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  • I have a rather unpleasant secret to tell you. Something that the cancer research community

  • don't really like to talk about. Here it is: "There are no cures for cancer, and it's highly

  • unlikely there ever will be." I'm sorry, that's simply the harsh reality. We may develop better

  • and better treatments, we may develop vaccines or preventative measures, and our lifestyles

  • may improve over time. Our ability to diagnose will steadily improve, and someday the shrink

  • ray or biofilters or nanobots may make cancer a minor inconvenience, but cancer is built

  • into our biology. It's... us, gone abnormal. It is as diverse as we are, and possessed

  • of the same adaptability, resistance to harm, and made of the same stuff.

  • This is what makes it so difficult to treat. Poisoning cancer means poisoning a part of

  • us that's acting selfishly. The differences between our normal cells and our cancer cells

  • are small, and scientists attempt to exploit those small differences to design cancer therapies

  • that are more harmful to the patient's cancer than it is to the cancer patient.

  • So, a lot of people have sent me a request to address the recent announcement by the

  • University of Alberta on the cure for cancer called DCA. The very phrase "cure for cancer"

  • tells me that a researcher is not writing this press release. It's mostly filled with

  • misinformation, or at least marketing spin, and I want to explain the why and how of DCA

  • for cancer. It is a promising drug for cancer therapy, but the evidence doesn't match the

  • hype its receiving.

  • DCA stands for dichloroacetic acid, which is a very small, very simply compound. It's

  • a byproduct of municipal water purification, specifically of chlorination, and getting

  • rid of it safely is the subject of a lot of research. It's not a nice chemical to dump

  • in our waterways, so making sure all of it is recovered is important.

  • DCA has also long been used to treat certain metabolic disorders. It inhibits an enzyme

  • involved in the metabolism of sugar in the mitochondrion. This is important for people

  • who overproduce lactic acid, which DCA helps to reduce the production of. It's been approved

  • for use for lactic acidosis for years, where it's pretty effective.

  • So, we know that DCA is a byproduct of water treatment, and we know that there medical

  • uses of it for metabolic disorders. Now we get to the exciting part. It turns out it

  • has metabolic effects on cancer as well. Cancer cells have long been known to have unusual

  • mitochondrial biology, going back to a German doctor named Warburg, and the effect is called

  • the Warburg effect.

  • Tumor cells often use glycolysis instead of oxygen based respiration. Glycolysis is an

  • alternate way of burning sugar that is less efficient, but not dependent on the delivery

  • of oxygen. This means that a tumor can grow beyond the ability of the blood vessels around

  • it to support its normal oxygen demands. That's why tumors are often dense masses, hard to

  • penetrate with normal chemotherapies.

  • A second effect of glycolysis is that it interferes with the normal cellular suicide that damaged

  • cells commit, called apoptosis or apoPtosis. If we could coax cancer cells into only using

  • respiration, they wouldn't be able to grow so big without more blood vessels to supply

  • oxygen. If we could coax their mitochondrion into normal functioning, it could trigger

  • cellular suicide responses, as they recognize themselves to be malfunctioning.

  • So, does DCA do this? Yes, it does, in certain types of tumor, especially in neuroblastoma,

  • although the results are still pretty preliminary. What makes DCA most valuable, in my estimation,

  • is that it cooperates or synergizes with other types of therapy. It helps the action of traditional

  • chemo, by making the cancer cells more sensitive to oxygen metabolism, or more frail to metabolic

  • interference. So far, it's proven that it increases the effect of radiation, gene therapy

  • and

  • DCA is pretty exciting as an adjunct therapy, and that's currently being examined. By itself,

  • it's effective on a few types of cancers that are very glycolytic but in combination it

  • may improve outcomes for a broader variety of cancers.

  • It's important not to uncork the celebratory bottle of champagne just yet, though. So far

  • the effects are pretty modest and there are some toxic effects that limit the dosage that

  • can be used.

  • When it was tested in cancer cells grown in a flask, it reduces progression in some cases.

  • In the case of some cell lines, it increased the cellular suicide level by 10 fold.

  • However, in others, it actually made the cancer cells "worse" by protecting them from oxygen

  • starvation. It was also shown to interfere in some cases with the front-line drugs cisplatin

  • and doxorubicin. We're going to have to work out these paradoxes before it can go into

  • use.

  • In animal testing, the results were a little more positive. Colon cancer tumors showed

  • 20 to 40 percent reductions in progression vs. untreated animals. That's not as good

  • as some present drugs, but still pretty effective.

  • So, modestly effective in cells, reasonably effective in animals, what about human testing?

  • Human clinical testing has never been conducted in the US. Canada ran a safe dose study, where

  • they give patients escalating doses to determine what amount is safe, and what amount is effective.

  • We know from prior studies that DCA can, ironically, cause cancer, and that it can cause neuropathy,

  • or nerve damage which can be severe at therapeutic doses that someone might get for lactic acidosis.

  • The Canadian dose escalation started in 2007. 50 patients were enrolled, but only 5 were

  • actually treated, and as I understand it they spent 800,000 dollars for that very small

  • result. The official conclusion of the study is linked in the underbar, but the short version

  • is that the investigators said that no conclusions could be drawn about the efficacy and safety

  • of DCA for cancer therapy. So we still have no idea if it will be very effective. Five

  • treated patients, in the history of a drug, is not enough data to go on.

  • DCA is one of many possible avenues that cancer researchers are pursuing, a useful adjunct

  • to conventional therapy, although it's still in the early stages of testing and research.

  • Why is it being promoted? Why am I getting so many messages about it, when no-one has

  • asked me about cancer immunotherapy that is a LOT more exciting and promising?

  • It's because DCA is an unpatentable substance. It's too historical for anyone to claim to

  • have invented it. That means that the drug companies have little or no interest in it.

  • Who can blame them? Oh, I know, Big Evil Pharma love making money, but well... so does every

  • company, and most employees, too, come to that. We run businesses at a profit, and if

  • DCA can't be sold for profit, then how will those companies recoup the cost of the 2 to

  • 500 million dollars it may take to bring the drug to market? The management of the drug

  • companies are tasked with making money. DCA won't likely compete with existing drugs,

  • may enhance effectiveness of those products, but it's not a profitable venture for them

  • to invest hundreds of millions of dollars into.

  • We can deplore the profit motive, but the purpose of business is to make money. Either

  • the government or a non-profit will have to step in to complete the safety review, testing

  • and manufacture. The University of Alberta are funding their DCA research program on

  • a combination of public donations and government funding. I think the reason why this topic

  • keeps hitting the news and email forwards is that they have hired marketing people to

  • get the word out, to promote the product, and to try to get some funds. So, they take

  • the story of a compound with a small but useful effect in certain tumors, and they blow it

  • up to epic proportions, the cure for cancer.

  • I'm thinking it's time for a third C0nc0rdance's Law, so here it is:

  • "Any scientific discovery announced in a press release is almost always less impressive than

  • it sounds." c0nc0rdance's Third Law.

  • I hope I haven't discouraged any of you out there from a future in cancer research. We

  • may never find a cure, but it's one of those jobs where you wake up in the morning with

  • the potential to save thousands of lives. Nothing beats that feeling.

  • Thanks for watching.

I have a rather unpleasant secret to tell you. Something that the cancer research community

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DCAとがん (DCA and Cancer)

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    VoiceTube に公開 2021 年 01 月 14 日
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