A comprehensive assessment of the benefits of medical cannabis for cancer-related pain found that for most oncology patients, pain measures improved significantly, other cancer-related symptoms also decreased, the consumption of painkillers was reduced, and the side effects were minimal. Published in Frontiers in Pain Research, these findings suggest that medicinal cannabis can be carefully considered as an alternative to the pain relief medicines that are usually prescribed to cancer patients.

Pain, along with depression, anxiety, and insomnia, are some of the most fundamental causes of oncology patient's disability and suffering while undergoing treatment therapies, and may even lead to worsened prognosis.

"Traditionally, cancer-related pain is mainly treated by opioid analgesics, but most oncologists perceive opioid treatment as hazardous, so alternative therapies are required," explained author David Meiri, assistant professor at the Technion Israel Institute of Technology.

"Our study is the first to assess the possible benefits of medical cannabis for cancer-related pain in oncology patients; gathering information from the start of treatment, and with repeated follow-ups for an extended period of time, to get a thorough analysis of its effectiveness."

Need for alternative treatment

After talking to several cancer patients, who were looking for alternative options for pain and symptom relief, the researchers were keen to thoroughly test the potential benefits of medicinal cannabis.

"We encountered numerous cancer patients who asked us whether medical cannabis treatment can benefit their health," said co-author Gil Bar-Sela, associate professor at the Ha'Emek Medical Center Afula. "Our initial review of existing research revealed that actually not much was known regarding its effectiveness, particularly for the treatment of cancer-related pain, and of what was known, most findings were inconclusive."

The researchers recruited certified oncologists who were able to issue a medical cannabis license to their cancer patients. These oncologists referred interested patients to the study and reported on their disease characteristics.

"Patients completed anonymous questionnaires before starting treatment, and again at several time points during the following six months. We gathered data on a number of factors, including pain measures, analgesics consumption, cancer symptom burden, sexual problems, and side effects," said Bar-Sela.

Improved symptoms

An analysis of the data revealed that many of the outcomes measures improved, with less pain and cancer symptoms. Importantly, the use of opioid and other pain analgesics reduced. In fact, almost half of the patients studied stopped all analgesic medications following six months of medicinal cannabis treatment.

"Medical cannabis has been suggested as a possible remedy for appetite loss, however, most patients in this study still lost weight. As a substantial portion were diagnosed with progressive cancer, a weight decline is expected with disease progression," reported Meiri.

He continued: "Interestingly, we found that sexual function improved for most men, but worsened for most women."

Meiri would like future studies to dig deeper and look at the effectiveness of medicinal cannabis in in different groups of cancer patients.

"Although our study was very comprehensive and presented additional perspectives on medical cannabis, the sex, age, and ethnicity, as well as cancer types and the stage of the cancer meant the variety of patients in our study was wide-ranging. Therefore, future studies should investigate the level of effectiveness of medicinal cannabis in specific subgroups of cancer patients with more shared characteristics."