Fate Causes Cancer
Aetiology is questioning the intelligence of Brits for the fact that “More than a quarter of [British] people believe that fate alone will determine whether they get cancer, not their lifestyle choices”.
Brits, here I come to the rescue–I agree. Fate causes cancer. (Aetiology’s Tara Smith is an assistant professor of epidemiology, which may have clouded her views on this one–that’s what statistics and population studies will do to you!)
If you look at groups of people, you can easily say that smoking increases your risk of many, many cancers. And other lifestyle choices definitely increase your risk of cancer. But look what I said–increased risk. Not guarantee. Not all smokers develop lung cancer, not all smokers develop emphysema. Not all obese people develop diabetes, and not all people who develop diabetes are obese.
You can say that X increases your risk of cancer by 99%, but when you go down to the individual level, that individual has to either develop cancer or NOT develop cancer. We can’t say which smokers will get cancer and which won’t, only that they’re more likely to. There’s still random chance–if you want to call it fate, so be it–that gives people cancer.
So there you are, Brits, you’re right.
If you want to reduce your risk of cancer, heart disease, and other big killers, prevention is the key, and lifestyle changes can do a lot. But we want to accurate for the individual, we don’t know who will get cancer. Is this an argument for patients to keep smoking, and playing Russian roulette with their bodies? Of course not. Maybe someday we’ll be able to tell which people will get cancer, but we definitely can’t now.
(Update: Orac agrees! I’m flattered!)
Hi Graham,
While you raise a good point about the ultimate destiny of any individual is unpredictable, I think it is too much to say that the “Brits are right” in this case. The study looks at whether people think they would get cancer or not regardless of their lifestyle habits (namely, smoking). That is to say, the respondents who answered “No” think that if they did get cancer, smoking wasn’t the culprit. This is not true. Most of the people who will eventually get cancer can attribute it to their smoking. Therefore, the people are misinformed about the dangers of smoking (higher in indigent populations).
I agree with what you’re saying, Southpaw, and understand your point of view, but I read the study differently–it wasn’t a study of people with cancer, asking them what they attributed it to–it was a study of the general population, asking hypothetically about why they would get cancer.
(Personally I’d like to see the exact way the questions were asked, but I can’t seem to find it on the web.)
In a technical and philosophical sense, Graham, I think you’re right. Carcinogenesis is an incredibly complex process and it seems unlikely that we’ll ever be able to predict with 100% certainty which individuals will develop cancer and when, based on the sum total of their genetic make-up, epigenetic profile, environmental exposures, and lifestyle choices. And this is analogous to many other situations in medicine where, as physicians, all we have available are outcome risks for subpopulations based on statistical models. The temptation – because patients ALWAYS ask – is to misapply these population risks to individuals. I can’t count the number of times patients have asked me “how long do I have?” or “is my aneurysm going to rupture?”.
But just to say “I don’t know, it’s up to fate” in these situations is being needlessly reductionist where being practical is important. Technically it’s right, but it’s not what the patient needs to or even *wants* to hear. In my experience, the average patient doesn’t think this way about their problems.
So when you ask average people on the street “If you develop cancer, what would have caused it?” and they answer “Fate”, do you think they answer with an understanding that scientific progress has not yet realized personalized medicine, or do you think they just mean “God” or “I have no idea”? I think it’s probably the latter, and probably why the British survey was interpreted to be so worrying to public health officials. Yeah, the British respondents are right when they say “Fate”, but they’re right for the wrong reasons.
Nice post by Ray. I agree that not having the questions that were asked makes it difficult to deduce an interpretation of the results.
If you’re interested, I wrote a brief post about the study and its findings, you can check it out here:
http://mudphudmusings.blogspot.com/2007/01/fated-to-get-cancer.html
Actually, if I’m reading Junkfood Science right, not only does overweight not cause diabetes, but it is protective against certain complications of diabetes.