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Most types of cancer not due to “bad luck” [pdf]

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Re: Most types of cancer not due to “bad luck” [pdf]

#61
post #50
post #46

Earlier quoted context omitted.

I put the full paper in pastebin: http://pastebin.com/GH1ZY8Zx Didnt read it, so not sure if its sufficiently understandable without the figures. Prob not.

What's HN's stance on posting a paywalled article to pastebin like this? If I were to guess, I'd think this to be frowned upon.

Why would you think that?

Re: Most types of cancer not due to “bad luck” [pdf]

#62
post #14

Earlier quoted context omitted.

The hallmark of science is predictive power. Experiments, replication, peer review are all nice but optional. When you have a general enough theory, you don't need to re-do the exact same experiment. You may not need to experiment at all and get by on mere observation. (Just call it a "natural experiment" when pressed.)

I don't think this is correct. Willingness to accept theories based on our limited understanding of the underlying facts and our observations has led to widespread, incorrect belief before. Descartes and Galileo accepted atomism because, based on their limited understanding of chemistry, it made sense. It wasn't until experiments like the cathode ray tube experiment and the gold foil experiment revealed more elementa…

No, because they predicted measurements that were wrong.

Re: Most types of cancer not due to “bad luck” [pdf]

#63
post #50
post #46

Earlier quoted context omitted.

I put the full paper in pastebin: http://pastebin.com/GH1ZY8Zx Didnt read it, so not sure if its sufficiently understandable without the figures. Prob not.

What's HN's stance on posting a paywalled article to pastebin like this? If I were to guess, I'd think this to be frowned upon.

I frown upon it because I prefer the PDF :P

Re: Most types of cancer not due to “bad luck” [pdf]

#64
post #38

Earlier quoted context omitted.

A specific critique raised in the press release from IARC is that the study has an "emphasis on very rare cancers (e.g. osteosarcoma, medulloblastoma) that together make only a small contribution to the total cancer burden." and that it "excludes [...] common cancers for which incidence differs substantially between populations and over time." So it sounds like the generalization hinted at in the abstract shows a big…

Yeah, we you look at total cancer burden and the associated epidemiology you can explain something like 90% of cancers from environmental sources (which includes things like obesity). Don't have a reference on me at the moment so feel free to disagree.

A 2005 Lancet paper [1] says that ~35% of cancer deaths can be attributable to a modifiable risk factor, and that's only risk factors likely to be causal, not known to be causal. If accurate, that would would support the "most cancer due to luck." However, this is the first that I've looked into it, and if it's higher than 50% I would be quite interested to see data supporting that.

[1] Abstract: http://www.thelancet.com/journals/lancet/article/PIIS0140-67... PDF: http://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(...

Re: Most types of cancer not due to “bad luck” [pdf]

#65
post #29

Earlier quoted context omitted.

> That, in itself, is a fascinating scientific result There are plenty of problems with the original paper see http://www.sciencemag.org/content/347/6219/224.full http://arxiv.org/abs/1501.04605 http://www.iarc.fr/en/media-centre/pr/2015/pdfs/pr231_E.pdf

Thanks for these links. The Science link is basically a retraction from the journalist who wrote the original summary article. She quotes the study authors making excuses about not having enough time to explain the subtleties under press deadlines. I've never read anything quite like it. It seems everyone agrees that Figure 1 of the Vogelstein paper, showing the striking correlation between Log(cancer incidence) and…

>The Science link is basically a retraction from the journalist who wrote the original summary article. She quotes the study authors making excuses about not having enough time to explain the subtleties under press deadlines. I've never read anything quite like it.

I don't agree with that characterization of the Science news article at all. It's a summary of the secondary reaction to the press coverage, but I can't construe it as a retraction of the original news coverage. For example, here's what David Spiegelhalter says in it, who's entire research lately has been on accurately communicating risk:

>In this case, he felt, “the gist of the coverage is very reasonable—most cases of cancer are due to chance.”

I too feel that the coverage was quite accurate, perhaps the most accurate that I've seen of a science tidbit in quite some time. If one's entire research program is on how to minimize environmental causes of cancer, I can see how it would feel like one's research was being minimized entirely, and require a vigorous defense. However, these "defenses", in particular Aaron Meyer's, seem to be fact free. In contrast, the epidemiology world seems to agree almost exactly with the Vogelstein paper's estimate of 65% chance, 35% modifiable causes (though perhaps somewhat by chance, as their measurements are not exactly of the same thing):

http://www.thelancet.com/journals/lancet/article/PIIS0140-67...

If there's broadly accepted epidemiological data that contradicts the molecular approach from Vogelstein, I would love to see it.

Re: Most types of cancer not due to “bad luck” [pdf]

#66
post #50

Earlier quoted context omitted.

What's HN's stance on posting a paywalled article to pastebin like this? If I were to guess, I'd think this to be frowned upon.

