Risk of common skin cancer increased by as much as 90 per cent with sunbeds, study finds

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Published: 11 Sep 2014
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Patrick Tierney - University of Dundee, Dundee, UK

PhD student, Patrick Tierney, talks to ecancertv at the XV World Congress on Cancers of the Skin in Edinburgh, UK about the collaborative research between the University of Dundee, UK, and Leiden University Medical Centre, Netherlands, which has looked at the significant impact that sunbeds have upon incidences of squamous cell carcinoma.

Read the article for more.

I’m dealing with sunbeds, artificial tanning units. The rise in skin cancer, for most people the main source of UV radiation is the sun, however, with artificial tanning units you’re getting UV radiation which has been classified as a carcinogen by the IARC.

Have you looked at this before in previous research?

Previously, in 2010, I was part of a nationwide study in England to collate the data from the emission of sunbeds. So we collected the spectral irradiance which we were able to add the [??] - which is basically the biological effectiveness from the UV. In sunbeds you’ve got a UVA and UVB component with the UVA component being the longer wavelength. So from this we were able to work out the spectral irradiance and then put that in terms of erythemal irradiance. So the scientific community in consumer products has a guideline of 0.3 irradiance W/m2,however our findings were that they’re actually coming in at a mean of over 400 sunbeds of 0.56 W/m2. So that’s nearly double the guidelines that are out there.

What did your more recent study entail?

We worked closely with the Office of National Statistics to find what kind of holidays people take so we took it as the amount of days people take abroad. So we took, say, an average of 10.5 days abroad so it’s a bit less than two weeks but that works out to be 85 SED based on dosimetry studies done in the past; SED is standard erythemal dose, it’s 100J/m2. We had this great data set on over 400 sunbeds so it’s the largest European comprehensive study taken. So we then worked closely with Leiden University which has done previously studies with squamous cell carcinoma, keratin coenocyte cancer a non-melanoma unlike melanoma but this stems from chronic exposure to UV radiation. So working then with Leiden University, we were able to use their tumour model they did work on induction and tumours on albino mice, we were able to work out an algorithm which is basically down to two most important factors, it’s your age and then your dose. Then from parameters, power parameters from epidemiological studies, we were able to add this in to our model.

What we really discovered then is what’s an age risk that you’d be most likely to look at. So we said you wouldn’t really have exposure for an infant so we said holiday exposure from five years onwards and we said we’ll give it a 15 year period, starting at age 20 up to 35, which is average sunbed use anyway in the population. We added this on into the model as well and also when you’re in a sunbed you’re not applying sunscreen, people are actually wanting to get irradiated by UV. So you’re getting your fill, about 85% excluding your trunks, where day to day you’re getting about 10%, 6% 4%. Then you’ve got your holidays, sunbeds and day to day so that adds extra risk on top of your baseline exposure.

Was there much difference between different sunbeds?

From our original study of 0.56 that was just a mean. There was quite a variation in sunbeds out there. Sunbeds range from 280-400nm and the UVB range is 280-315nm which causes direct damage with the longer wavelengths, 315-400nm, can penetrate further down into the epidermis and into the base layer which causes DNA damage to CPD  products. So we said we’ll be fair, we’ll look at different percentile outputs. So we looked at the 95th, the 5th and the 50th median outputs and put these into our sunbed model as well.

What did you find?

From that we were able to look at then the situation, this is just a normal office worker, they’re not getting much day to day but they might go on a sunbed. So we looked at them and said right, when you get to mid-age what’s the risk we’re looking at? So a 50% output then we got about 82 SED and then we were able to work out then mid-fifties you get a 40% increase. But then if you look at the medium levels you’re getting 176 SED per annum so then we looked at what’s the risk there – a 90% risk on top of your baseline dose or baseline situation. And then if you look at the higher end, 302 SED per annum, you’re looking at 180% risk by your mid-fifties with additional use of sunbeds.

What motivated this research?

In 2010 I went to NHS Tayside and an opportunity came up to work with CRUK to embark on a journey. In the past we did look into sunbeds in Scotland, we didn’t look at the newer version, high power output, of sunbeds, up to 250W. So these new fast tan sunbeds are out there but there’s very little data actually in England on this so we took part to find the largest comprehensive survey on sunbeds throughout England and the suburbs of London.

Are these “Fast Tan” sunbeds relatively new?

They started in the mid-2000s so they want faster tans, these stand-up beds, people go in in three minutes and they go out at night. But they’ve got a popularity just due to this quick tan tanned look and Made In Chelsea and all these kind of shows. But I think the spray-on tan maybe is the safer way.

What would your recommendations be in terms of sunbeds?

Obviously in the skin world people are going to say just stop then. So you have the likes of Brazil have stopped them, Australia are following suit as well. Well you could have licensing but you need people to enforce it and local governmental bodies and councils. I’ve worked with these in the past and they don’t have the funds to do this. At the end of the day you’re putting artificial UV light on you which we’ve discovered is 2-3 times the amount from Mediterranean noon sun from Greece. So it doesn’t make sense that northern kinds of skin types, especially Celtic skin types with red hair and freckles, you’re not built genetically to be put into an artificial unit, and sunbeds that’s going to be your Mediterranean sun.