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Posts Tagged environment

Is cancer due mostly to “bad luck”?

One of the more difficult conversations to have with a patient as a cancer doctor occurs when a patient, recently informed of her diagnosis of, for example, breast cancer, asks me, “Why did I get this? What caused it?” What almost inevitably follows is an uncomfortable conversation in which explanations of the multiple known causes of breast cancer do not satisfy the patient. The reason, of course, is because when a patient asks, “What caused it?” she doesn’t mean what causes breast cancer in general or in statistical terms. Rather, she means, what caused my breast cancer? It’s a question that can only occasionally be answered. For instance, if it’s lung cancer and the patient is a smoker, then it was almost certainly smoking that caused the cancer, because lung cancer is a relatively rare cancer in the absence of smoking. In the case of breast cancer, contrary to the prevailing belief that leads women with breast cancer to be puzzled about how they could get it when there’s “no cancer” in their families, only around 5-10% of cases have a familial or genetic component. That means that around 90% of breast cancers are what we call “sporadic,” which means that we can’t identify a specific cause. Or, as I like to say, “We just don’t know.” Worse, in the case of breast cancer, the environmental factors we know about appear to contribute modestly at best to the risk of cancer. (More on this later.)

Understandably, patients hate hearing “We just don’t know,” some vague handwaving about genes, and that there is nothing that we know of that they did that caused their cancer. People—including oncologists—really don’t like the concept of “sporadic” cancer, mainly because humans crave explanation. The default assumption is that everything must happen for a reason and there must be a cause for every disease or cancer. Perhaps the most ridiculously emphatic statement of this that I’ve encountered thus far comes from (who else?) über-quack Mike Adams when he heaped contempt on the idea of sporadic disease as “spontaneous disease.” He did this in the context of a story describing how, after Dr. Mehmet Oz had followed recommended care and undergone screening colonoscopy to look for polyps, he was shocked that he actually had some. This led Adams, in his usual inimitable fashion, to construct a straw man so massive that it could be seen from space when he set it on fire, declaring that “colon polyps, in other words, appear without any cause!” and that “mainstream medicine…believes in the theory of ‘spontaneous disease’ that ‘strikes’ people at random.”

Not exactly.

On the other hand, there is a lot of randomness in disease, not just cancer, as hard as it is for Mike Adams, or anyone to accept. Just because there is a varying amount of randomness in who gets a disease does not mean that mainstream medicine claims there is no cause to these diseases. Rather, for diseases like cancer, it’s a stochastic process, meaning that chance can play a role—sometimes a big role—in determining who gets sick. Indeed, just last week there was more evidence supporting this idea published in Science. Unfortunately, much of the mainstream press coverage presented the message of the paper a bit too simplistically. Even more unfortunately, it was the authors who encouraged this, as did the Johns Hopkins University press release about the study, which was entitled “Bad Luck of Random Mutations Plays Predominant Role in Cancer, Study Shows“. Yes, I groaned when I read this title.
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Posted in: Basic Science, Cancer, Epidemiology, Science and the Media

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The 2008-2009 Report of the President’s Cancer Panel: Mostly good, some bad, and a little ugly

Mark Crislip is always a hard act to follow, particularly when he’s firing on all cylinders, as he was last Friday. Although I can sometimes match him (and, on rare occasions, even surpass him) for amusing snark, this time around I’m going to remain mostly serious because that’s what the subject matter requires. I’ve said it before and I’ll say it again: I’m a bit of an odd bird in the world of cancer in that I’m both a surgeon and I run a lab. Sadly, there just aren’t very many surgeons doing basic and translational research these days, thanks to declining NIH funding, increasing clinical burden necessitated by declining reimbursements, and the increasing complexity of laboratory-based research. That’s not to say that there aren’t some surgeons out there doing excellent laboratory research, but sometimes I feel as though I’m part of an endangered species, particularly years like this when grants are running out and I need to renew my funding or secure new funding, the consequence of failure being the dissolution of my laboratory. It’s a tough world out there in biomedical research.

As tough as biomedical research is in cancer, to my mind far tougher is research trying to tease out the relationship between environmental exposures and cancer risk. If you want complicated, that’s complicated. For one thing, obtaining epidemiological data is incredibly labor- and cost-intensive, and rarely are the data clear cut. There’s always ambiguity, not to mention numerous confounding factors that conspire to exaggerate on the one hand or hide on the other hand correlations between environmental exposures and cancer. As a result, studies are often conflicting, and making sense of the morass of often contradictory studies can tax even the most skillful scientists and epidemiologists. Communicating the science and epidemiology linking environment and cancer to the public is even harder. What the lay person often sees is that one day a study is in the news telling him that X causes cancer and then a month later another study says that X doesn’t cause cancer. Is it any wonder that people are often confused over what is and is not dangerous? Add to this a distinct inability on the part of most people, even highly educated people, to weigh small risks against one another (an inability that has led to phenomena such as the anti-vaccine movement), and the task of trying to decide what is dangerous, what is not, how policy is formulated based on this science, and how to communicate the science and the policy derived from it to the public is truly Herculean.
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Posted in: Cancer, Politics and Regulation, Public Health

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Robert F. Kennedy, Jr., vaccines, the EPA, and the interface with science-based medicine and public policy

This blog is entitled Science-Based Medicine for a reason, and that’s because we here at SBM believe that the best method to result in the most efficacious treatments for the most people is through the application of science to the evaluation of the biology, pathophysiology, and treatment of disease and disorders.

I may (or may not) be departing a bit from the views of my co-bloggers with this belief, but for purposes of this blog I consider “medicine” to go far beyond what we as physicians do when we undertake to treat patients. In fact, in my view, the purview of science-based medicine should not be so limited but should include any area where decisions, actions, or policy have a direct impact on health. Thus, my definition of science-based medicine encompasses environmental policy, because of the profound effect on human health environmental pollution and toxins can have. Unfortunately for those of us who don’t like its messiness, such a view drives me even more directly into politics than previous issues I’ve taken on. Like Dr. Novella, I rarely write about politics, but when it directly impacts science-based medicine. Mostly, such discussions here on SBM have involved the regulation of the medical profession by government, as Dr. Atwood discussed recently (1, 2, 3) in the context of the difficulties medical boards have in preventing quackery to my discussion of how a quack like Dr. Rashid Buttar could continue to practice in North Carolina, despite his despicable preying upon desperate cancer patients and the parents of children with autism, not to mention the frequent criticisms of the National Center for Complementary and Alternative Medicine. Dr. Sampson, on the other hand, was more than willing to examine a much more explicitly political issue, namely the number of Iraq War dead (1, 2), and that provoked a bit of disagreement with our commenters, not to mention me.

Recently, hot on the heels of the election of Barack Obama in the Presidential election last week, an issue relevant to several aspects of where science-based medicine intersects public policy popped up. Steve Novella has already commented on it on his own blog, as have numerous other medical bloggers, science bloggers, and political bloggers but I feel justified in commenting on it here, for the reasons that I’ve just mentioned. The controversy is that antivaccine activist and true believer in the scientifically discredited notion that mercury in the thimerosal preservative in vaccines causes autism, Robert F. Kennedy, Jr., is being seriously considered by Barack Obama either to head the Environmental Protection Agency or even to be Secretary of the Interior. Like our fearless leader Steve, I believe that such a selection would be an unmitigated disaster for science policy in government.
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Posted in: Politics and Regulation, Public Health, Science and the Media, Vaccines

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