Map of life expectancy at birth from Global Education Project.

Friday, July 08, 2011

It's not the first time Gina Kolata has missed the point

She seems to think this incident with some Duke exposes some deep problem with efforts to develop targeted cancer therapy. Actually, this seems to be nothing but a good old fashioned case of scientific fraud combined with for-profit quackery. That's not to say, however, that we should be expecting any miracles.

Here's the simple background. "Cancer" is not one disease, it's an inclusive term for defects in the regulation of cellular reproduction in which abnormal cells can proliferate to sites in the body beyond their point of origin. (I just made that up but I hope most specialists will say it's good enough for a blog post.) Cell growth and replication are governed by genes, so ultimately these are the result of genetic abnormalities. In addition to losing the usual regulatory processes that keep cells specialized to the correct form, dividing only when they should, and staying where they belong, tumors need to recruit blood supply, and evade immune system mechanisms that can kill abnormal cells, and avoid fail-safe mechanisms that cause abnormal cells to kill themselves, among other problems.

There are innumerable different genetic changes that can accomplish (if that's the right word) these results, and various phenotypic strategies that can result. Therefore, a drug that effectively suppresses cancer cells in one case may not work in another, because it's targeting some specific feature that some cancer cells have and others don't. And so researchers are looking for ways to identify the specific characteristics of specific cancer cells that make them open to attack by equally specific agents.

It sounds good but don't get too excited. This can actually be viewed as bad news. There isn't going to be a big announcement one day that somebody has found the cure for cancer, followed by a super-duper-mega-hyper Nobel Prize. Cancer is actually a gazillion different diseases -- even cancers that start in the same kind of tissue, such as breast cancer or liver cancer, are each dozens of different diseases or maybe even an indefinite number. So the best you can hope for is incremental progress, finding ways of knocking them down one at a time.

And it gets worse. Cancer cells not only reproduce abnormally, their messed up regulatory mechanisms mean they mutate at a high rate. Which means that cancer cells can evolve resistance to drugs that are initially effective. Meaning that most strategies won't produce a cure, but will only hold the cancer in check for a while.

So, fraud or no fraud, unless somebody comes up with a whole new category of idea, we're going to keep spending billions on research and treatment and we're going to keep getting slightly better results for limited numbers of patients with each hard won advance. And the patients who can benefit are also going to be limited to the ones who are lucky enough to be affluent enough to purchase health insurance, or live in rich countries that provide it for them. Which means that everybody is paying for it. But -- each advance means that cancer treatment gets more expensive, because there are more patented, highly expensive treatments to be applied, each of which buys only a limited amount of time before you go on to the next one, if you're lucky.

Obviously, this can't go on indefinitely. But where does it stop, and how? Nobody even wants to think about it, apparently.


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