The claim that Cannabis can cure cancer is all over the Internet. Such promotion is regularly enhanced by announcements of VIPs that they intend to try Cannabis when affected by cancer.

As her back pain turned out to be caused by metastases from her earlier breast cancer, Olivia Newton-John now intends to complete a course of photon radiation therapy along with alternative therapies for improving her quality of life. “I decided on my direction of therapies after consultation with my doctors and natural therapists and the medical team at my Olivia Newton-John Cancer Wellness and Research Centre in Melbourne”, she said. Newton-John had been diagnosed with breast cancer in 1992. At that time, she initially tried acupuncture and homeopathy and only later underwent chemotherapy. Olivia Newton-John’s daughter, Chloe Lattanzi, has stated that her mother would now use cannabis oil to aid in her fight against cancer. Lattanzi owns a marijuana farm and said that her mother would use natural healing remedies plus modern medicine in addition to cannabis oil to help her battle the deadly disease for the second time.

So, how realistic is the assumption that Cannabis does anything for cancer patients? Cannabis produces a resin containing pharmacologically active compounds called cannabinoids. Some cannabinoids are known for their psychoactive properties. Cannabis has therefore been used for medicinal and recreational purposed since ancient times. Today, the recreational use of Cannabis is illegal in many states, including the UK.

The main active cannabinoids are delta-9-THC and cannabidiol (CBD); the latter compound may relieve pain, lower inflammation, and decrease anxiety without causing the “high” of delta-9-THC. Cannabis and cannabinoids have been studied in the laboratory and the clinic for relief of pain, nausea and vomiting, anxiety, and loss of appetite. There also is some evidence that they can alleviate the side-effects of cancer therapies. Two cannabinoids have even been approved by the regulators in some countries for the prevention and treatment of chemotherapy-related nausea and vomiting. Some test tube results have suggested that Cannabis can kill cancer cells. However, there are no clinical trials yet, and therefore not enough evidence exists to recommend that patients use Cannabis as a treatment for cancer.

The possibility that Cannabis might be useful for cancer patients currently attracts much original research. The most recent review states that “favorable outcomes are demonstrated for chemotherapy-induced nausea and vomiting and cancer-related pain, with evidence of advantageous neurological interactions. Benefit in the treatment of anorexia, insomnia and anxiety is also suggested. Short- and long-term side effects appear to be manageable and to subside after discontinuation of the drug. Finally, cannabinoids have shown anti-neoplastic effects in preclinical studies in a wide range of cancer cells and some animal models. Further research is needed before cannabis can become a part of evidence-based oncology practice.”

Similarly, the conclusions by our ‘CAMcancer’ initiative were cautious: ” The antiemetic efficacy of the cannabinoid dronabinol (THC), when compared to standard antiemetics that were in use before the development of 5-HT3 antagonists for chemotherapy-induced nausea and vomiting, has been established in a meta-analysis. The question of whether cannabis-based medicines have a place in the era of modern antiemetic medication, e.g. for patients with refractory nausea and vomiting despite antiemetic prophylaxis according to current standards, remains uncertain but warrants further research. Limited evidence is available to support the use of cannabis-based medicines in the therapy of radiotherapy-related nausea and multifactorial nausea in advanced cancer patients. The use of cannabis-based medicines for appetite loss and other symptoms associated with cancer cachexia is still unclear at present, since trial results have not only varied widely but also been criticised for the methodology employed (including diversity in stages of cachexia in the patients included and possibly too a low dose of THC/medical cannabis). For cancer pain, several randomised controlled trials of cannabis-based medicines in cancer patients with various pain syndromes have indicated an analgesic effect comparable to weak opioids. The role of cannabinoid medicines as add-on medication for pain that is insufficiently relieved by strong opioids is currently being investigated in several clinical studies and has shown some promising results so far.”

So, the evidence suggests that Cannabis might be helpful in the supportive and palliative treatment of cancer by reducing some of the symptoms from which cancer patients may suffer. But there is no good evidence to show that it can change the natural history of any type of cancer. Even with the symptomatic use of Cannabis, we need to consider at least two caveats.

Firstly, we have no good evidence to suggest that Cannabis is significantly more effective than conventional therapies. A Cochrane review, for instance concluded that ” Cannabinoids can lead to an increase in appetite in patients with HIV wasting syndrome but the therapy with megestrol acetate is superior to treatment with cannabinoids. The included studies were not of sufficient duration to answer questions concerning the long-term efficacy, tolerability and safety of therapy with cannabis or cannabinoids. Due to the sparse amount of data it is not possible to recommend a favoured use of cannabis or cannabinoids at this point.”

