced new regulations in November 2012 to change the maximum sun-protection factor (SPF) from 30+ to 50+, thereby providing more UVA protection and bringing it closer in line with similar regulations in Europe and Asia.

From 31 December 2014, Australia will become the second place in the world (after Brazil) to implement a total ban on commercial tanning beds – a move that’s been welcomed by researchers working tirelessly to curb the alarming incidence of melanoma.

Top melanoma prevention tips:

    • Avoid sunburn by minimising sun exposure, especially in the middle of the day when UV levels are most intense.

    • Download the free SunSmart app for iPhone, iPad and Android. This innovative app enables you to check the daily sun protection times for your location to make it easier to take sensible sun-protection measures. Go to Sun Smart Australia for more info.

    • You can also opt for the World UV app developed by the British Association of Dermatologists (BAD). The app provides free daily UV forecasts for over 10,000 locations worldwide and fine-tunes UV risk according to location and skin type. Visit www.bad.org.uk/sunawareness.

    • Seek shade or sun shelters (e.g. umbrellas, trees and buildings) when the sun is at its strongest, i.e. between 10am and 4pm. Don’t be fooled into thinking you can’t get sunburnt on cooler or overcast days.

    • Remember that UV radiation reflects off surfaces like water, sand and concrete, so you canstill burn even if you think you’re protected.

    • Wear a wide-brimmed hat that covers your face, head, neck and ears from the sun. Caps don’t provide adequate protection.

    • Wear sun-protective clothing (e.g. a long-sleeve shirt with closely woven fabric or with a UV rating) that covers the back of the neck, shoulders, arms and legs.

    • Remember to protect your eyes by wearing close-fitting, wraparound, UV-blocking sunglasses.

    • Regardless of your skin type, apply liberal amounts of 30+ broad spectrum sunscreen every day, and a water-resistant one with an SPF of 30+ for extended outdoor activity.

    • Apply two tablespoons of sunscreen to your whole body 20 minutes before going outside and reapply every two hours, or immediately after excessive sweating or doing water activities.

    • Never use tanning beds or tanning lamps.

    • • Examine your skin from top to bottom every month and see your doctor for a thorough skin exam every year.

    • • For more information, contact the Cancer Council on 13 11 20 (cost of a local call).



Sources:
- Richard Marais et al. Ultraviolet radiation accelerates BRAF-driven melanomagenesis by targeting TP53. Doi: 10.1038/nature13298, Nature, 11 June 2014.
- XV World on Cancers of the Skin. http://ecancer.org/conference/calendar/536-xv-world-congress-on-cancers-of-the-skin.php
- Melanoma Institute Australia. http://www.melanoma.org.au/
http://www.melanoma.org.au/about-melanoma/melanoma-skin-cancer-facts.html
- http://www.anzmtg.org/content.aspx?page=whatmelanomaWhat is Melanoma?
- http://www.cancer.org.au/about-cancer/types-of-cancer/skin-cancer/melanoma.html
- Caroline Chang, MD et al. Framing Health Matters: More Skin, More Sun, More Tan, More Melanoma. American Journal of Public Health November 2014, Vol 104, No. 11 2014.
- Professor Adele Green AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. J Clin Oncol. 2011; 29(3):257--- 263.
- http://www.australiaunlimited.com/science/showing-that-prevention-is-better-than-cure
- http://www.skincancer.org/prevention
- Skin b-Endorphin Mediates Addiction to UV Light, David Fisher et al., published in Cell, 19 June 2014.

Image via Thinkstock




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