Skin cancer and the sun

[Professor Yaffle]

I have come across arguments several times (possibly all from the same source) that increased exposure to the sun does not cause an increase in malignant melanomas. I read an article about the same thing recently and it reminded me to ask about it here:

Skin cancer statistics are used to scare, not educate. Almost all of the 84,000 skin "cancers" that appear each year are in fact benign: they don't spread or kill; their cancerous name is a historical misnomer. Of course, sun exposure increases facial wrinkling, as does smoking, but the black ace in the fear game is melanoma, because the real thing is vicious.

As the article tells us, Cancer Research UK say the incidence of malignant melanoma has "quadrupled in Britain in the last 30 years". But if this were so we would have seen coffin-loads of consequences by now. We haven't, and in a recently published large UK study (British Journal of Dermatology, 2009), I and my colleagues showed that the reason mortality has not increased with incidence is that the tumours reported are actually benign; they are not true malignant melanomas. Our explanation of the phoney melanoma epidemic is "diagnostic drift which classifies benign lesions as … melanoma", a misdiagnosis "driven by defensive medicine, an unsurprising response to its commercialisation".

<snip>

http://www.guardian.co.uk/commentisfree/2010/jul/21/melanoma-myth-skin-cancer-sun

Has anyone here looked into this before? Is this guy (he's a professor of dermatology) a lone crank in the field using dodgy arguments/methodology, or does he have a valid case?

ETA: Here's a piece from him in the BMJ:
http://www.bmj.com/cgi/content/full/337/jul22_2/a764

 

[Professor Yaffle]

Bump

Anyone?

 

[casebro]

Dunno from false diagnoses, but I do read that all the Sun Block has not lowered skin cancer rates. Maybe the false diagnoses are driving up the numbers while the SPF is lowering actual cases?

There is always room for skepticism when the bean counters have a vested interest in counting more beans...

 

[Arrow]

I finished reading Dr Holick's book The Vitamin D Solution last week. He is probably the top researcher into vitamin D. He is also a former professor of dermatology at Boston University Medical center. That is what he mentioned in his book, that malignant melanomas were not linked to increased, moderate sun exposure. Basically he said maligant melanomas occurred more often in areas of the body not typically exposed to sun UV rays. Avoid becoming sun burnt he added as that can lead to problems too.

A good review of Dr Holick's book can be read at:

http://www.proteinpower.com/drmike/supplements/sunshine-superman/

 

[Ivor the Engineer]

Interesting. I like to read the rapid responses to such articles in the BMJ. Here's the other side of the argument and here are the rapid responses to the debate.

 

[MatildaGage]

Almost all of the 84,000 skin "cancers" that appear each year are in fact benign: they don't spread or kill; their cancerous name is a historical misnomer.

The author posted a retraction of that on 28 July 2008 in the rapid responses.

He deletes the "benign naevi" remark.

The quote in the OP implies only melanoma is of concern. All skin cancers are of concern & potentially deadly if they are not treated, though some are very slow growing, according to my dermatologist.

 

[lionking]

If skin cancer is not related to exposure to the sun, why are rates so high in Australia? http://www.actcancer.org/sun-smart/skin-cancer.aspx

Australia has one of the highest rates of skin cancer in the world. This is due largely to our climate, the fact that many of us have fair skin that isn’t suited to such harsh conditions, our proximity to the equator and of course our social attitudes and love for the great outdoors. Each year over 1700 Australians will die from skin cancer

My father-in-law, a farmer, had his skin cancer caught just in time. He could well have died.

 

[Arrow]

If skin cancer is not related to exposure to the sun, why are rates so high in Australia? http://www.actcancer.org/sun-smart/skin-cancer.aspx



My father-in-law, a farmer, had his skin cancer caught just in time. He could well have died.

Cancer isn't anything to take lightly, but doctors have known for awhile that nonmelanoma skin cancer is related to sun exposure. It can be fatal but rarely is.

 

[a3sigma]

A solar physicist friend of mine likes to point out that most people, if they stood close enough to a hydrogen bomb blast to redden their skin from radiation burns, would consider that something pretty alarming had happened to them. Yet, millions of them do just that, deliberately, every summer's day.

