Medical Cancer man-made or junk science?

[Siv]

"Younger adults and men of any age are less likely to protect themselves from the sun. However, females seek shade far less than males. Adults with incomes below 200 percent of the poverty level are less likely to use sunscreen. Young adult women are most likely to get too much exposure to artificial light through indoor tanning." (The National Cancer Institute, Cancer Trends Progress Report 2009-10, Sun Protection - Groups at High Risk for Getting Too Much Sun. http://progressreport.cancer.gov/doc_detail.asp?pid=1&did=2007&chid=71&coid=711&mid=#target )

Well, I enjoyed reading the entire progress report. I think I will leave this topic now since I have contributed on page 2 and 3.

Brief mention, I have lived my entire life in areas where the sun shines most of the year. I love the beach and always put on my sunscreen. Even on an overcast day you can still get burned. Matter of fact, I always use everyday my Neutrogena, Ultra Sheer (Dry-Touch) Sunblock (SPF 70) on my face and on the top of my hands. OK, call me vain! I'm a woman, and I want to look pretty forever! No wrinkles yet or brown spots. And I'm over 50 but people tell me I look like I'm in my late 30's.

This sun avoidance mania has, apart from benefitting sunscreen manufacturers, only served to cause a worldwide epidemic of Vitamin D deficiency.

If your Vitamin D status is corrected, you don't burn as easily. If your Vitamin D status is very low, you do.

The skin cancer and sun link is also being questioned now.

 

[ViewsofMars]

This sun avoidance mania has, apart from benefitting sunscreen manufacturers, only served to cause a worldwide epidemic of Vitamin D deficiency.

I doubt that. From the Office of Dietary Supplements - National Institutes of Health:

Despite the importance of the sun to vitamin D synthesis, it is prudent to limit exposure of skin to sunlight [36] and UV radiation from tanning beds [37]. UV radiation is a carcinogen responsible for most of the estimated 1.5 million skin cancers and the 8,000 deaths due to metastatic melanoma that occur annually in the United States [36]. Lifetime cumulative UV damage to skin is also largely responsible for some age-associated dryness and other cosmetic changes. It is not known whether a desirable level of regular sun exposure exists that imposes no (or minimal) risk of skin cancer over time. The American Academy of Dermatology advises that photoprotective measures be taken, including the use of sunscreen, whenever one is exposed to the sun.
http://ods.od.nih.gov/factsheets/vitamind.asp#h3

If your Vitamin D status is corrected, you don't burn as easily. If your Vitamin D status is very low, you do.

When your skin is exposed for a length of time, you burn in the sun if you don't wear sunscreen . I take a daily multi-vitamin and adhere to the dietary Guidelines from the Dietary Supplement Fact Sheet: Vitamin D :

The Dietary Guidelines for Americans describes a healthy diet as one that
Emphasizes a variety of fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.

Milk is fortified with vitamin D, as are many ready-to-eat cereals and a few brands of yogurt and orange juice. Cheese naturally contains small amounts of vitamin D. [I love milk, yogurt, and orange juice. I had Oat Bran Muesli mixed with yogurt and a sliced fresh peach. Yummy!]

Includes lean meats, poultry, fish, beans, eggs, and nuts.

Fish such as salmon, tuna, and mackerel are very good sources of vitamin D. Small amounts of vitamin D are also found in beef liver and egg yolks.

Is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.

Vitamin D is added to some margarines.
Stays within your daily calorie needs.
http://ods.od.nih.gov/factsheets/vitamind.asp#h3

The skin cancer and sun link is also being questioned now.

How so? Give me a quote and the link (url) that supports your claim.

 

[Ygggdrasil]

I'm a firm believer cancer is definatly man made. I don't have evidence, I don't have anything, its my personal opinion. The amount of crap in foods, drinks, cigarettes, air pollution, the way we are... It does not take a genious to work out...

P.S - Remember that's just my opinion.

There are definitely things in the natural environment that cause cancer, however. UV radiation causes skin cancer. Human papiloma virus causes almost all forms of cervical cancer. Aflatoxin, one of the most carcinogenic substances known, is naturally produced by a species of fungus. Naturally occurring radon gas from the soil can cause lung cancer. The list goes on and on. None of these sources of cancer are man made (although one could argue that human depletion of ozone has contributed to skin cancer).

The real question is what fraction of cancers in our society are attributable to "man-made" causes (modern lifestyle choices and pollution) and what fraction are attributable to "natural" causes (aging, natural sources, etc.). While much research has been done on this subject, I do not think the analysis done by David and Zimmerman adds much of substance to the debate.

