After tracking the progress of about 20 patients with brain cancer who used cannabis, a neuro-oncologist found that the substance caused them no harm, had few side effects and did not interfere with conventional treatments.
While Blondin has not yet been able to draw conclusions about whether cannabis has extended overall survival in the patients, he did hear from some that it has improved their quality of life.
Director of neuro-oncology services at Associated Neurologists of Southern Connecticut, in Fairfield, and medical director of the St. Vincentâ€™s Brain Tumor Center, in Bridgeport, the doctor reported his methods and observations in a poster presented Nov. 17 at the 22nd Annual Meeting and Education Day of the Society for Neuro-Oncology, in San Francisco.
â€śThe patients mostly feel pretty good,â€ť he said. â€śIt does not make them any worse. Besides fatigue if they take too much, which quickly reverses, there are no side effects. Itâ€™s not common amongst neuro-oncologists now, but itâ€™s part of the routine care I provide in my practice.â€ť
Blondin shared his results because cannabis use among brain cancer patients is a scarcely studied but growing phenomenon, with one Facebook group about cannabis oil treatment for people who have glioblastoma boasting 9,000 members. Since cannabis isnâ€™t FDA-approved or regulated and thereâ€™s little or no instruction about its use in medical schools, â€śneuro-oncologists need to know about it and understand the treatment potential, pitfalls and side effects,â€ť he said. â€śTalk about it with your patients, because patients are doing it.â€ť
Medical marijuana is legal in Connecticut and in the majority of American states, and Blondin works with a state-run dispensary to get prescriptions for his patients.
â€śI mention the option to patients to use with standard treatment when diagnosed, and see if theyâ€™re interested, or if their families want them to try it,â€ť he said. He advises against cannabis if the patient has a history of addiction or psychiatric or cognitive disabilities, but considers most he treats to be eligible.
When patients are interested, Blondin registers them with the state, which allows them to buy cannabis at Connecticut dispensaries.
â€śThey grow it all, and manufacture the cannabis oil, in Connecticut, and the quality control is good,â€ť he said. â€śI know how many milligrams patients are taking. Iâ€™ve developed a relationship with the pharmacist at one dispensary, and they know what I want to do. Weâ€™re all learning together.â€ť
Working Through Challenges
One challenge is that no particular dose has been established as effective for patients with brain cancer, Blondin said.
Patients who take the drug palliatively are typically looking to ease symptoms Âľ including headaches, nausea, vomiting, gastrointestinal issues, anxiety, lack of appetite and insomnia. These patients usually find it most effective to smoke cannabis oil, often using vaporizer pens, Blondin said. Others use cannabis oil in the hopes that it will kill cancer cells, because there is some evidence in mouse models that cannabinoids, taken in combination with the standard treatment Temodar (temozolomide), can increase the effectiveness of the chemotherapy, he said. The oil comes in foil packets with syringes that are used to inject the substance into capsules, which are then swallowed. Another alternative is a sublingual spray.
In studies, mice were given 10 mg/kg of the oil, so thatâ€™s the highest dose Blondin recommends. He suggests that, if patients are experiencing fatigue, they are taking too much. The best way for these patients to find their ideal dose, he said, is to cut back on the amount of oil theyâ€™re taking and increase it every two days until they begin to experience fatigue.
Another complicating factor is that it isnâ€™t entirely clear which ingredients in cannabis might be helpful for patients with brain cancer: THC, CBD or a combination, Blondin said.
Patients who take THC experience a high, which may be acceptable for those looking to ease insomnia or anxiety, he said. On the other hand, he said, CBD, which is non-psychoactive, also seems to work well for anxiety. In addition to consulting with Blondin, patients can choose their treatments and doses by doing research online or on social media, seeking advice from the pharmacist at a local dispensary or checking with a private consulting firm such as Green Health Consultants, the doctor said.
A final additional challenge is that cannabis represents an out-of-pocket cost for patients, Blondin said.
His study tracked three groups of patients: low users, who basically registered for cannabis at the behest of their caregivers, but then never tried it; palliative users; and therapeutic users.
Tracked were five astrocytoma patients, four of whom used palliatively and one therapeutically; three anaplastic astrocytoma patients, one of whom used palliatively and two therapeutically; and 12 glioblastoma patients, including three low-use patients, two who used palliatively and seven who used therapeutically. Some started earlier in the course of their treatment than others. Blondin authorized the first of his patients to use medical marijuana on March 3, 2014, and that was when he initiated his effort to track outcomes. In all, he approved four patients to use cannabis in 2014, six in 2015, four in 2016 and six so far this year. His data cutoff date for the study presented at SNO was June 12, 2017.
All of his patients who are taking cannabis palliatively have reported that it is effective, Blondin said. Among those using cannabis therapeutically, he said, all seven glioblastoma patients were alive at data cutoff; their cannabis use had ranged from two to 30 months.
Blondin intends to keep studying the issue and hopes that cannabis will be investigated in clinical trials as a therapy for this population. He is considering crowdsourcing with patients, especially long-term survivors of brain cancer who use cannabis, to learn more about the doses and methods of delivery they choose for themselves, and what they have found effective. â€śI would want to have other doctors who are interested pool their data,â€ť he added, â€śso we can find out whatâ€™s going on.â€ť