Secondly, the Cannabis trials tend to be of low quality. Another Cochrane review concluded that “Cannabis-based medications may be useful for treating refractory chemotherapy-induced nausea and vomiting. However, methodological limitations of the trials limit our conclusions and further research reflecting current chemotherapy regimens and newer anti-emetic drugs is likely to modify these conclusions.”

Back to Olivia Newton-John; her case is, I think, telling. It seems that, by initially using alternative therapies instead of conventional treatments for her breast cancer in 1992, she worsened her prognosis. Now that the cancer has returned, she has learnt her lesson and opts for the best conventional oncology can offer her. Yet, her liking for alternative medicine has not disappeared completely. This confirms what I have observed all too frequently: for many of its fans, alternative medicine is a belief system that is largely untouchable by evidence.

30 Responses to Cannabis for cancer?

  • I really believe we need to stop talking about Alternative Therapies. Using the term Complementary Therapies is much more useful – to complete healthcare. My approach to complementary therapies isn’t claiming to cure but to support people with whatever they are going through.

      • There are two kinds of medical treatments. Those that cure, and those that do not cure. Of those that cure, there is no need to discuss ‘alternatives, even though alternatives always exist.

        Of those that do not cure – every one is an alternative treatment that does not cure. Separating them into “clinically tested treatments that don’t cure” and “other treatments that don’t cure” is a waste of time.

        • makes no sense to me

        • Qué?!

        • Hi Tracy
          I am telling you this as a friend, with full respect for your person but not your ideas, or rather your fantasies.
          Your love for medicine and health care is not being returned!
          Find some other interest – you are totally not doing anyone any favour by indulging in incompetent fantasies about health and disease.

          For all it’s worth, you could just as well be fantasizing about the maintenance of Boeing passenger jet engines, it would be just about as useful. I am sorry to say it, but it is sadly clear from your writings that you are totally incompetent with regard to medicine and health issues.

          I suggest you find a little greenhouse and take up horticulture or any other easy pastime where you do not risk misleading people who might get the idea you are an authority on medicine.

          • Thanks for the well thought out, insightful opinion. It is interesting that of three comments two are of the nature of “WTF” and then there’s this. It seems that when we discuss ‘cure’ no one knows what to say, nor what we are talking about. It’s no mystery. Take the time to

            look up the word ‘cure’ in one, or all of these references,

            Webster’s New World Medical Dictionary, Third Edition
            The Oxford Concise Medical Dictionary, Ninth Edition, 2015.
            The Bantam Medical Dictionary, Sixth Edition, 2009.
            Barron’s Dictionary of Medical Terms, Sixth Edition, 2013
            Medical Terminology for Dummies, Second Edition
            Merck Manual of Diagnosis and Therapy, 11th Edition
            Harrison’s Guide to Internal Medicine
            Lange’s Current Medical Diagnosis and Treatment

            and see who doesn’t know what they are talking about.

            The word cure is not defined in any of the above medical dictioinaries. It is defined in only one of the above medical references. Only Merck’s Manual of Diagnosis and Therapy gives a definition of ‘cure’. Where does it appear? In the section titled: “Complimentary and Alternative Medicine”.

            What does that tell us?

          • nothing!

          • @Tracy

            Aha! Now I understand. You’re the chappie who has an obsession with the word ‘cure’ and who bangs on about its meaning as though you’re saying something profound. You’re not.

            I seem to recall you previously stated that, apart from (some) infectious diseases and surgical procedures, no full ‘cure’ is possible. On that occasion I think I replied that many or most infectious diseases have residual sequelae even when the infectious agent has been eliminated: that we all suffer from a terminal, incurable disease called life anyway.

            I don’t have access to the medical dictionaries you list, but I’m not surprised if they don’t define ‘cure’. It’s an everyday word and it doesn’t require your level of in-depth, sustained thinking to make the trivial point that, after any disease, almost no-one ever quite returns to the state they were in prior to the disease. For what it’s worth, the first three hits I obtained by googling ‘medical dictionary’ (,, all do provide comprehensive definitions of ‘cure’. So what?