 

[ViewsofMars]

There are definitely things in the natural environment that cause cancer, however. UV radiation causes skin cancer. Human papiloma virus causes almost all forms of cervical cancer. Aflatoxin, one of the most carcinogenic substances known, is naturally produced by a species of fungus. Naturally occurring radon gas from the soil can cause lung cancer. The list goes on and on. None of these sources of cancer are man made (although one could argue that human depletion of ozone has contributed to skin cancer).

The real question is what fraction of cancers in our society are attributable to "man-made" causes (modern lifestyle choices and pollution) and what fraction are attributable to "natural" causes (aging, natural sources, etc.). While much research has been done on this subject, I do not think the analysis done by David and Zimmerman adds much of substance to the debate.

The problem that I have noticed is people don't READ! The OP presented an MSN article that had a lot of media hype, whereas I previously presented peer-viewed journals. You can also review my post #28 and take note of what is considered to be "man-made" causes. I hope you can figure it out. Also, lead paint can cause cancer. Very old homes have it. People invented (made) that paint.

A good example of a "man-made" cause of cancer are people who ignore what professionals have warned them about cancer and how he/she could avoid it. Smoking cigerates can cause cancer. People still smoke and die because of it. People make cigerates and people choose to smoke, knowing they could die from it. Basically, sad to say, a person kills him or her self.

 

[Evo]

While the authors ask an interesting and important question, the question is also extremely difficult to answer due to the low quality of evidence available and relative lack of knowledge about these societies. Thus, it is not surprising that the authors arguments are fairly weak and lack scientific rigor. For example, they state that cancer is rare in ancient society. Well, how rare is rare? Bone cancer is also rare. The authors' case would have been greatly strengthened had they provided some quantitative analysis. A case study of the incidence of bone cancer in skeletal remains could have been a nice area to study. The authors state that "tens of thousands of skeletons have been examined but only a few diagnoses of possible and/or probable malignancies — based on gross appearance and occasional X-ray scans showing defects in or masses on bones — have been made." Here, it would have been nice to compare the number of possible/probable cases of cancer with the number of cases expected if the rate of cancer in these ancient societies were the same as in modern societies. If the rate of cancer in ancient societies is drastically lower than the rate of cancer in modern society, then a crude calculation like this would have been illuminating. Furthermore, excluding the effects of the lower life expectancy of ancient societies is another argument that requires some quantification to gauge the magnitude of the effect versus the observed decreased incidence in the rate of cancer. Unfortunately such quantitative analyses are difficult due to the lack of knowledge about these societies.

In a broader context, the authors' conclusion does make sense. We know that many cancers are caused by lifestyle choices that would be less prevalent in ancient societies (for example, some estimate that tobacco use causes 30% of cancers and obesity causes 20% of cancers, two factors unlikely to be present in ancient Greece and Egypt). However, just because the conclusion make sense does not mean it is well supported by the available evidence.

Thanks for finding this. Her statement that "there is nothing in nature that can cause cancer." is so wrong. They've lost all credibility for me.

 

[ViewsofMars]

In their Nature Cancer Reviews article, David and Zimmerman examine ancient societies to determine the prevalence of cancer in ancient societies. They find that cancer is rare in the ancient societies that they studied and, after considering various possible explanations for the relative lack of ancient tumors, suggest that their findings provide evidence that cancers are caused primarily by factors of modern society such as smoking and pollution.

I presented this earlier :

Nature Reviews Cancer 10, 728-733 (October 2010) | doi:10.1038/nrc2914

Cancer: an old disease, a new disease or something in between?
A. Rosalie David & Michael R. Zimmerman

Abstract
In industrialized societies, cancer is second only to cardiovascular disease as a cause of death. The history of this disorder has the potential to improve our understanding of disease prevention, aetiology, pathogenesis and treatment. A striking rarity of malignancies in ancient physical remains might indicate that cancer was rare in antiquity, and so poses questions about the role of carcinogenic environmental factors in modern societies. Although the rarity of cancer in antiquity remains undisputed, the first published histological diagnosis of cancer in an Egyptian mummy demonstrates that new evidence is still forthcoming.
http://www.nature.com/nrc/journal/v10/n10/full/nrc2914.html

I would like to make it clear that "new evidence is still forthcoming". Ygggdrasil, I would like a link (url) and the statement the authors made that prompted this remark of yours, "suggest that their findings provide evidence that cancers are caused primarily by factors of modern society such as smoking and pollution." Basically, give me a quote and the link (url) that supports your claim.

