So, researchers are turning to alternative dosing methods, such as mouth sprays, which deliver a reliable and regulated dose.
Cannabinoids may also have potential in combating the loss of appetite and wasting cachexia experienced by some people with cancer, although so far clinical evidence is lacking.
Cancer Research UK has funded research into cannabinoids, notably the work of Professor Chris Paraskeva in Bristol investigating the properties of cannabinoids as part of his research into the prevention and treatment of bowel cancer.
He has published a number of papers detailing lab experiments looking at endocannabinoids as well as THC, and written a review looking at the potential of cannabinoids for treating bowel cancer. Our funding committees have previously received other applications from researchers who want to investigate cannabinoids but these failed to reach our high standards for funding.
Unfortunately, some scammers are using the email address ukcancerresearchcentre gmail. This is a scam and has nothing to do with Cancer Research UK or our employees, as we wrote about in If you believe you have been a victim of this fraud, please contact the police. Numerous potent cancer drugs have also been developed in this way — purifying a natural compound, improving it and testing it to create a beneficial drug — including taxol , vincristine , vinblastine , camptothecin , colchicine , and etoposide.
Doctors sometimes publish case reports about extraordinary or important observations they have seen in their clinic. There is usually no information about their medical diagnosis, stage of disease, what other cancer treatments they had, or the chemical make-up of their treatment. Robust scientific studies describe the detail of experiments and share the results — positive or negative.
This is vital for working out whether a potential cancer treatment is truly safe and effective, or not. And publishing this data allows doctors around the world to judge the information for themselves and use it for the benefit and safety of their patients.
He is happy to collect individual stories from UK patients and can be contacted by email. If someone chooses to reject conventional cancer treatment in favour of unproven alternatives, including cannabis, they may miss out on treatment that could save or significantly lengthen their life.
They may also miss out on effective symptom relief to control pain or other problems. In the worst cases, an alternative therapy may even hasten death. Although centuries of human experimentation tell us that naturally-occurring cannabinoids are broadly safe, they are not without risks. They can increase heart rate, which may cause problems for patients with pre-existing or undiagnosed heart conditions.
They can also interact with other drugs in the body, including antidepressants and antihistamines. And they may also affect how the body processes certain chemotherapy drugs, which could cause serious side effects. Cannabis is an illegal class B drug in the UK and there are further risks associated with using black market or home-made preparations, particularly cannabis oil, such as toxic chemicals left from the solvents used in the preparation process.
There are also many internet scams by people offering to sell cannabis preparations. We understand the desire to try every possible avenue when conventional cancer treatment fails. But there is little chance that an unproven alternative treatment bought online will help, and it may well harm.
We recommend that cancer patients talk to their doctor about clinical trials that they may be able to join, giving them access to new drugs in a safe and monitored environment.
History shows that the best way to beat cancer is through rigorous scientific research. This approach has helped to change the face of cancer prevention, diagnosis, treatment, leading to survival doubling over the past 40 years. As a research-based organisation, we want to see reliable scientific evidence to support claims made about any cancer treatment, be it conventional or alternative. This is vital because lives are at stake.
Some people may think that a cancer patient has nothing to lose by trying an alternative treatment, but there are big risks. But there are many ways that these compounds can be patented — for example, by developing more effective lab-made versions or better ways to deliver them. But the best chance of ensuring that the potential benefits of cannabinoids — whether natural or man-made — can be brought to patients is through research using quality-controlled, safe, legal, pharmaceutical grade preparations containing known amounts of the drugs.
This requires time, effort and money, which may come from companies or independent organisations such as charities or governments. Because CBD is a potential inhibitor of certain cytochrome P enzymes , highly concentrated CBD oils used concurrently with conventional therapies that are metabolized by these enzymes could potentially increase toxicity or decrease the effectiveness of these therapies.
A number of studies have yielded conflicting evidence regarding the risks of various cancers associated with Cannabis smoking. A pooled analysis of three case-cohort studies of men in northwestern Africa cases and controls showed a significantly increased risk of lung cancer among tobacco smokers who also inhaled Cannabis.
A large, retrospective cohort study of 64, men aged 15 to 49 years from the United States found that Cannabis use was not associated with tobacco-related cancers and a number of other common malignancies. However, the study did find that, among nonsmokers of tobacco, ever having used Cannabis was associated with an increased risk of prostate cancer.
A population-based case-control study of lung cancer patients revealed that chronic low Cannabis exposure was not associated with an increased risk of lung cancer or other upper aerodigestive tract cancers and found no positive associations with any cancer type oral , pharyngeal , laryngeal , lung, or esophageal when adjusting for several confounders, including cigarette smoking.
