Cancer man-made or junk science?

Evo

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

I presented this earlier :
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.


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/...splay/?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 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

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

http://scienceblog.cancerresearchuk....nd-misleading/

Ygggdrasil

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.

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/v1...l/nrc2914.html although you need a subscription to the journal in order to be able to read the full article.

I agree, reading the full Nature Reviews Cancer article is necessary to understand the authors' arguments. Reading the full article lets 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."

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;

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;

Extremely small sample sizes, biases (yes, they have a clear case of selection bias--I know that's a Wiki link, but if you aren't familiar with statistics and types of bias please read it for an intro), and lack of any kind of statistical analysis done in this study (as Yggg pointed out)--Coupled with what would be a terrible statistical power (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

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

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 - http://www.physicsforums.com/showthread.php?t=441543

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