I frown upon it because I prefer the PDF :P

Here you go: http://www.uvm.edu/~cdanfort/csc-reading-group/tomasetti-sci...

Re: Most types of cancer not due to “bad luck” [pdf]

#67
The variation among geographic locations is interesting. On the other hand the rise in the rate of colorectal cancer in Japan may simply be due to a rise in cancer screening. Do Japanese die more often from colorectal cancers? For an example of why this is relevant, over 80% of men in their eighties may have prostate cancer yet the lifetime risk of dying from it is only 3% for a 50 year old man in the US (see http://ije.oxfordjournals.org/content/36/2/278.full ). So if we improve screening of prostate cancer we may find a lot more cases even though men's risk of dying from it is unchanged.

Re: Most types of cancer not due to “bad luck” [pdf]

#68
post #67

The variation among geographic locations is interesting. On the other hand the rise in the rate of colorectal cancer in Japan may simply be due to a rise in cancer screening. Do Japanese die more often from colorectal cancers? For an example of why this is relevant, over 80% of men in their eighties may have prostate cancer yet the lifetime risk of dying from it is only 3% for a 50 year old man in the US (see http://…

"A recent autopsy study reported on 314 African American and 211 Caucasian (sic) men aged 20–80 years who died of trauma in Detroit, USA. Microscopic evaluation in each case was based on 10–14 whole-mount step sections that were 2–3 mm thick.4 This study demonstrated a high prevalence of prostate cancer that increased progressively with advancing age and was similar at all ages in African American compared with Caucasian men (around 10%, 30%, 40%, 45%, 70% and 80% in the 3rd, 4th, 5th, 6th, 7th and 8th decades, respectively). When this ubiquity of microscopic prostate cancer is placed in the context of lifetime risks of clinical or fatal prostate cancer (about 10% and 3%, respectively for a man aged 50 years in the USA),5 these data indicate that local or distal progression of early cancer is far from inevitable within a man's lifetime. Put another way, only a minority of prostate tumours are highly aggressive and life-threatening, while the majority are slow-growing and indolent."

Re: Most types of cancer not due to “bad luck” [pdf]

#69

Earlier quoted context omitted.

Thanks for these links. The Science link is basically a retraction from the journalist who wrote the original summary article. She quotes the study authors making excuses about not having enough time to explain the subtleties under press deadlines. I've never read anything quite like it. It seems everyone agrees that Figure 1 of the Vogelstein paper, showing the striking correlation between Log(cancer incidence) and…

>The Science link is basically a retraction from the journalist who wrote the original summary article. She quotes the study authors making excuses about not having enough time to explain the subtleties under press deadlines. I've never read anything quite like it. I don't agree with that characterization of the Science news article at all. It's a summary of the secondary reaction to the press coverage, but I can't c…

>I don't agree with that characterization of the Science news article at all.

Here's the section of the news article that I feel reads like the journalist walking back the central claim in her original news article. It also seemed to me that she was attempting to pin the blame for the misunderstanding on Tomasetti (by quoting from her initial interview with him, and reporting that he had vetted her initial piece):

"...[W]as the “two-thirds” figure actually referring to a fraction of cancer cases? Tomasetti had explained to Science that “if you go to the American Cancer Society website and you check what are the causes of cancer, you will find a list of either inherited or environmental things. We are saying two-thirds is neither of them.” He also confirmed the news story's language describing the study before it was published. In a follow-up interview [...] Tomasetti clarified that the study argued that bad luck explained two-thirds of the variation in cancer rates in different tissues—a subtly different claim.

Despite the confusion among reporters, Tomasetti did not feel they had been careless[...] And, he believes, he did his best to convey his findings to nonexperts. “If given enough time, or space, I can explain the subtleties of any given scientific result to anyone really,” but there were only so many hours he could spend speaking with reporters on deadline. The material is complicated even for statistical gurus, he believes. He has been busy preparing a technical report with additional details, and Johns Hopkins also sent a follow-up explainer to journalists and posted it online."

Here's a pastebin of the article in case others are interested in it: http://pastebin.com/upWV95PK

I don't agree at all with your contention that the criticisms of the original paper are 'fact-free' and based on researchers feeling threatened. There are lots of problems with this paper; the fact that their conclusions may agree with data from other fields (or may even be right) doesn't change that.

Re: Most types of cancer not due to “bad luck” [pdf]

#70
post #28

Physician here. I think I can provide some clarification for what is going on here. I just read the article the WHO is addressing and this is a line from the final paragraph: Our analysis shows that stochastic effects associated with DNA replication contribute in a substantial way to human cancer incidence in the United States. First, the terminology is important to understand. In medicine, "stochastic" is in contras…

This is the key point. Tomasetti and Vogelstein (2015) arguably demonstrated that most types of cancer are primarily stochastic. But it's the primarily deterministic types of cancer that account for most morbidity and mortality.
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