Thanks for finding this. Her statement that "there is nothing in nature that can cause cancer." is so wrong. They've lost all credibility for me.

Evo, my post #26 needs to be reviewed again. I think you have to read the entire document to get the jest of what she meant. I wouldn't like to quote-mine from the article. I'll present the link once again to this message of mine.
http://www.manchester.ac.uk/aboutus/news/display/?id=6243

Personally, I'm not fond of knocking down reputable scientists in public forums. Often times, it sends a message out to individuals that scientists can't be trusted or lie. I do think Rosalie David & Michael R. Zimmerman are reputable scientists since there article did appear in Nature, which is peer-reviewed journal.

I'll make it very clear that the reason why I joined PhysicsForums was to support the scientific community. Thank you.

 

[Evo]

I'll make it very clear that the reason why I joined PhysicsForums was to support the scientific community. Thank you.

I also fully support science, but unless the statements they made (that I pointed out) in the Nature article are blatant misquotes, I can't support it. People need to know that there is a difference between good and bad science.

 

[Evo]

Claims that cancer is only a "modern, man-made disease' are false and misleading.

We were concerned to see headlines in the media today claiming that scientists say cancer is ‘purely man-made’. This is not only scientifically incorrect, but misleading to the public and cancer patients.

Our lifestyles have a great impact on our chances of developing cancer – as we’ve said many times. But the evidence that’s being used to justify these latest headlines doesn’t in any way support the assertion that cancer is modern or man-made.

The source of the story

The story is based on this press release publicising an opinion piece in the scientific journal Nature Reviews Cancer by Professor Rosalie David and Professor Michael Zimmerman.

According to the press release, the paper was presented at a conference

http://scienceblog.cancerresearchuk...n-man-made-disease’-are-false-and-misleading/

 

[Ygggdrasil]

I presented this earlier

Yes, this review paper from Nature Reviews Cancer is the one referenced by the MSN article in the opening post and the one I discussed in my earlier post. I read through the entire paper and, in my post #36, I summarized the authors' arguments and offered my own scientific critique of their arguments.

I would like to make it clear that "new evidence is still forthcoming". Ygggdrasil, I would like a link (url) and the statement the authors made that prompted this remark of yours, "suggest that their findings provide evidence that cancers are caused primarily by factors of modern society such as smoking and pollution." Basically, give me a quote and the link (url) that supports your claim.

Sure. Here is a direct quote from paragraph 18 of the Nat. Rev. Cancer review paper:

"Although the palaeopathological diagnosis of cancer is subject to many difficulties, we propose that the minimal diagnostic evidence for cancer in ancient remains indicates the rarity of the disease in antiquity. Carcinogenic environmental factors have been linked to up to 75% of human cancer, and the rarity of cancer in antiquity suggests that such factors are limited to societies that are affected by modern lifestyle issues such as tobacco use and pollution resulting from industrialization."​

The link is http://www.nature.com/nrc/journal/v10/n10/full/nrc2914.html although you need a subscription to the journal in order to be able to read the full article.

Evo, my post #26 needs to be reviewed again. I think you have to read the entire document to get the jest of what she meant. I wouldn't like to quote-mine from the article. I'll present the link once again to this message of mine.
http://www.manchester.ac.uk/aboutus/news/display/?id=6243

I agree, reading the full Nature Reviews Cancer article is necessary to understand the authors' arguments. Reading the full article let's you appreciate the fact that while David tells the popular press that "there is nothing in the natural environment that can cause cancer," such statements are absent from her peer-reviewed paper. Instead, the authors state their case much more cautiously. From the concluding paragraph:

"Despite the fact that other explanations, such as inadequate techniques of disease diagnosis, cannot be ruled out, the rarity of malignancies in antiquity is strongly suggested by the available palaeopathological and literary evidence. This might be related to the prevalence of carcinogens in modern societies."​

Personally, I'm not fond of knocking down reputable scientists in public forums. Often times, it sends a message out to individuals that scientists can't be trusted or lie. I do think Rosalie David & Michael R. Zimmerman are reputable scientists since there article did appear in Nature, which is peer-reviewed journal.

I'll make it very clear that the reason why I joined PhysicsForums was to support the scientific community. Thank you.

A small correction, the article did not appear in Nature, but in Nature Reviews Cancer, a journal published by the Nature Publishing Group. While still a prestigious, peer-reviewed journal, Nat. Rev. Cancer is nowhere near as prestigious as Nature.