A systematic review assessing 19 studies that evaluated premalignant or malignant lung lesions in persons 18 years or older who inhaled Cannabis concluded that observational studies failed to demonstrate statistically significant associations between Cannabis inhalation and lung cancer after adjusting for tobacco use. Epidemiologic studies examining one association of Cannabis use with head and neck squamous cell carcinomas have also been inconsistent in their findings. A pooled analysis of nine case-control studies from the U.
Compared with those who never smoked Cannabis , Cannabis smokers had an elevated risk of oropharyngeal cancers and a reduced risk of tongue cancer. These study results both reflect the inconsistent effects of cannabinoids on cancer incidence noted in previous studies and suggest that more work needs to be done to understand the potential role of human papillomavirus infection.
With a hypothesis that chronic marijuana use produces adverse effects on the human endocrine and reproductive systems , the association between Cannabis use and incidence of testicular germ cell tumors TGCTs has been examined. In a study of 49, Swedish men aged 19 to 21 years enrolled in the military between and , participants were asked once at the time of conscription about their use of Cannabis and were followed up for 42 years. Limitations of the study were that it relied on indirect assessment of Cannabis use; and no information was collected on Cannabis use after the conscription-assessment period or on whether the testicular cancers were seminoma or nonseminoma subtypes.
These reports established the need for larger, well-powered, prospective studies , especially studies evaluating the role of endocannabinoid signaling and cannabinoid receptors in TGCTs. During 16 years of follow-up , 89 Cannabis users 0. A comprehensive Health Canada monograph on marijuana concluded that while there are many cellular and molecular studies that provide strong evidence that inhaled marijuana is carcinogenic, the epidemiologic evidence of a link between marijuana use and cancer is still inconclusive.
A cross-sectional survey of cancer patients seen at the Seattle Cancer Care Alliance was conducted over a 6-week period between and Twenty-four percent of patients considered themselves active Cannabis users.
The physical symptoms most commonly cited were pain, nausea, and loss of appetite. Data from 2, Israeli cancer patients who used government-issued Cannabis were collected over a 6-month period to assess for improvement in baseline symptoms. Before treatment initiation, It is difficult to assess from the observational data if the improvements were caused by the Cannabis or the cancer treatment.
Significant symptomatic improvements were noted Because of the observational and uncontrolled nature of this study, the findings are not generalizable, but as the authors suggested, may be useful in designing more rigorous research studies in the future. A retrospective study from Israel of 50 pediatric oncology patients who were prescribed medicinal Cannabis over an 8-year period reported that the most common indications include the following:[ 24 ].
No ongoing clinical trials of Cannabis as a treatment for cancer in humans were identified in a PubMed search. The first published trial of any cannabinoid in patients with cancer was a small pilot study of intratumoral injection of deltaTHC in patients with recurrent glioblastoma multiforme , which demonstrated no significant clinical benefit.
However, The investigators cautioned that this early-phase study was not powered for a survival endpoint. In a consecutive case series study, nine patients with varying stages of brain tumors , including six with glioblastoma multiforme, received CBD mg twice daily in addition to surgical excision and chemoradiation. However, the heterogeneity of the brain tumor patients probably contributed to the findings. Another Israeli group postulated that the anti-inflammatory and immunosuppressive effects of CBD might make it a valuable adjunct in the treatment of acute graft-versus-host disease GVHD in patients who have undergone allogeneic hematopoietic stem cell transplantation.
Clinical data regarding Cannabis as an anticancer agent in pediatric use is limited to a few case reports. Dronabinol , a synthetically produced deltaTHC, was approved in the United States in as an antiemetic to be used in cancer chemotherapy. Nabilone , a synthetic derivative of deltaTHC, was first approved in Canada in and is now also available in the United States. One systematic review studied 30 randomized comparisons of deltaTHC preparations with placebo or other antiemetics from which data on efficacy and harm were available.
Inhaled Cannabis trials were not included. Among all 1, patients included in the review, cannabinoids were found to be more effective than the conventional antiemetics prochlorperazine , metoclopramide , chlorpromazine, thiethylperazine , haloperidol , domperidone, and alizapride. Cannabinoids, however, were not more effective for patients receiving very low or very high emetogenic chemotherapy.
Side effects included a feeling of being high, euphoria , sedation or drowsiness, dizziness, dysphoria or depression, hallucinations , paranoia , and hypotension. Another analysis of 15 controlled studies compared nabilone with placebo or available antiemetic drugs.
A Cochrane meta-analysis of 23 RCTs reviewed studies conducted between and that investigated dronabinol or nabilone, either as monotherapy or as an adjunct to the conventional dopamine antagonists that were the standard antiemetics at that time. The meta-analysis graded the quality of evidence as low for most outcomes. Individuals reported a higher preference for cannabinoids than placebo or prochlorperazine.
