We’ve long known about the link between cannabis and cancer, with the plant holding the potential to lessen symptoms related to cancer treatment and reports that THC and other cannabinoids may slow growth or kill certain types of cancer cells.
Now, a University of Buffalo (UB) researcher hopes to further expand our collective knowledge around cannabis and its effect on cancer treatment.
UB College of Arts and Sciences Associate Professor of Psychology Rebecca Ashare, PhD, received a $3.2 million grant from the National Cancer Institute to investigate how cannabis use affects patients who receive immunotherapy, according to a UB press release.
This advancing cancer treatment is designed to elicit or amplify an immune response, using substances made in the body or a lab to boost the immune system, helping the body to find and destroy cancer cells.
Nearly 44% of cancer patients, with 20 different tumor types, receive this therapy — specifically one form of the therapy involving immune checkpoint inhibitors (ICIs), according to the release. These immune checkpoints are a normal part of our immune systems, which govern the immune response to prevent destruction of healthy cells.
Cannabis use in cancer patients is common, with up to 40% using cannabis for symptom management during and after their treatments per the UB release. Despite the widespread use of cannabis for cancer, Ashare notes that there is still a lack of thorough research investigating the efficacy of using cannabis for this purpose.
“There are virtually no long-term studies evaluating its potential benefits and harms for persons treated with immunotherapy for cancer, despite cancer and its treatments being qualifying conditions in most of the 37 states and Washington, D.C., that have legalized adult use or medical cannabis,” Ashare said. “There are reports of benefits surrounding pain relief, improving mood and curbing sleep deprivation, but there is also evidence of physical, cognitive and mental harms, including cannabis use disorder.”
ICIs are commonly used as a form of cancer immunotherapy frontline treatment. They typically have fewer side effects than chemotherapy, and patients can be on the treatment for longer.
Ashare cited the anti-inflammatory properties of cannabis, which can suppress immune function. This is often a positive, except when the immune system is fighting cancer, Ashare said, citing the potential concerns that cannabis could reduce the efficacy of immunotherapy.
“The demand for evidence is clear and this project represents an important first step in that process as both immunotherapy and cannabis use are becoming more widespread therapeutic options in oncology, accepted by many patients and physicians,” Ashare said.
UB will be joined by Thomas Jefferson University and Oregon Health and Science University to recruit participants for the three-site, 12-month observational study, specifically looking at the benefits and harms of cannabis use over time among cancer patients treated with immunotherapy.
Each site will recruit 450 participants undergoing ICI immunotherapy for cancer treatment; half of the participants will be cannabis users and the other half will be non-users. Participants will not be randomized, and they will use their own cannabis products. Researchers will look at benefits and harms through medical records, patient outcomes and blood samples six different times over a one-year period.
The project will include the largest group of cancer patients in the country investigating the use of cannabis in relation to cancer treatment.
Another aim of the grant is to look at the role of neighborhood disadvantage — or the lack of access to economic and social sources that may result in a detrimental effect on health outcomes beyond individual characteristics.
“We want to see if access to cannabis reduces health disparities,” Ashare said.
Ashare has worked with cannabis in relation to cancer treatment for years, previously investigating how cannabis use may enable patients to reduce or eliminate opioid use for pain management. During that research, she noticed there was plenty of literature on the potential benefits of cannabis use but less surrounding its potential adverse effects. She’s now looking to fill that gap.
“We have a strong multidisciplinary team with expertise in cancer symptom management, medical cannabis, health equity, oncology, immunology, and substance misuse,” Ashare added. “Overall this research will have a sustained impact on the science of cancer symptom management and ultimately improve patient care and safety.”