Although overall the peer-reviewed scientific literature is fairly trustworthy, there are many cases where scientists overinterpret their data and make faulty conclusions. I believe this is the case with David and Zimmerman's Nat. Rev. Cancer article. From the data and arguments they present in their article, I do not believe that we can make any solid conclusions about the prevalence of cancer in ancient societies. Furthermore, if the goal is to argue that most cancers are from man-made sources, there are much more productive avenues of research to address this question.

Science advances because scientists are willing to question and criticize others ideas. Therefore, well reasoned, evidence-based criticism of published and unpublished science is a great way to support the advancement of science.

 

[bobze]

Good post Yggg.

ViewsofMars--I applaud your effort to support the scientific community, but please remember that scientists are people too and are also prone to excitement and exaggeration of their conclusions (especially in press conferences) as any "layman".

After sitting down and reading the paper there are many problems I see in it as well. You should really read Yggg's critique of it. In science we're not taught to accept something because "its published in a peer-reviewed" journal, one should read all journals with a sense of healthy skepticism. Critical thinking and skepticism are required even for "published" material. Something doesn't enter the realm of dogma simply because someone was able to get it published.

For instance in the article they authors claim;

Osteosarcoma is not currently an exceptionally rare tumour and, as it usually produces bone, one might expect to encounter it more frequently in archaeological material than is the case, especially as this is a tumour associated with young people. Bone is notorious for trapping radioactive minerals, and one can speculate about the role of radiation in our modern world in causing bone tumours.

Not exceptionally rare? The office of rare diseases over at NIH lists the prevalence as affecting less than 200,000 Americans. Or less than 0.06% of the US population. That's pretty exceptionally rare in my opinion.

Much of their conclusions are based on excerpts like this;

Gray specifically noted the total absence of any radiological evidence of malignancy in his survey of 133 mummies.

Extremely small sample sizes, biases (yes, they have a clear case of http://en.wikipedia.org/wiki/Selection_bias" (I'd like to give them the benefit of the doubt, that this wasn't their motivation for not doing statistical tests) make this paper's scientific value about worth its weight in paper.

Also I'd draw you attention to this being published under: Perspectives>Science and society. While this is still "peer-reviewed" this isn't primary research, its a glorified Op-Ed.

I think the problem is;

1. The media will pick up anything "published" in a "peer-reviewed" journal and run with it, especially when its an "something causes cancer" or "something 'cures' cancer" type.
2. People shouldn't use the media as a source for their "scientific literacy", you're getting filtered and biased information.
3. Many people aren't familiar with how scientific publication works (sure you learn about peer-review in school, but you don't delve into differences in "Op-Ed" type papers and primary research).

 

[Dr Lots-o'watts]

"Is the common nature of cancer worldwide purely a man-made phenomenon?"

The cancer-causing agents have always been there. Cancer happens when man meets the agent.

No unprotected organism lives in the scorching desert sun, no organism lives inside mineral and radioactive rocks, and no organism feed on burnt matter. But we humans, we go right at it. Man doesn't "make" the agents, man dives into them. That's the phenomenon.

 

[turbo]

Thanks for finding this. Her statement that "there is nothing in nature that can cause cancer." is so wrong. They've lost all credibility for me.

I would have to take exception to that sweeping claim, too. Years ago, I visited a rock and gem shop in Western Maine, and was chatting with the owners. A week or so before, a customer wanted to try out a geiger counter hands-on before buying, and he was wandering about the shop looking at the readings when the probe was in proximity to some minerals that tend to be somewhat radioactive. Suddenly, the count shot up and the meter was blipping like crazy. The owners and the customer tried to find out what was causing the spike, and discovered that a newly-excavated large smoky quartz crystal they had recently bought from a prospector was really hot (in the radioactive sense). If radiation can be implicated in the causation of cancers, it should be evident that natural sources of radiation need to be considered.

Of course, if you live around here and have quartz/granite underlying your prospective house, you would be well-advised to have a Radon screening preformed before buying it, so you can find out if the levels are safe or at least can be remediated.

 

[Evo]

Wow, could this thread be any more off topic? It was about cancer in mummies.

 

[Proton Soup]

Wow, could this thread be any more off topic? It was about cancer in mummies.

sorry. but i did do my best initially by referencing Galen.

 

[Evo]

I have spilt off the posts discussing various foods and health related issues.

The discussion has been moved here - https://www.physicsforums.com/showthread.php?t=441543

Only posts concerning the article on mummies in the OP will be allowed in this thread.