            It’s interesting you cite the Merck Manual. You cite the 11th edition, but the entire contents of the more recent 19th edition (2011) are available as a PDF download ( That means it can easily be searched for the word ‘cure’ (or the past tense ‘cured’). My count may be subject to about ±2 error (the manual comprises over 4,000 pages!) but — contrary to your claim — the words ‘cure’ or ‘cured’ appear 121 times in the first 2,000 pages, which probably means the whole book contains around 240 mentions.

            The one place I couldn’t find the word in the Merck Manual (19th ed.) is in the chapter on CAM! Well, not quite: “homeopathy is based on the principle that like cures like. A substance that, when given in large doses, causes a certain set of symptoms is believed to cure the same symptoms when it is given in minute doses.” But that hardly counts in context. And, by the way, the Merck Manual spells ‘complementary’ correctly: you might make a note of this.

            Three mentions of ‘cure’ in the Merck Manual I found interesting in the context of the discussion you raise. “In classic Hodgkin lymphoma, disease-free survival 5 yr after therapy is considered a cure.” (p.1156) “Radiation therapy can cure many cancers.” (p.1205), “A thorough explanation of the disorder helps patients understand that, although migraine cannot be cured, it can be controlled, enabling them to better participate in treatment.” (p. 1888)

            You see, Tracy, we all agree with you about the word ‘cure’ and its limitations in everyday speech. But I’d argue that, despite these limitations, “Separating therapies into “clinically tested treatments that don’t cure” and “other treatments that don’t cure” is far from the waste of time you suggest. Approaches to disease management have outcomes on a continuous (and objectively measurable) spectrum. Efficacy measurements, when pre-defined and tested under controlled trial conditions, provide information on the value of a treatment. Those that fall under the heading of CAM have negligible efficacy when properly tested, which is why consumers need to be warned away from them.

          • An interesting response Frank. A few notes… Yes, I often spell complementary incorrectly and it appears I referred to the 11th edition of MERCK, when I meant to say the 2011 edition (the 19th edition). Yes. I have a passion for the word cure. I cannot believe that any medical dictionary can claim to authoritative without including the word cure. I believe that, with a useful definition of cure, we can cure many illnesses, and declare them cured. We can gain a more useful understanding of the concepts of cure and use that understanding to improve health and medical practice as well.

            I don’t know what definition you might choose for the word cure, or for the phrase you use with regards to illnesses caused by parasites “full cure”.

            I have found dozens of definitions of cure in standard dictionaries and other references, often in clear opposition to each other. No wonder there is confusion. I have settled on one, single, clear definition of cure, which I have not seen in any dictionary, medical or non-medical.

            “A cure exists when the cause of an illness has been addressed.”

            I do not use the words ‘true cure’, nor ‘root cause’. They are neither useful nor relevant. A partial cure exists when the cause is partially addressed. Your phrase ‘full cure’ is redundant. A cure is a full cure, or partial.

            re: Merck keyword search. Before Merck’s manual went online, their 11th edition was searchable on the internet. I have stored search results for ‘cure’ in Merck from that time. Most references to cure are words and phrases like ‘incurable’, ‘does not cure’ and the like. I have read EVERY use of cure that was found by the keyword search for Merck 19th edition. I have also reviewed previous versions of Merck, back to 1950. I have also studied the use of the word cure in the original edition of Merck. There is no definition of cure, other than the weak homeopathic reference. This appeared in the 2011 edition, with the appearance of the new section CAM, which did not exist in prior editions. Thanks for the link to PDF – I will find it useful.

            Take care. Use of the word cure in statistical analysis is simply not a cure for any individual illness.

            Statements like “In classic Hodgkin lymphoma, disease-free survival 5 yr after therapy is considered a cure” illustrate this clearly. ‘Considered a cure’ is a statistical cure, not an actual cure. We can ‘consider the patient cured’, but we cannot say they are cured, because cured cannot be proven, only ‘considered’.

            re: “Radiation therapy can cure many cancers.” All cancer cures use the term ‘cure rate’, which is a statistical cure, not an actual cure in any specific case. Although we may claim that radiation ‘cures’ cancers, no doctor would dare to tell a patient that radiation will ‘cure’ their cancer, or that their cancer has been cured – without waiting 5 years.

            Statements in Merck like “although migraine cannot be cured” are simply unsubstantiated speculation, not tested and not provable. They ignore or defy any definition of cure.

