10 Jul Re-inventing the Wheel – Cannabis and Cancer

Dr Peter McCormick of the University of East Anglia (UEA) in Norwich is in the news again for his ongoing research on cannabis extracts and cancer. The latest work is aimed at making a case for developing a synthetic alternative to cannabis which would have the same cancer treating properties but without any of the “unwanted side effects” of THC.

UEA Press Release

Dr Peter McCormick, from UEA's School of Pharmacy,

Dr Peter McCormick, from UEA’s School of Pharmacy

We have 5,000 years of recorded medicinal use with cannabis, The written history of medicinal cannabis goes back to around 2,700 BC, in the pharmacopoeia of Shen Nung, one of the fathers of Chinese medicine, so we should be pretty familiar by now with the issues cannabis use presents. So why take the risk with an unknown synthetic product? The answer sadly is perhaps more connected with either the government’s reluctance to see cannabis portrayed as a beneficial substance or pharmaceutical company profits (or both) than any real medical advantage.

Whatever the reason it isn’t hard to imagine the pressure bought to bear on studies looking at THC as a cure for cancer. If cannabis were shown to provide a cancer cure it would have a devastating impact on both the reputation of the prohibition policy and on the pharmaceutical industry’s profits.

That isn’t to accuse the research team, the universities involved and especially not Dr McCormick of some kind of sinister or corrupt agenda, of course not. It more likely indicates a general issue with the way research is funded in British universities and the resulting environment research has to operate within.


UEA Norwich

Perhaps this goes some way to explaining the stated aim of Dr McCormick’s research over a period of time. Around a year ago a press release from UEA announced exciting developments in the study of the effect of THC on tumours

Scientists at the University of East Anglia have shown how the main psychoactive ingredient in cannabis could reduce tumour growth in cancer patients.

Now this was interesting because it wasn’t looking at whether THC could shrink tumours, but how it did it. For all the sometimes extreme claims of the cannabis law reform activists it really does seem to be true that cannabis could form the basis of a cure for at least some types of cancer. Yes, an actual cure, not just something to make cancer sufferers feel better – although cannabis can do that as well – but actually to kill the cancer; a cure.

Now to be clear we do understand no-one is claiming that smoking cannabis spliffs is going to cure cancer, the researchers are looking specifically at the role of THC concentrates, also this wasn’t a study carried out on humans but on mice in a lab. But all this is perhaps an indication the claims of Rick Simpson with his high THC cannabis oil really do have some basis in hard science.

But the implication would seem to be clear, we have good strong evidence that THC could form the basis of a cure for cancer, this is fantastic news and one would have expected scientists working in this area to be really fired up to develop this discovery into a usable procedure, but no. The surprising aim of this wonderful research isn’t to see how cannabis derived drugs could be developed. As Dr McCormick stated:

“Our research uses an isolated chemical compound and using the correct concentration is vital. Cancer patients should not use cannabis to self-medicate, but I hope that our research will lead to a safe synthetic equivalent being available in the future”.

The use of the phrase “should not” is interesting and frankly doesn’t make any sense in the real world. If someone is dying with an incurable cancer why on earth should they not use cannabis to self-medicate, it might not work but what have they got to lose?

Of course ideally we are talking about using THC in a proper medical setting, in properly medically supervised conditions, the sort of conditions where far more dangerous procedures with serious side effects are routinely carried out.

The bigger issue is why does he suggest that we need to manufacture a “safe synthetic equivalent” when we know THC is remarkably safe, and what harms it does pose are well understood?

Finding the justification for this seems to be the reason underpinning the latest study carried out by his team.

There has been a great deal of medical interest in understanding the molecular mechanisms at work in THC, so that the beneficial effects can be harnessed without the side-effects.

