Cannabis Oil and Radiation Therapy for the Management of Pain
In this innovative approach seeking effective therapeutic strategies, the investigators are proposing to test the effectiveness of medical cannabis oil as an adjunct to palliative Radiation Therapy (RT) and Best Supportive Care to alleviate cancer pain that was only partially relieved with conventional medications. Furthermore, the investigators will assess the effect of medical cannabis oil on health-related quality of life and symptoms that are frequently associated with metastatic cancers including fatigue, anxiety, depression, insomnia and decreased appetite. The safety profile of medical cannabis oil with respect to prolonged use of more than two weeks of administration, concomitant medication use and palliative RT will also be examined.
|Condition or disease||Intervention/treatment||Phase|
|Metastatic Prostate Cancer Lung Cancer Breast Cancer||Radiation: Active PPP005 Radiation: Radiotherapy||Phase 2|
This is a 6-week randomized, double-blind, placebo-controlled, parallel group design trial followed by an open-label extension phase of 12 weeks, to evaluate tolerability of medical cannabis oil to reduce chronic pain intensity.
Consecutive adult patients between the ages of 18 and 75, male and female, with cancer pain, with an average weekly pain intensity score greater than 4 on the 11 points Numerical Rate Scale (NRS), will be prospectively recruited and invited to participate in this trial.
Informed consent will be obtained by a Research Assistant.
After baseline documentation with standardized scales, patients will be randomized to one of two parallel groups:
- Cannabis group: Delta-9 Tetrahydrocannabidiol (THC) /Cannabidiol (CBD) ratio 1:1 capsule
- Placebo group: Placebo capsule
- All patients will receive palliative RT to the symptomatic site. Patients will have a dose titration phase during the first week. The dose escalation will allow patients to adapt to the potential adverse effects (AEs) of the medical cannabis.
Follow-up visits either in person or by phone will be at 1 week, 3 weeks and 6 weeks of treatment.
At the end of the first phase of the study, patients who wish to participate in the open-label extension phase will have the option to continue in the same treatment regimen. For the placebo group, patients will have the option to receive the active treatment during the 12-week open-label phase if the study physician feels it may potentially provide benefits. Similarly, the dose will be titrated up in the placebo group who wants to receive the active drug in the extension program.
The open-label phase is 12 weeks long. For this open-label extension phase the follow-up visits will be done after 4 weeks and 12 weeks of treatment.
CBD in Treating Cancer and Related Symptoms
An Emerging and Alternative Therapy That Still Requires Much Investigation
Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more.
Gagandeep Brar, MD, is a board-certified hematologist and medical oncologist in Los Angeles, California.
Cannabidiol (CBD) is one of many compounds (called cannabinoids) found in the marijuana plant Cannabis sativa. CBD is known for its relaxing and pain-soothing effects.
CBD is non-psychoactive, so it does not give you the classic mind-altering euphoria or “high” felt from using marijuana—that effect comes from the cannabinoid called THC (tetrahydrocannabinol).
While the research is still very early, experts speculate that CBD may play a role in treating cancer, specifically by slowing tumor growth and inducing the death of cancer cells. CBD may also help manage unpleasant symptoms related to cancer and chemotherapy, such as pain, nausea, and vomiting.
CBD and Treating Cancer
There are a number of studies supporting CBD’s potential anti-cancer role—however, the majority are limited to in vitro and animal studies. For example, in various studies, there is evidence that CBD decreases the growth of lung and prostate tumors, provokes the cell death of colon, lung, and brain cancer cells, and reduces the spread (metastasis) of breast cancer.
While promising, large human clinical trials are needed to better understand whether CBD is truly effective in helping to treat cancer. Clinical trials would also allow experts to tease out issues like dosage, interaction with other cancer drugs, and CBD’s safety profile.
As of now, there are only a handful of human studies that have examined CBD’s anti-cancer role.
Here are a few examples:
- In one study of 119 cancer patients (most of the cancers were metastatic and traditional cancer therapies had been exhausted), CBD oil was given on a three day on and three days off schedule. In most of the patients, an improvement in their cancer was noted, such as a decrease in tumor size. No side effects from CBD were reported.
- In a case study, an elderly man with lung cancer refused traditional chemotherapy and radiation for his cancer treatment and instead, self-administered CBD oil. After one month of taking the CBD oil, a computed tomography (CT) scan revealed near-total resolution of his lung tumor along with a reduction in the number and size of chest lymph nodes.
- In another study, two patients with aggressive gliomas (a type of brain tumor) were given CBD capsules in addition to chemoradiation and a multidrug regimen. Both patients had a positive response to the treatment with no evidence of disease worsening for at least two years.
Keep in mind—these studies are extremely small and lack a control group, so no finite conclusions can be drawn from them. Nevertheless, they spark further interest in the possible role of CBD in treating cancer.
CBD and Treating Cancer-Related Symptoms
There is scientific evidence, although limited and not robust, that CBD, THC, or a combination of the two, may be effective in alleviating certain cancer-related symptoms, such as pain, appetite loss, and chemotherapy-induced nausea and vomiting.
For instance, the drugs Marinol (dronabinol) and Cesamet (nabilone), which are synthetic forms of THC, are approved in the United States for treating chemotherapy-induced nausea and vomiting. Research suggests that dronabinol may also improve the taste of food, appetite, sleep, and quality of life in cancer patients.
In addition, a mouth spray that contains both THC and CBD (called Sativex) is being investigated for its role in treating cancer pain (especially nerve-related pain) that is poorly controlled by opioids. The drug is currently not available in the United States, but it is available in Canada for treating advanced cancer pain.
Lastly, research has found that in the general population (so not necessarily patients with cancer), CBD can reduce anxiety and improve sleep quality. This finding is helpful, considering the diagnosis and treatment of cancer is often overwhelming and wrought with fear and worry.
With the potentially emerging use of CBD in treating cancer and/or its related symptoms, there are a few issues to consider.
CBD oil is perhaps the most commonly utilized formulation of CBD, as it’s easy to use and allows for a high dose of consumption. However, CBD comes in many other forms—gummies, tinctures, capsules, vapes, and ointments, to name a few.
Sorting out how to best administer CBD to patients with cancer may prove to be challenging, as various formulations may work or absorb differently.
While research suggests that CBD is generally well-tolerated, we need to more closely examine potential side effects in patients with cancer. In addition, we still do not know the long-term effects of taking CBD, or how it interacts with other medications.
Short-term side effects of CBD may include:
- Reduced or increased appetite
- Weight gain or loss
- Increase in liver enzymes
If CBD is combined with THC (in the form of medical marijuana), other side effects may occur, such as:
- Dry mouth
- Disorientation and confusion
- Loss of balance
While CBD by itself is federally legal (as long as the product is derived from hemp and contains no more than 0.3% THC), marijuana is not (although, it is legal in some states).
CBD is only available by prescription in the United States in the form of a drug called Epidiolex. This drug is used to treat refractory epilepsy.
Due to these legal conundrums, CBD products may not be as tightly regulated as hoped. With that, products that claim they have a certain CBD dosage may actually contain a different amount or even contain traces of THC. This is why it is important to only take CBD under the guidance of your personal healthcare provider.
A Word From Verywell
The prospect of incorporating CBD into cancer care is intriguing but still requires much more investigation. Until then, if you are considering trying CBD (whether you have cancer or not), it’s best to talk out the pros and cons with your healthcare provider.