If you or a loved one have cancer, you’re probably considering every option for easing side effects of treatments like chemotherapy and radiation. Many ask about the connection between cancer side effects and medical marijuana.
While this plant has a reputation as a recreational drug, a growing body of research suggests that it may have potential health benefits, too. Here’s what to keep in mind.
Learn more about integrative oncology on the UPMC Hillman Cancer Center website.
Medical Marijuana and Cancer Care
There are three recognized species of marijuana:
The different strains appear to have varying physiological and psychological effects. The plant also contains about a hundred different compounds, called cannabinoids, which appear to activate specific receptors throughout the human body.
The best known of these compounds is delta-9-tetrahydrocannabinol, or THC, which is believed to what gives cannabis its psychoactive effects. Another compound, cannabidiol, is a nonpsychoactive cannabinoid that shows promise: Studies suggest that it helps protect against nerve-related pain, has antiseizure properties, and may inhibit the proliferation of cancer cells.
People with cancer may use cannabis for a variety of symptoms. The most robust evidence is in the areas of appetite, nausea and vomiting, and pain.
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Appetite and Marijuana Use
In 1986, the Food and Drug Administration first licensed and approved dronabinol — a prescription drug that contains synthetic THC — to treat nausea and vomiting associated with chemotherapy.
Evidence to support the use of dronabinol, however, is mixed. One clinical trial by Cantonal Hospital in Switzerland looked at an extract of cannabis and dronabinol in 243 people with cancer-related anorexia-cachexia syndrome and found that neither was better than a placebo pill at affecting appetite.
Another study, published in the Journal of Clinical Oncology, found that of 469 people with advanced cancer who received the drug megestrol acetate, dronabinol, or both, those who took megestrol had significantly greater increases in both weight and appetite. Combining dronabinol with megestrol seemed to offer no additional benefit compared with megestrol alone, suggesting that marijuana and cancer side effects might not always be linked.
Yet other research suggests that smoking real marijuana (rather than taking it as a synthetic medication) may improve appetite.
For instance, one study of six healthy men by Johns Hopkins University School of Medicine in the 1980s found that those who smoked marijuana that contained THC also consumed 40 percent more calories than their peers (hence, the munchies).
Marijuana for Nausea and Vomiting
The National Comprehensive Cancer Network recommends cannabinoids for the treatment of chemotherapy-related nausea and vomiting when conventional measures have failed. This advice is based on numerous studies that show THC is more effective than prescription antinausea drugs.
Marijuana for Pain Management
A growing body of evidence suggests that cannabinoids have pain-relieving effects. Research led by the University of Toronto indicates that they may relieve cancer pain as well as or better than other medicines, but there aren’t enough studies to draw definitive conclusions.
Because government regulations make it challenging for researchers to investigate the health effects of marijuana, the current clinical evidence for cannabis and cancer may not accurately reflect its potential real-life benefits.
RELATED: Coping with Chemo Side Effects
Cancer Treatment and Cannabis
Perhaps the most exciting area of current research involves the anticancer properties of cannabinoids. According to the National Cancer Institute, a number of studies suggest that these compounds can inhibit the growth of skin, uterine, breast, stomach, thyroid, colorectal, pancreatic, brain, and prostate cancer cells.
Unlike most conventional chemotherapy drugs, cannabinoids appear to kill tumor cells without adversely affecting surrounding normal cells. This could be great news for people interested in the link between cannabis and cancer.
The Big Picture on Medical Marijuana
Pharmaceuticals used for appetite, nausea, and pain, as well as insomnia, neuropathy, and fatigue often produce unwanted side effects. Cannabis may control symptoms with fewer adverse effects.
For many people, having one form of treatment that can target multiple symptoms at once is reason enough to consider cannabis.
It’s worth restating: The current clinical evidence for cannabis and cancer is limited, because marijuana has historically been considered illegal.
But many states, including Pennsylvania, have adopted medical marijuana legislation and processes.
Pennsylvania’s Medical Marijuana Program
Pennsylvania’s medical marijuana program provides access to medical marijuana for patients with specific medical conditions, one of which including cancer and remission therapy. Getting medical marijuana through Pennsylvania’s medical marijuana program involves four basic steps:
- Register for the program through the Medical Marijuana Registry.
- Have a physician certify that you have one of the medical conditions that qualify for medical marijuana. Physicians who recommend medical marijuana in Pennsylvania are required to register with the Department of Health. The Registry has a list of approved physicians if your current physician is not registered with the Department of Health.
- Pay for a medical marijuana ID card.
- Get medical marijuana from an approved dispensary in Pennsylvania.
Medical marijuana caregivers
When completing your application in the PA Medical Marijuana Registry, you can designate up to two caregivers to assist you in obtaining medical marijuana. Caregivers can be a spouse, a parent, or even a friend. Patients under the age of 18 are required to have a caregiver. Caregivers also have to register for the medical marijuana program. All caregivers must complete a background check before being approved. Jump to Become a Medical Marijuana Caregiver to find more information on how to register.
The Wellness and Integrative Oncology Program at UPMC Hillman Cancer Center
The Wellness and Integrative Oncology Program at UPMC Hillman Cancer Center is committed to providing patients for whom the benefits of using medicinal marijuana outweigh any potential risks with the clearest and most up to date information.
Our philosophy is to guide patients as collaborative participants in whole-person care. We are poised to assist patients with the exciting potential of cannabis in cancer care and your best interests in mind.
Editor's Note: This article was originally published on , and was last reviewed on .
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About UPMC Hillman Cancer Center
When you are facing cancer, you need the best care possible. UPMC Hillman Cancer Center provides world-class cancer care, from diagnosis to treatment, to help you in your cancer battle. We are the only comprehensive cancer center in our region, as designated by the National Cancer Institute. We have more than 70 locations throughout Pennsylvania, Ohio, and New York, with more than 200 oncologists – making it easier for you to find world-class care close to home. Our internationally renowned research team is striving to find new advances in prevention, detection, and treatment. Most of all, we are here for you. Our patient-first approach aims to provide you and your loved ones the care and support you need. To find a provider near you, visit our website.