ASCO Part 2: CBD and Cancer

I'm still looking at (and reporting on) some of the sessions at the 2020 ASCO Virtual Education Program, help earlier this month. These sessions don't present the new scientific research about cancer. Instead, they offer continuing education for oncologists on ways to be better, more informed doctors.

The latest session I have looked at is called Complimentary Alternative Medicine. 

As a quick reminder, let me explain the difference between Alternative Medicine and Complimentary Medicine, because they are different in important ways. In cancer, Alternative Medicine suggests treatments that are different from standard cancer treatments like chemotherapy, radiation, and immunotherapy. They offer alternatives to these treatments. From what I read in online groups, they are fairly popular with a lot of cancer patients. That's usually because people want to avid what they see as the negative side effects of things like chemo, though sometimes it's (sadly) because they can't afford things like chemo. The problem with Alternatives is that they are not proven to work. That might be harmless in some situations, but a study from a few years ago found that patients who rely on Alternative Medicine have a lower survival rate that those who take standard treatments.

That's complicated for Follicular Lymphoma patients. Some people may try Alternative treatments, and think they are working. But because FL can be a slow-growing disease, it's not the Alternative treatment that's doing the job; it's just the slow-growing nature of the disease. So if the FL becomes more aggressive, and the patient relies on the Alternative treatment that they think has been working, that could lead to unnecessary trouble, if they avoid standard treatment.

So that's Alternative Medicine. Complimentary Medicine (also known as Integrative Medicine) is different. Instead of replacing standard treatments, it compliments them, working with them to make them better (or to give the patient a better experience with them). Complimentary Medicine might have patients take standard chemotherapy, but then suggest something like yoga or tai chi to help with side effects. Or maybe marijuana to help with nausea. The chemo is still there. But the Complimentary treatment helps make the experience a little less awful.

So this session looks at Complimentary Medicine, and one of the presentations was "Cannibidiol Use in Oncology" by Dr. Tina Rizack.

Cannibidiol is also known as CBD, and, as Dr. Rizack points out, it has become fairly popular in recent years. A lot of the presentation gave some background about what CBD is and how it works, which was interesting (and might be especially interesting to the doctors that the presentation was meant for). I'm going to skip some of that background and get to the highlights.

CBD is a component of marijuana. Unlike THC, another component, CBD does not contain the compounds that make someone high. But it may have some other very positive effects.

I'm going to emphasize that word again: CBD may have some positive effects. I know from speaking with people who use it (I have never tried it myself) that it is very effective for some, but not for others. There are lots of reasons for the differences: the CBD content of a product does not always match up with what it says on the label (studies have shown there can be anywhere from 30% to 69% difference, so you might only be getting 1/3 of what you think you're getting). Quality can be a major issue, with some CBD products having impurities that interfere with effectiveness. And some people may just not get an effect, as with any medicine (Tylenol doesn't do a thing for me when I have a headache, but it works great for one of my kids). 

So what is it good for? Well, a lot of what we know comes from reports from individuals, rather than from larger studies, though there are some large studies out there. 

Right now, the only thing we know for sure, based on rigorous research, is that CBD helps children with certain rare types of epilepsy. That's the only large study that has led to an FDA approval. There have been some smaller studies that suggest a possible benefit, but none that have been tested on a large scale, such as a phase 3 trial.

Some of the uses that are related to cancer include pain reduction. Some standard cancer treatments, as well as some types of cancer, can cause pain that might be reduced with CBD. There is a study going on now in Australia that looks at palliative care in cancer patients, and early results seem to show that CBD may reduce pain. 

(I'm sorry that I don't have links to these specific studies. I really don't like mentioning research without giving you a way to look for yourself, which is really important. But since these are video presentations, they don't always give a lot of detail about where the information came from. But given that it's an ASCO presentation, by doctors for doctors, I trust the source.)

There is also some research that CBD can reduce the nausea that some treatments (like some chemotherapies) can cause. One found that CBD (and THC) improved the standard anti-nausea drugs that were given to cancer patients. But that was 10 years ago, and there hasn't been a study since that compared CBD to some newer, more effective anti-nausea treatments that are usually given today.

Other studies have shown that CBD helped patients with Graft-versus-Host disease, which happens when a patient's body rejects a transplant (including Stem Cell transplants that are common with some blood cancers). 

There is also some suggestion that CBD might help some people sleep better, maybe because it reduces pain and anxiety. And there is at least one study that shows, at certain doses, that CBD can reduce anxiety.

(Interestingly, the presentation said that people of different ages take CBD for different reasons. Younger people tend to take it to reduce anxiety, while older folks take it to reduce pain. That fits pretty well with the people that I know who take it.)

There is still a lot that needs to be tested with CBD. Dr. Rizack counted 247 clinical trials related to CBD, with 47 still recruiting. 9 of them were related to pain, and 2 to cancer (one for nausea and one for Graft-versus-host), with 1 more related to anxiety.

One final point -- there is NO EVIDENCE that CBD cures cancer, or that THC or any other compound from marijuana cures cancer (though an ASCO survey last year found that 39% of Americans think that marijuana does cure cancer). Maybe we'll have evidence for that some day, but for now, legal restrictions on research have made it hard.

So here;s the bottom line:

CBD may help some people with pain, anxiety, and nausea. Or it might not. The good news is that it's not addictive, and almost impossible to overdose on. The bad news is, it's easy to find CBD that is not effective, or contaminated, or at a lower dose than the product label says. CBD can also interfere with some medications, including some antibiotics and certain types of chemotherapy.

My advice, if you're looking for my advice, is to ask your oncologist before you try it. There's a chance he or she won't know much about it, so if there is an Integrative Medicine department at your cancer center (or at a nearby research hospital), ask them for advice. They may know of a reputable source, and have some suggestions for dosing.

Like any Complimentary Medicine, CBD might be a help, and the evidence from the ASCO presentation seems to suggest that taking it won't do much harm. But better to check with a doctor, the way you would before taking any kid of treatment, whether it's Standard or Complimentary.