There are side effects of THC and if you’re trying to shrink a cancer tumour these well known effects can be fairly described as unwanted. It is interesting to note though the word “serious” was not used along with “unwanted side effects” and this is the crunch. Current treatments for cancer have side effects that totally eclipse the worst cannabis has to offer, for example chemo can cause

Fatigue, Nausea and vomiting, Hair loss, Increased risk of infection, Anaemia, Bruising and bleeding, Mucositis, Loss of appetite, Damge to skin and nails, short-term memory loss and problems with concentration, Sleep problems, Reduced fertility, Diarrhoea and constipation and Depression

A side effect of Chemo 1: Mucositis
hair loss A side effect of Chemo 2: Hair Loss

Yet these side effects, serious and unwanted as they are, are considered to be worth the risk. The side effects of cannabis are mild in comparison, almost trivial. Yet Dr McCormick again makes the statement

Patients should not use cannabis to self-medicate, but I hope that our research will lead to a safe synthetic equivalent being available in the future.

The implication being that cannabis isn’t a safe treatment for a terminally ill person to try. So just what are the unwanted side effects of cannabis that would make this theoretical synthetic product something worth trying to design?

Dr McCormick’s team have been looking at the impact on memory of THC by undertaking further lab experiments on mice. Now cannabis is well known to produce short term memory loss although there is scant if any evidence that this is in any way permanent. The research team claim to have discovered the process by which this happens

They found that the absence of a particular serotonin receptor (5HT2AR) reduced some of the effects of THC – such as its amnesic effect, based on a standard memory test. But treatment to reduce 5HT2AR did not change other effects of THC, including pain relief.

The proposal seems to be to design a synthetic version of THC which by some mechanism also blocks the functioning of the 5HT2AR serotonin receptors. As is often sarcastically remarked with plans like this: “What could possibly go wrong?” The answer of course is “quite a lot”.

We would have precisely no experience of the new version of THC Dr McCormick’s team are proposing. The problem is that even small changes to complex long chain hydrocarbons like THC can lead to hugely different results in the human brain. By way of example, two of the cannabinoids made by the cannabis plant, THC and CBD, are structurally very similar; almost but not quite identical, but are almost chalk and cheese in the way they impact the human system. Who knows what unpredictable “unwanted side effects” a new synthetic version designed to reduce 5HT2AR might have?

At the very least any such new drug would take years to develop and then would need to pass the elaborate safety tests. It is unlikely to be cheap.

THC-a THC molecules

There is a one final twist to this story however. The cannabis plant doesn’t actually make THC, the substance recreational users enjoy so much. The plant produces the acid version known as THC-A. THC-A has all the medicinal benefits of THC but is not psychoactive, so should be free of the “unwanted side effects” the research team is so keen to avoid. If you didn’t know, in order to get stoned from cannabis, the resin produced by the plant has to be heated which converts the THC-A to THC, a process called “decarboxylation“. Simply eating resin straight from the plant doesn’t work recreationally.

It’s also worth mentioning in passing that all this involves experiments with mice – “in vivo” to use the terminology for animal experiments. A strong case can be made for the use of mice in order to find a cure for cancer, but is this latest study really so easy to justify?

In conclusion not only is the proposal to avoid the “unwanted side effects” of cannabis by creating a synthetic version of THC taking a huge risk in terms of safety for very little benefit, it’s really rather pointless because a non-psychoactive version already exists and in any case the research isn’t going to yield anything useful for many years, if ever. Meanwhile a cancer cure with great potential remains undeveloped and unavailable.

Studies like this are at best a distraction from the real issues surrounding cannabis, at worst an attempt to underpin prohibition by deflecting attention from the possibilities the plant can offer. It is worth pondering how much more progress could be made if this effort at the research level could be directed at actually applying the healing properties of cannabis. Why re-invent the wheel before you’ve even put it on the axle to see if it works?

The very real issue with the medicinal use of cannabis is the need for the many ill people who would get great relief from it to simply have access. The government still insists that cannabis has no medicinal value – none at all. Clearly that is wrong, deliberately so.

Derek Williams