            Cure, in many illnesses, is trivial. The cure for scurvy is a healthy diet. If someone has a specific unhealthy diet, they will get scurvy. When the diet is changed, healthed, the illness is cured. The cause has been addressed. If the cause, the unhealthy diet returns, the patient will get a new case of scurvy. Cure is often so trivial that we ignore it. Merck, Lange’s and Harrison’s do not document the ‘cure’ for scurvy. Instead, they suggest treatments with Vitamin C, which cannot cure, because they do not address the cause. These treatments can create a dependency on the ‘medicine’ of Vitamin C, but they cannot cure the illness.

            We tend to look for cures we consider in the hard cases – and then we get confused….

            We need to establish a fundamental understanding of cure and proceed from that point forward. “An illness is cured when the cause has been addressed.”

            to your health, tracy

          • Tracy Kolenchuk,

            Cure, in many illnesses, is trivial. The cure for scurvy is a healthy diet. If someone has a specific unhealthy diet, they will get scurvy. When the diet is changed, healthed, the illness is cured. The cause has been addressed. If the cause, the unhealthy diet returns, the patient will get a new case of scurvy. Cure is often so trivial that we ignore it. Merck, Lange’s and Harrison’s do not document the ‘cure’ for scurvy. Instead, they suggest treatments with Vitamin C, which cannot cure, because they do not address the cause. These treatments can create a dependency on the ‘medicine’ of Vitamin C, but they cannot cure the illness.

            A diet which contains an insufficient level of Vitamin C [aka: ascorbic acid and L-ascorbic acid] is likely to result in the disease named “scurvy”. Therefore: adding Vitamin C to the diet to those who have scurvy is very likely cure them of scurvy; and ensuring that those who do not yet have scurvy maintain a sufficient level of Vitamin C in their diet is very likely to prevent them from succumbing to scurvy.

            The exact means by which a sufficient level of ascorbic acid is maintained in our diets is totally irrelevant[1]. Ascorbic acid is not a “medicine” per se, it is a naturally-occuring chemical in many fruits, some vegetables, and in the liver of many animals.

            It seems that, yet again, your own comment included a more-than-adequate self-refutation of your claims.

            [1] Vitamin C is absorbed by the intestines using a sodium-ion dependent channel.

          • Peter… It’s an interesting theory, that Vitamin C is a cure for scurvy. However, I have looked at many medical reference texts, with regards to scurvy, and I have NEVER seen Vitamin C described as a cure – except in children’s books.

            Perhaps you can help me out with that? References?

            As far as I am aware, this has never been tested in a clinical study, and to do so might be immoral, might not pass approval guidelines. It would require giving the patient scurvy. It would require a clear definition of ‘cured’. And it would require patients to be on a long term diet that does not contain Vitamin C – and supplemental Vitamin C. Vitamin C also comes in several different forms, and presumably each would need to be tested. There are two problems likely to be encountered:
            a) Vitamin C supplementation addresses some of the symptoms of scurvy, but not all of them, or addresses them partially and over time the patient still succumbs to the disease.
            b) The unhealthy diet that causes scurvy also causes other diseases, but over a longer period of time. The disease scurvy normally kills (or is cured by a healthy diet) before these diseases appear.

            In a true test of whether or not Vitamin C cures scurvy, we put the patients in danger. We know the cause, and we know the cure. Vitamin C helps the patient heal, but it has not been proven to cure scurvy.

            If Vitamin C does cure scurvy, then my concept of cure is correct. If Vitamin C cures scurvy, then lack of Vitamin C is the cause of scurvy.

            The cure is to address the cause.

            I simply don’t believe lack of Vitamin C is the most accurate statement of cause of scurvy. We do know that making the diet unhealthy causes scurvy, and that making it healthier cures scurvy. But we cannot extract Vitamin C from the diet without removing other healthy factors. The details are still fuzzy as far as I am aware – and there is little incentive to investigate, because scurvy is not a problem illness.

          • Tracy,

            Likewise, I have never seen an engineering document which states that a puncture repair is a cure for punctured tyres; I have never seen an engineering document which states that replacing the spark plugs in petrol engines is a cure for engine misfire.

            I fully understand the reasons for avoiding the word “cure”, whereas your obsession with the word is tiresomely childish.

          • Hear! Hear! But he won’t get it.

    • On the contrary. Allowing commercial entities and alt-med lobbies to lump together every dodgy and faith-based practice under the sun, disguising its unsuitability for purpose as being “complementary” to normal medicine is absolutely unacceptable. Consumers should not be mislead when buying goods and services, and that needs to apply to what’s health-related as well.