There was no difference in the antiemetic effect of cannabinoids when compared with prochlorperazine. In this trial, the primary objective was to assess the response 2 to 5 days after moderately to severely emetogenic chemotherapy. Sixty-one patients were analyzed for efficacy. In the first trial, no antiemetic effect was achieved with marijuana in patients receiving cyclophosphamide or doxorubicin ,[ 43 ] but in the second trial, a statistically significant superior antiemetic effect of inhaled Cannabis versus placebo was found among patients receiving high-dose methotrexate.
One-quarter of the patients reported a favorable antiemetic response to the cannabinoid therapies. This latter study was reported in abstract form in A full report, detailing the methods and outcomes apparently has not been published, which limits a thorough interpretation of the significance of these findings.
Newer antiemetics e. Anorexia , early satiety, weight loss, and cachexia are problems experienced by cancer patients. Such patients are faced not only with the disfigurement associated with wasting but also with an inability to engage in the social interaction of meals. Four controlled trials have assessed the effect of oral THC on measures of appetite, food appreciation, calorie intake, and weight loss in patients with advanced malignancies. The between-group differences were statistically significant in favor of megestrol acetate.
Furthermore, the combined therapy did not offer additional benefits beyond those provided by megestrol acetate alone. The authors concluded that dronabinol did little to promote appetite or weight gain in advanced cancer patients compared with megestrol acetate.
In trials conducted in the s that involved healthy control subjects, inhaling Cannabis led to an increase in caloric intake , mainly in the form of between-meal snacks, with increased intakes of fatty and sweet foods. Despite patients' great interest in oral preparations of Cannabis to improve appetite, there is only one trial of Cannabis extract used for appetite stimulation. In a RCT, researchers compared the safety and effectiveness of orally administered Cannabis extract 2.
Results demonstrated that although these agents were well tolerated by these patients, no differences were observed in patient appetite or quality of life among the three groups at this dose level and duration of intervention. No published studies have explored the effect of inhaled Cannabis on appetite in cancer patients. Through the study of cannabinoid receptors , endocannabinoids, and synthetic agonists and antagonists, the mechanisms of cannabinoid-induced analgesia have been analyzed.
Cancer pain results from inflammation , invasion of bone or other pain-sensitive structures, or nerve injury. When cancer pain is severe and persistent, it is often resistant to treatment with opioids. Two studies examined the effects of oral deltaTHC on cancer pain. The first, a double-blind, placebo-controlled study involving ten patients, measured both pain intensity and pain relief. In a follow-up , single-dose study involving 36 patients, it was reported that 10 mg doses of deltaTHC produced analgesic effects during a 7-hour observation period that were comparable to 60 mg doses of codeine, and 20 mg doses of deltaTHC induced effects equivalent to mg doses of codeine.
Another study examined the effects of a plant extract with controlled cannabinoid content in an oromucosal spray. In a multicenter, double-blind, placebo-controlled study, the THC:CBD nabiximols extract and THC extract alone were compared in the analgesic management of patients with advanced cancer and with moderate-to-severe cancer-related pain.
The researchers concluded that the THC:CBD extract was efficacious for pain relief in advanced cancer patients whose pain was not fully relieved by strong opioids. These studies provide promising evidence of an adjuvant analgesic effect of THC:CBD in this opioid-refractory patient population and may provide an opportunity to address this significant clinical challenge.
An observational study assessed the effectiveness of nabilone in advanced cancer patients who were experiencing pain and other symptoms anorexia, depression, and anxiety.
The researchers reported that patients who used nabilone experienced improved management of pain, nausea, anxiety, and distress when compared with untreated patients. Nabilone was also associated with a decreased use of opioids, nonsteroidal anti-inflammatory drugs , tricyclic antidepressants , gabapentin , dexamethasone , metoclopramide, and ondansetron.
Animal studies have suggested a synergistic analgesic effect when cannabinoids are combined with opioids. The results from one pharmacokinetic interaction study have been reported. In this study, 21 patients with chronic pain were administered vaporized Cannabis along with sustained-release morphine or oxycodone for 5 days. These findings should be verified by further studies before recommendations favoring such an approach are warranted in general clinical practice.
Neuropathic pain is a symptom cancer patients may experience, especially if treated with platinum-based chemotherapy or taxanes. Two RCTs of inhaled Cannabis in patients with peripheral neuropathy or neuropathic pain of various etiologies found that pain was reduced in patients who received inhaled Cannabis , compared with those who received placebo.
Some limitations of this study were its retrospective design and that documentation of Cannabis use was qualitative, not quantitative.
A randomized, placebo-controlled, crossover, pilot study of nabiximols in 16 patients with chemotherapy-induced neuropathic pain showed no significant difference between the treatment and placebo groups. A responder analysis, however, demonstrated that five patients reported a reduction in their pain of at least 2 points on an point scale, suggesting that a larger follow-up study may be warranted.
