A new study led by a team of Irish, American and Canadian researchers has determined that medical cannabis is a safe and effective treatment for pain caused by cancer when combined with other drugs. The researchers, who are affiliated with the Royal College of Surgeons, Dublin, and the Medical Cannabis Programme in Oncology at Cedars Cancer Centre in Canada, McGill University and Harvard Medical School, concluded that medicinal cannabis is “a safe and effective complementary treatment for pain relief in patients with cancer.”
The study, which was published this week by the peer-reviewed journal BMJ Supportive & Palliative Care, sought to investigate the effectiveness of medical cannabis in reducing pain in cancer patients. The research also examined the effectiveness of medical cannabis in reducing the use of other medications in patients with cancer.
“Our data suggest a role for medicinal cannabis as a safe and complementary treatment option in patients with cancer failing to reach adequate pain relief through conventional analgesics, such as opioids,” the authors of the study wrote.
In their introduction, the researchers note that approximately 38% of cancer patients experience moderate to severe pain. The rate is even higher for some groups of patients, with 55% of patients undergoing anticancer treatment and 66% of patients with advanced, metastatic or terminal disease experiencing pain. Painkillers, often powerful opioids, are the standard treatment for cancer pain, but about a third of patients who use the drugs still experience pain.
To conduct the study, the research team surveyed 358 adult cancer patients over a period of three years to collect real-world data on cancer pain and its treatment. The average age of participants in the study group was 57, and 48% of patients were men. The most common cancer diagnoses were genitourinary, breast and bowel cancers.
About a quarter of the patients were given medical cannabis products rich in THC, 17% were given CBD-dominant formulations and 38% were given a balanced mix of the two products. Every three months for a period of one year, study participants were surveyed and asked how much pain they were experiencing. Patients were also asked how many drugs they took to treat the pain.
Medical Cannabis Reduced Cancer Pain
At three, six and nine months into the study, patients experienced a significant reduction in pain, as measured by factors including pain severity, average pain intensity and overall interference with day-to-day life. Additionally, the research revealed that medical cannabis formulations with a balanced mix of THC and CBD were most effective at reducing the pain experienced by patients during the study.
The researchers also observed a reduction in the number of medications taken by participants during the study period and concluded that medical cannabis was a safe and effective complementary option for patients.
“The particularly good safety profile of [medicinal cannabis] found in this study can be partly attributed to the close supervision by healthcare professionals who authorized, directed, and monitored [the] treatment,” the researchers wrote.
Overall, the medical cannabis products were well tolerated by the patients in the study group. The most commonly reported side effects of the medical cannabis treatments were fatigue and sleepiness, but only by two and three patients, respectively.
The team of researchers recommended further study into using cannabis as a treatment for pain caused by cancer, writing that their “findings should be confirmed through randomized placebo-controlled trials.” They also recommended continued research “particularly to understand any benefits and risks of these medicines for children and young people.”