Cure for cancer? Not.
This DCA story keeps dogging me. A cheap drug which kills all cancers! But Big Pharma won’t let the cat out of the bag, because it’ll kill their billion-dollar profits! Does a story get any sexier than that? Think about it: cancer fears; a discovery that would spark hope in millions of patients and their loved ones; and a great whopping conspiracy theory to top it all off. Wow.
My credentials, such as they are, for those folks who wander in from a Google search for DCA or dichloroacetate: I have an MD/PhD, and the PhD is in cancer biology. Full disclosure, though: I’ve never been involved in cancer research and my PhD was awarded in 1990. A lot changes in 17 years, believe me, and at best I’m only an armchair cancer biologist.
Follow me below the fold.
You know the line, “If it sounds too good to be true, it probably is”? With respect to DCA, that’s almost certainly the case. We’re talking about a drug which has not seen a single cancer-related clinical trial. Is the preliminary data exciting? Sure it is. But there are a number of factors which should temper anyone’s enthusiasm:
1. There is no single disease, “cancer”. Every type of cancer is genetically and behaviorally unique. Within a single type of cancer, every patient’s cancer is genetically and behaviorally unique. And within a single patient, that cancer’s genetics and behavior changes over time. That’s why very few types of cancers are cured with chemo alone, by the way. And it’s also why the only chance a patient has with some cancers (like pancreatic) is surgical. If you can physically remove the cancer, you have a shot at cure. But with pancreatic CA, one of the most lethal of all cancers, I think the 5-year survival is still only 22% even if you’re in the lucky minority who can have surgery.
2. In medical research, there’s a long history of diseases cured in tissue culture, cured in animal models, etc. Tissue culture and animal models are important, but they are no substitute for human studies. I’m particularly sensitive about this point. If my wife were a mouse, her MS would have been cured back in the 80s. LOTS of drugs have worked dramatically for animal cancer models — I’m thinking back to the 90s, when we thought the anti-angiogenesis drugs were going to be the next cure-all, based on mouse (or rat?) studies. Ten years later, these drugs are seeing limited use, but they’re far from being panaceas.
3. In any given tumor, you have a population of cells with genetic variability within the population. Think of it as evolution on a small scale. When you radiate or give chemo to the patient, you’re applying selective pressure to that population. Many die, but the ones who resist are left behind to continue their cell division. Only now you have a new population, don’t you? Newer, tougher. Point is, DCA (this new wonder drug) might have some efficacy against cancer, but until we hold human clinical trials, we have no way of knowing how readily human tumors can ‘outwit’ (if you’ll forgive the anthropomorphism) the drug.
4. I think this particular story has legs because of the “Big Pharma is Baaad” meme. Since it’s a simple molecule (dichloroacetate — doesn’t get much simpler) and it’s out there in common usage (to treat lactic acidosis, apparently, although I couldn’t find it in the Physician’s Desk Reference), the pharmaceutical companies can’t make a profit off of it. And since it’s this big panacea, it would cost them billions in lost profits, yatta yatta.
My point over at Daily Kos*, when this story made the rounds the other day: if this drug is as great as everyone says it is, Big Pharma will FIND a way to make it profitable. Here’s one idea: link DCA to a large molecule which is cleaved from DCA in the liver, let’s say. The large molecule is something inert, has little biologic activity, or perhaps has anti-cancer activity of its own. Et voila. You have a large, patentable product, and you can doubtless devise a study to make it look better than DCA alone. Or say fuck it all, I’m not even going to compare it to DCA alone. I’ll do this trial: standard chemo regimen with “DCA-plus” versus standard chemo regiment alone. Wow! Look how great “DCA-plus” is!
But this all plays into people’s yen for conspiracy theories. Big Pharma hates us. And yes, I’ve indulged in this on my blog, I know, I know. Big Pharma is bad. But they also make money off of healing people.
You know what the worst part of this DCA flap is? It builds false hope. And when it comes to cancer, I think there are fewer things crueller than building false hope. It’s sadism, as far as I’m concerned.
*If you check out the comments to that DKos diary, I’m hobbitfoot. Just so’s you know.