One real-world randomized controlled trial explored Cannabis use in patients with advanced cancer who received care in a community oncology practice setting screened; 30 randomized; 18 analyzed.
The EC group had stable opioid usage compared with the DC group who had an increase in opioid usage during the 3-month study period. Overall, there were no significant changes in quality of life or symptom scores between the groups, with no overall Cannabis -related adverse events. Limitations included a variety of cancer types and no consistent use of Cannabis products different Cannabis products were dispensed during the study period.
In a small pilot study of analgesia involving ten patients with cancer pain, secondary measures showed that 15 mg and 20 mg doses of the cannabinoid deltaTHC were associated with anxiolytic effects.
A small placebo-controlled study of dronabinol in cancer patients with altered chemosensory perception also noted increased quality of sleep and relaxation in THC-treated patients.
Patients often experience mood elevation after exposure to Cannabis , depending on their previous experience. In a five-patient case series of inhaled Cannabis that examined analgesic effects in chronic pain, it was reported that patients who self-administered Cannabis had improved mood, improved sense of well-being, and less anxiety. Another common effect of Cannabis is sleepiness.
Seventy-four patients with newly diagnosed head and neck cancer self-described as current Cannabis users were matched to 74 nonusers in a Canadian study investigating quality of life using the EuroQol-5D and Edmonton Symptom Assessment System instruments. Cannabis users were also less tired, had more appetite, and better general well-being.
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria.
General information about clinical trials is also available. Because cannabinoid receptors , unlike opioid receptors, are not located in the brainstem areas controlling respiration, lethal overdoses from Cannabis and cannabinoids do not occur. Although cannabinoids are considered by some to be addictive drugs , their addictive potential is considerably lower than that of other prescribed agents or substances of abuse.
Withdrawal symptoms such as irritability, insomnia with sleep electroencephalogram disturbance, restlessness, hot flashes , and, rarely, nausea and cramping have been observed. However, these symptoms appear to be mild compared with withdrawal symptoms associated with opiates or benzodiazepines , and the symptoms usually dissipate after a few days.
Unlike other commonly used drugs, cannabinoids are stored in adipose tissue and excreted at a low rate half-life 1—3 days , so even abrupt cessation of cannabinoid intake is not associated with rapid declines in plasma concentrations that would precipitate severe or abrupt withdrawal symptoms or drug cravings. Cannabidiol CBD is an inhibitor of cytochrome P isoforms in vitro.
Because many anticancer therapies are metabolized by these enzymes , highly concentrated CBD oils used concurrently could potentially increase the toxicity or decrease the effectiveness of these therapies.
Since Cannabis smoke contains many of the same components as tobacco smoke, there are valid concerns about the adverse pulmonary effects of inhaled Cannabis. A longitudinal study in a noncancer population evaluated repeated measurements of pulmonary function over 20 years in 5, men and women whose smoking histories were known. A small study investigated the effect of Cannabis tea in 24 patients who received irinotecan or docetaxel.
An Israeli retrospective observational study assessed the impact of Cannabis use during nivolumab immunotherapy. In a multivariate model, Cannabis was the only significant factor that reduced the response rate to immunotherapy There was no difference in progression-free survival or overall survival.
A subsequent prospective observational study from the same investigators followed patients with metastatic cancers initiating immunotherapy. Over half of the patients in each group had stage IV non-small cell lung cancer. In this analysis, the median time to tumor progression was 3. The investigators postulated that this finding may be related to the possible immunosuppressive effects of Cannabis and concluded that Cannabis consumption should be carefully considered in patients with advanced malignancies who are treated with immunotherapy.
To assist readers in evaluating the results of human studies of integrative, alternative, and complementary therapies for people with cancer , the strength of the evidence i. To qualify for a level of evidence analysis , a study must:. Separate levels of evidence scores are assigned to qualifying human studies on the basis of statistical strength of the study design and scientific strength of the treatment outcomes i.
The resulting two scores are then combined to produce an overall score. An overall level of evidence score cannot be assigned to cannabinoids because there has been insufficient clinical research. For an explanation of possible scores and additional information about levels of evidence analysis of Complementary and Alternative Medicine CAM treatments for people with cancer, refer to Levels of Evidence for Human Studies of Integrative, Alternative, and Complementary Therapies.
Add image. Top cast Edit. Peter Coyote Narrator as Narrator voice. Storyline Edit. Discover the truth about this ancient medicine as world renowned scientists in the field of cannabinoid research explain and illustrate their truly mind-blowing discoveries.
Most medical doctors are not aware of this information and its implications for prevention and treatment. If we need more evidence that our current policy on cannabis is counterproductive and foolish, here it is. Not Rated. Add content advisory. Did you know Edit. Quotes [first lines] Narrator : It's been used by human beings since the dawn of time.
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