By Pat Anson, PNN Editor

Good news for patients suffering from cancer pain or side effects from cancer treatment. Two new studies found that medical cannabis helps relieve cancer pain, and offer some lessons to non-cancer patients about which cannabis products might work best for them.

The first study involved 358 adult cancer patients enrolled in a cannabis registry created by the Quebec Medical College. The patients were being treated for a variety of different cancers and were referred to the registry by their doctors. The primary complaint of most was pain (72%), with others experiencing symptoms such as nausea, anorexia, weight loss, anxiety and insomnia.

Participants were assigned to one of three groups, using cannabis products that were high in tetrahydrocannabinol (THC), high in cannabidiol (CBD), or a balanced blend of THC and CBD. The cannabis was ingested orally, through inhalation or a combination of the two. Patients were monitored and assessed every three months for a year.

The study findings, published in the journal BMJ Supportive & Palliative Care, show that pain levels dropped significantly after 3, 6 and 9 months, with pain slightly worsening after 12 months. Patients using balanced THC-CBD products reported the most pain relief, and many were able to reduce their use of opioids and other medications.

A small percentage of patients suffered adverse events from cannabis, such as sleepiness, dizziness and fatigue. Only 5 patients had side effects so severe that they stopped using cannabis.

Researchers concluded that medical cannabis should have a role as a complimentary pain management option in cancer patients who don’t get adequate relief from conventional analgesics.

“We found MC (medical cannabis) to be a safe and effective treatment option to help with cancer pain relief. THC:CBD balanced products appear to perform better as compared with THC-dominant and CBD-dominant products. Furthermore, we observed consistent decreases in medication burden and opioid use in our patient population,” researchers said.

Less Pain = Better Cognition

The second study, by researchers at University of Colorado Boulder, involved 25 cancer patients being treated by oncologists at the CU Anschutz Medical Campus. The patients’ pain levels, sleep patterns, cognition and reaction times were assessed at the start of the study; and they were asked to select edible products from a cannabis dispensary, such as chocolates, gummies, tinctures and baked goods containing different ratios of THC and CBD.

After just two weeks of regular use, patients reported less pain, better sleep, and the unexpected benefit of improved cognition – they were able to think more clearly.

“When you’re in a lot of pain, it’s hard to think,” said senior author and cancer survivor Angela Bryan, PhD, a professor of psychology and neuroscience at CU Boulder. “We found that when patients’ pain levels came down after using cannabis for a while, their cognition got better.”

The improved cognition didn’t happen right away. Patients who used edibles rich in THC got high from it and their cognition initially decreased. But after a few days of regular cannabis consumption, a new pattern emerged. Patients reported improvements in pain, sleep and cognitive function, including reaction times.

“We thought we might see some problems with cognitive function,” said Bryan. “But people actually felt like they were thinking more clearly.”

Patients who ingested edibles high in CBD reported bigger improvements in sleep quality and pain intensity.

Bryan’s study, published in the journal Exploration in Medicine, is one of the first to assess the efficacy of cannabis purchased at dispensaries — rather than less potent government supplied cannabis or synthetic cannabis medications that are primarily used to treat nausea.

Bryan had just begun studying medical cannabis in 2017, when she was diagnosed with breast cancer. After surgery and chemotherapy, she looked to cannabis for pain relief as an alternative to opioids. Neuropathic pain is a common side effect from chemotherapy.

Bryan used her own customized regimen of potent THC products when pain was intense and took mostly CBD products when the pain was more manageable. She was not completely pain-free, but she didn’t take a single opioid during treatment. She hopes others will learn from her experience.

“I was extremely lucky because I had some knowledge about this. Most patients don’t,” Bryan said. “People are open to trying whatever they think might be useful, but there's just not much data out there to guide them on what works best for what.”

As many as 40% of U.S. cancer patients use cannabis, but only a third of doctors feel comfortable advising them about it.