One in eight women in the United States will be diagnosed with breast cancer in her lifetime, according to the National Breast Cancer Foundation. Just this year, approximately 316,950 women and 2,800 men will be diagnosed with invasive breast cancer.
Some breast cancer patients find relief from symptoms and treatment side effects using medical cannabis, but there is still a lot we don’t know about the potential benefits and side effects of cannabis products.
Cannabis contains chemicals called cannabinoids. The most common types are Tetrahydrocannabinol or THC which is a psychoactive compound and can have hallucinogenic effects in high doses, and CBD (cannabidiol) which provides pain relief, but doesn't give the person a feeling of "being high."
Different forms of cannabis contain different combinations of cannabinoids and therefore varying levels of potency. Marijuana contains larger amounts of THC while Hemp is mostly CBD. Most medical marijuana products are a combination of CBD and THC.
Medical cannabis can be consumed by smoking, vaping, eating “edibles” and take taking capsules, oils, or tinctures by mouth.
The medical conditions medical marijuana is currently approved for include: Amyotrophic lateral sclerosis, anxiety disorders, autism, cancer, Chronic Hepatitis C, Crohn's disease, damage to the nervous tissue of the central nervous system and associated neuropathies, Dyskinetic and spastic movement disorders, epilepsy, glaucoma; HIV / AIDS, Huntington's disease, inflammatory bowel disease, intractable seizures, multiple sclerosis, neurodegenerative diseases, neuropathies and chronic pain. You can find the full list of approved conditions at pa.gov/agencies/health/programs/medical-marijuana-patients.html.
Metro Philadelphia talked to Dr. Brooke Worster, M.D., Chief Medical Consultant at Ethos Cannabis, Director of Supportive Oncology at Jefferson Health, about what breast cancer patients and their families should know about medical cannabis.
Worster said it can best help breast cancer patients with difficulties falling and staying asleep and aches and pain; however, she emphasized that cannabis is not a cure or treatment for the cancer itself, despite what some preclinical studies suggest.
You should never use medical cannabis in place of proven cancer treatments like radiation and chemotherapy, she stressed.
“We do not have evidence that it actually treats cancer. Very preliminary evidence in petri dishes suggests it can slow down cell reproduction and sometimes this gets overstated.” Worster said.
Some patients also find medical cannabis can help relieve the nausea, vomiting and loss of appetite caused by chemotherapy and with stress and anxiety.
One 2024 study found that adding oral cannabis to anti-nausea medicine can provide better results for patients receiving chemotherapy. Three synthetic THC medicines are FDA-approved for treating nausea and vomiting caused by chemotherapy: Cesamet, Marinol and Syndros.
Worster said patients with cancer in the lungs shouldn’t smoke or vape cannabis. Also, people with a heart condition or a history of heart attacks are at greater risk of having a heart attack from marijuana use.
Reported side effects of marijuana, which has higher amounts of THC, include increased heart rate, low blood pressure, dizziness and falling, tiredness, fatigue, sleepiness, hallucinations and paranoia.
It is important to note that marijuana in high quantities can be addictive and can lead to depression and anxiety.
Cannabis hyperemesis syndrome is a condition where you experience nausea, vomiting and stomach pain whenever you consume cannabis. It usually affects long-term users who have been consuming cannabis since they were adolescents.
While CBD has fewer side effects than marijuana, some users have reported drowsiness and fatigue, dry mouth, diarrhea and reduced appetite.
Cannabis is also known to interact with certain drugs. It is important to talk to your doctor about your usage before and during treatment.
In one review of preclinical or in-vivo studies, researchers found that cannabinoids slowed down the proliferation and migration of cancer cells. They also found that treating mice with breast cancer with THC and a CB2 receptor agonist slowed tumor growth.
One of the most recent studies suggests that CBD may actually be able to act on the breast cancer cells themselves, but that more clinical data is needed to confirm this. Limitations in study design and standardized protocols need to be addressed first.
Overall, the experts say there isn’t enough evidence to suggest that cannabis can be used as a treatment for breast cancer, but it can be helpful in relieving some symptoms.
Worster said, “It is important for breast cancer patients and their families to know that medical cannabis is there as an option, and to feel empowered to ask how to get guidance on it.”
Patients, caregivers, and healthcare practitioners can register and participate in the medical marijuana programs in Pennsylvania and New Jersey.
