Dichloroacetate (DCA)
Other common name(s): dichloracetate
Scientific/medical name(s): sodium dichloroacetate
Description
Dichloracetic acid and sodium dichloroacetate are man-made chemicals that have not been found in nature.
The pure form, dichloracetic acid, is a strong acid that can burn the skin and injure tissues. It can cause spasms of the body's airways if it is inhaled. Dichloracetic acid is used in the process of making certain other chemicals, including some drugs. It has also been used as a medicine to remove warts or other skin growths.
Sodium dichloroacetate is a different ("buffered") form of the same chemical. This form is not an acid, and can be taken by mouth without causing burning. The term "DCA" in this information refers to this form of the chemical.
DCA can also be absorbed into the body through the skin.
Overview
DCA has been tested in humans on a small scale for rare diseases of metabolism (energy production), but has recently shown some promise in the lab for cancer treatment. This has led some people with cancer to try taking DCA on their own. DCA is known to cause nerve and liver damage, as well as some other side effects. It may also be able to cause cancer in humans, but that has not been proven.
At this time, clinical trials (studies on human volunteers) have just been started to find out if DCA might be helpful against cancer. No human studies have been completed yet, so it is unclear how or whether it might help, or what the proper dose might be.
How is it promoted for use?
Mainly, DCA is promoted as a cancer treatment, though some have touted it for use in other chronic illnesses. In 2007, some news and Internet outlets reported on a study of DCA showing it slowed the growth of tumors in animals and of cancer cells in the lab. Certain sources seemed to suggest that DCA could kill cancer cells when nothing else worked -- a potential cheap and easy cancer cure. Some suggested that because DCA couldn't be patented and drug companies couldn't make much of a profit on it, no one would study it. A few of these people have made it seem that the cancer patient's best hope might be DCA self-treatment.
What does it involve?
DCA is not legally available as a drug or supplement in the U.S. other than through clinical trials, so it is not easy to obtain. A few people are able to get DCA through other countries. Some suppliers sell only industrial or technical grade dichloroacetate, which is not made with the same purity standards as pharmaceutical grade DCA.
Sodium dichloroacetate is sold as a powder. Doses are based on how much the patient weighs in kilograms (a kilogram is 2.2 pounds.)
It is not clear if DCA is effective against cancer, so the best dosage for people trying to treat cancer is unknown. People have reported taking from 8 milligrams per kilogram (mg/kg) of body weight per day to 50 mg/kg per day. Some patients split the full day's dose into 2 smaller doses and take it twice a day. Because the risk of side effects goes up with higher doses, most DCA supporters suggest taking 30 mg/kg or less per day and watching for side effects. Some people take days off from DCA (for example, skipping weekend doses) to try to reduce the chance of serious side effects.
The powder is mixed with water, juice, or tea and drunk. Some DCA promoters recommend taking caffeine and extra thiamine (vitamin B1), hoping that this will help the DCA work better and reduce the risk of nerve damage. Others suggest taking it with food or just after a meal because it can irritate the stomach. But it is not clear if any of these suggestions might make it work better or reduce side effects.
What is the history behind it?
Dichloroacetic acid was first made in 1864. It has been used mainly for industrial purposes (largely in creating other acids and chemicals). But aside from removing warts or other skin growths, it has not been found to have medical uses.
In the late 1970s, doctors noted that sodium dichloroacetate (DCA) could reduce the high blood sugar levels common in certain people with diabetes. Interest waned as other drugs worked better. But by the 1980s, doctors had found that DCA might help people who had lactic acidosis (a rare but serious condition in which the body's acid-base balance is dangerously out of whack.) Clinical trials were started as early as 1990 to look at DCA use in children with lactic acidosis due to inborn errors of metabolism (problems with using food to produce energy). DCA was also studied to see if it could help other conditions, mainly involving lactic acidosis.
In recent years, doctors at the University of Alberta (Canada) have been trying to normalize the way that damaged mitochondria in cancer cells worked. (Mitochondria are tiny structures inside cells that produce energy and do other tasks.) These doctors observed that in the lab, abnormal mitochondria seemed to help keep cancer cells alive. If they could change the way their mitochondria processed energy to a more normal function, they thought that either the cancer cells would die or become non-cancerous.
The researchers reasoned that DCA, which can affect an important enzyme in mitochondria, might help restore their normal way of functioning. In January 2007, the researchers published a study showing that DCA was able to slow the growth of cancer cells from the lung, breast, and brain in a lab dish. This study also found that laboratory rats that had DCA in their drinking water had much slower tumor growth than those not treated with DCA.