      If the therapy or practice is useful and yields positive outcomes in a consistent manner, soon enough it will drop the “Alternative” prefix. The fact that most do not should be a clear indication of what’s going on.

      • “Consumers should not be mislead when buying goods and services, and that needs to apply to what’s health-related as well.” Totally agreed. The point has been made on this blog over and over again, but it falls on unhearing ears.

      • Oh if only life was so simple…

    • @Julie Tasker

      There are of course several people with the name ‘Julie Tasker’ to be found. This snippet from the website of a “healer”
      by that name ( lists different varieties of „therapies” offered for sale:

      Health Kinesiology incl. tutor and mentor
      Energy Healing including tutor
      Reiki incl. training and attunements
      Indian Head Massage
      Sound Healing Therapy
      Massage Therapy
      Massage in Schools Instructor
      Infant Reflexology Instructor
      Master Energy Colour Healing incl. tutor
      Ear Candling
      Foot Reading
      Meditation: Individual / Group
      Archetypal Consultancy
      Soul Midwifery: Healing into Death and Dying including bereavement. Also helping to cope with other losses.
      Stone Massage
      Yoga: Individual / Group

      Oh dear! I am not going to write down the list of unflattering and harsh words that come to mind when presented with such a list of fake health care acts.

      • Dear Bjorn
        ..if you aren’t an idiot you made a formidable world-class attempt to simulate one.Congratulations!

        What meaning do you expect your delusionally self-important statements of unknowing, inexperienced opinion to have with us? What fantasy do you hold that you would believe that your tiny-fisted tantrums would have more weight than that of a leprous desert rat, spinning rabidly in a circle, waiting for the bite of the snake?

        I have snipped away most of what you wrote, because, well… it didn’t really say anything. Your attempt at constructing a creative flame was pitiful. I mean, really, stringing together a bunch of insults among a load of babbling was hardly effective…
        Sincerely yours..

        • Dear Bjorn
          ..if you aren’t an idiot you made a formidable world-class attempt to simulate one.Congratulations!

          No, believe me, he IS an idiot.

    • And how do you believe your approach ‘supports’ people?

    • They’re two different things.
      Alternative therapies are interventions presented by the people selling them as just that – alternatives to other forms of healthcare.
      This is often dangerous, as it encourages people to eschew effective treatments in favour of ineffective or indeed counterproductive practices/treatments.

      Complementary therapy is what you’re discussing – things like massage, things that smell nice, exercise, music, human interaction, spending time in natural environments/outdoors – anything that doesn’t make a claim to cure or treat a disease, illness or disability, but just lend a helping hand, make people *feel* better and cope with whatever troubles or pains they’re going through.

      Alternative therapy is real and it’s a real problem.

      • Except it’s often a bait-and-switch situation with some “alt” merchants. Customers are lured in, then upsold and “threatened” that the reiki or enemas or baking soda won’t work if conventional treatment is continued.

      • Marianne, your description of “Complementary” therapy makes sense. However, the con artists have turned it into a dirty word by selling junk and fraud in the name of “Complementary ” therapy. They do make the claims to cure,etc, that you stated should not be connected. They have bastardized “Complementary” adjuncts to legitimate therapies for profit and that is a shame.

      • However complementing therapy my interact instead of complementing and reduce efficiency of the treatment or increase side effects/lead to new side effects. So one should rather distinguish between treatments that have significant biological effects and those that have not. Spending time outdoors is nice, as long as the body is not stressed too much – patient must be informed when treatment increases photosensitivity and similar, warned about the need to protecth himself from infections, but that’s it Cannabis oil is a completely different matter. I think it oncologists should know about patient consuming unrefined hemp seed oil in significant quantities (although it is food), but that cannabis oil may be just active enough to cause side effects, thus use must be discussed with doctor.

    • Julie Tasker
      We still though keep coming back to the same problem.
      To what extent do they need the support of Magic and flat- out wing- wang?

  • Julie Tasker quotes Gandhi as saying that perfect harmony is achieved when what you think, say, and do are in agreement.
    I think altmed is nonsense.
    I say it’s nonsense.
    I take the mick out of it.

  • THC and CBD did CURE our lifes ! What more proof do you guys need ???? Talking over and over about it when its so simple! Just start to grow your own medicine and FEEL what THC oil and CBD oil can do for you! From Blood in the fecies because of hemaroids till the most CANCER diseases.. START to make the difference in your life and start taking and making the oil.. Believe me we have been there .. and now we can enjoy life again as its ment to be !!

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