 

[Towlie]

...our proximity to the equator...

Melbourne is about as close to the Equator as San Francisco.

 

[rjh01]

A solar physicist friend of mine likes to point out that most people, if they stood close enough to a hydrogen bomb blast to redden their skin from radiation burns, would consider that something pretty alarming had happened to them. Yet, millions of them do just that, deliberately, every summer's day.

They would be burnt from different wavelengths of the EM spectrum.

 

[bobdroege7]

Melbourne is about as close to the Equator as San Francisco.

And Melbourne is as close to Darwin as you are to Maine.

Your grasp of geography needs a little work.

 

[rjh01]

Melbourne is about as close to the Equator as San Francisco.

I just checked. This statement is true.

 

[aggle-rithm]

Cancer isn't anything to take lightly, but doctors have known for awhile that nonmelanoma skin cancer is related to sun exposure. It can be fatal but rarely is.

My dermatologist doesn't even refer to my skin cancers as cancer; he calls it "sun damage".

 

[Schrodinger's Cat]

Well I can give you the information I have from working here at the Dana Farber Cancer Institute.

Melanoma is in fact very dangerous. It is actually cancer. That's the bad news.

The good news! If caught early, it has a virtually 100% cure rate. Melanoma in situ is the earliest stage, and it means the cancer is restricted to the area where you can see it, on the surface of the skin. Melanoma in situ is usually easily excized from the patient's skin. Often patients will have recurrent melanomas, the doctor will just keep slicing them off, and the patient is perfectly fine afterwards.

However, left untreated, Melanoma is very dangerous. At stage III it has spread to the lymph nodes. By stage IV, survival rate is around 10-15%.


The thing with cancer is so much depends on how long it takes before it is diagnosed. With many cancers, by the time the patient becomes symptomatic and realizes anything is wrong, the cancer is so advanced that survival rates have plummeted. The good thing about skin cancer is that, unlike, say, pancreatic cancer, you don't have to wait until you become symptomatic. You can SEE the cancer on your skin, and have it taken care of.

That is why it is so important to have moles or unusual spots on the skin checked up on, so if they become cancerous, you can slice that bugger off before it causes you any real damage.

 

[zooterkin]

I just checked. This statement is true.

Who said it wasn't?

 

[Towlie]

And Melbourne is as close to Darwin as you are to Maine.

Your grasp of geography needs a little work.

Actually, no, it's not; you're off by a few hundred miles, but thanks for the gratuitous abuse.

 

[Professor Yaffle]

The author posted a retraction of that on 28 July 2008 in the rapid responses.

He deletes the "benign naevi" remark.

The quote in the OP implies only melanoma is of concern. All skin cancers are of concern & potentially deadly if they are not treated, though some are very slow growing, according to my dermatologist.

The bit I quoted was from an article from July 2010.

I'm going to read up a bit more on this and come back when I have some more time (may be a while) and argue as if I accept he is correct, and see how his individual arguments hold up.

 

[aggle-rithm]

If skin cancer is not related to exposure to the sun, why are rates so high in Australia? http://www.actcancer.org/sun-smart/skin-cancer.aspx

I remember reading a while back that skin cancer is often linked to lymphoma. At the time it had just been discovered that, not only were people who were prone to skin cancer also prone to lymphoma, but people who spent more time in the sun got lymphomas more often.

 

[aggle-rithm]

I started getting skin cancers in my early thirties -- basal cell carcinoma. However, as I get older, the basal cell cancers are giving way to squamous cell carcinoma.

In her book "Another Day in the Frontal Lobe", Katrina Firlik described a patient who had a squamous cell cancer on his face. He was homeless and didn't get any medical attention. When the cancer became infected and disfigured his face, he wrapped a cloth around it. Years later, when a police officer finally noticed how bad off he was, the poor guy was finally taken to the hospital. The cancer and infection had destroyed one eye, eaten through his skull, and exposed his brain, which was being happily munched upon by maggots.

Dr. Firlik said when she examined the patient it was the only time in her career that she wanted to throw up.

So...not melanoma, but it shows the extremes of what untreated skin cancer can do.