Some news and Internet outlets reported on the study. To some, the story held out hope for a cancer cure. The story received widespread attention, implying that an affordable, safe treatment was available but because DCA couldn't be patented, no one would study it.
Because it is not an approved drug, only doctors doing research on DCA can prescribe it. But the interest in DCA after the 2007 study led to some companies selling DCA directly to patients over the Internet. The FDA became involved, since sellers were marketing a drug that hadn't been proven, and that was not approved for sales or marketing in the U.S. On those grounds, the FDA has stopped at least one shipment of DCA from entering the United States.
What is the evidence?
DCA has been studied for some time as a drug to treat certain illnesses other than cancer. Medical researchers have tested it for decades in helping reduce the buildup of lactic acid in the body. Although not a threat to healthy people, lactic acid can overwhelm people with certain problems, and become so severe as to threaten life. For instance, children with genetic defects that affect mitochondria cannot process lactic acid. Tests have not shown it to work well so far for this problem in part due to side effects, but doctors are still working on it.
It has also been studied for lactic acidosis due to other causes, including severe head injuries, malaria, and monochloroacetic acid poisoning. It is still being studied for these kinds of uses.
It has also been tested on people with very high cholesterol levels.
In 2007, a Canadian study found that rats with cancer that were given DCA in their drinking water had much slower tumor growth than those not given DCA. They also found that DCA killed lung, breast and brain cancer cells, but not healthy cells, in tissue cultures (laboratory dishes).
Since that time, several studies have been done in the lab looking at the effects of DCA on cancer cells in a dish or in animals. Prostate cancer cells seemed to be easier to kill with radiation if they had been exposed to DCA. Breast cancer cells implanted into rats' tails spread into fewer areas if the rats were given DCA. Cancer cells from the endometrium (lining of the womb) were more likely to die with DCA exposure, although this only held true for the mildly to moderately invasive cancer cells. The very aggressive cancer cells were not affected by DCA.
Canadian researchers are now starting to look at using DCA in people with cancer. Studies to find safe doses of DCA in humans are now under way. One study is looking at DCA for cancer that has spread or come back. Another is looking at whether DCA can boost the effectiveness of radiation treatments. There are also U.S. studies looking at toxicities and how to reduce DCA side effects.
But as of late 2009, no studies in humans have yet shown that DCA can help treat cancer. Available evidence does not support the use of DCA for cancer treatment at this time.
Are there any possible problems or complications?
This substance may not have been thoroughly tested to find out how it interacts with medicines, foods, herbs, or supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.
Some studies of people who took DCA for reasons other than cancer have found that it may cause drowsiness, fatigue, upset stomach, and lowered blood sugar levels. Some people had changes in their blood chemistry over time that suggested that their livers may have been affected. Liver function seemed to improve after DCA was stopped.
DCA may cause nerve damage in some people when taken for a long time (months or years) and can result in weakness and numbness in the arms and legs. This can lead to trouble walking. These nerve effects tend to get better over a period of weeks after the DCA is stopped. This effect has happened even in people who were taking thiamine (vitamin B1) to help prevent nerve damage.
In mice and rats that were given high doses, the effect on the nerves did not get better after DCA was stopped. Liver damage was also seen at high doses. Dogs that got higher doses had eye problems, trouble walking, and trouble breathing; some had diarrhea and weight loss. DCA causes liver cancer in lab rodents when put in their drinking water. Keep in mind, though, that drugs do not always affect people and animals in the same way. It is hard to say without further testing which of these effects might also happen in people, and whether higher DCA doses might cause permanent damage.
People who are very sick do not process the drug as quickly as those who are healthier, so that people with health problems may build up toxic amounts of DCA over time.
Women who are pregnant or breastfeeding should not use DCA. People who are getting other cancer treatment with similar side effects (such as liver or nerve damage) might expect to have these effects worsened. Anyone who is taking DCA should be under a doctor's care to watch for liver damage and problems with blood chemistry that may result.
It is not clear if DCA might also affect a person's risk for getting a new cancer. The US Environmental Protection Agency (EPA) has listed dichloroacetic acid as "likely" to be a cancer-causing agent in humans, although this is based mainly on studies in animals. Dichloroacetic acid is also on the California Environmental Protection Agency (CalEPA) list as a cancer-causing agent and as a cause of reproductive harm in men. The International Agency for Research on Cancer (IARC) does not have enough studies on people to be sure, but based on the evidence that is now available, says that dichloroacetic acid can "possibly" cause cancer in humans.
Relying on this type of treatment alone and avoiding or delaying standard care for cancer may have serious health consequences.
