Cancer’s a gamble but you can load the dice

This is an update on last week’s post on a paper on cancer by Tomasetti and Vogelstein. Fur has flown over this paper, in particular with some of the media coverage. There was an interesting, and angry, article in The Guardian, and remarkably an arm of the World Health Organisation (WHO) produced a press release on the paper. They were not impressed. And journalists reflected on their coverage of the article. It was all go.

This made me a bit worried, that my post may have been misleading, but fortunately, apart from the title, I don’t think it was. But with hindsight, the title is not great. Sorry.

The post basically concerned the paper’s conclusion on the observation that some forms of cancer, e.g., bowel, are much commoner that others, e.g., some kinds of bone cancer. These conclusions were not the controversial bit. But at the end of their paper Tomasetti and Vogelstein suggested that some cancers may be difficult to prevent, as they are due to, loosely speaking, chance.

This clearly bugged the WHO’s cancer agency. This is a subtle issue but I think I see the agency’s point. Roughly speaking, our current understanding is, I believe, as follows. The data on Americans that Tomasetti and Vogelstein use shows a 5% lifetime risk of getting bowel cancer, i.e., of 100 Americans, 5 will get bowel cancer. Unlike lung cancer and smoking, I think the status is that we don’t know a specific cause for most of these cancers. For lung cancer we know if we stop smoking we prevent many lung cancers. We probably don’t know of a specific measure that could do the same for bowel cancer.

So, we cannot predict which 5 of a 100 people will develop bowel cancer. But we do know something, as the WHO agency points out. It seems well established that bowel cancer is significantly more prevalent in some countries than others, e.g., is less common in Asia that in Europe and the USA. Now there are a lot of differences between here and Asia, so I guess it is hard to work out why the difference. However, this does suggest that if we were in some way less European and more Asian, then fewer than 5% would get bowel cancer.

So some headlines, and the title of my post, are a bit misleading. Cancer is a matter of chance but for many cancers, not just lung cancer, we may be able to do a lot to change the odds.