Chemotherapy patients experiencing neuropathic pain may find relief from cannabis, according to a new study published last month.

The study, which was published in last month’s issue of the journal Therapeutic Advances in Medical Oncology, comes via a team of Tel Aviv-based researchers who examined a cohort of 513 patients who were taking oxaliplatin for gastrointestinal issues. Oxaliplatin, the researchers said, “is a platinum-based chemotherapy widely used for the treatment of gastrointestinal (GI) malignancies.” According to the Mayo Clinic, it is used “along with other medicines (eg, fluorouracil, leucovorin) to treat advanced cancer of the colon or rectum,” while also being “used to treat severe colon cancer in patients who have had a surgery.”

The Israeli research team said that chemotherapy-induced peripheral neuropathy is “a well-known toxicity associated with the treatment of oxaliplatin,” which “has a strong impact on the quality of life of cancer patients.”

“Acute oxaliplatin-induced neuropathy is evident in up to 90% of oxaliplatin-treated patients, and continued exposure may lead to severe chronic neuropathy in approximately 31%,” they said.

The Method and Results of the Study

For the study, the researchers treated 248 of the patients in the cohort with cannabis, with the remaining 265 serving as the control group. The cohort was made up of 250 females and 263 males, according to the researchers, and all were diagnosed with gastrointestinal malignancies. 

“The rate of neuropathy was reduced among patients treated with cannabis and oxaliplatin,” the researchers wrote in their conclusion. “This reduction was more significant in patients who received cannabis prior to treatment with oxaliplatin, suggesting a protective effect. A large prospective trial is planned.”

“Oxaliplatin-induced neurotoxicity is a profound adverse effect which, according to the results of our investigation, may be mitigated and prevented by cannabis treatment,” they added.

The researchers highlighted the strength of the study, saying it was owed to the “reliability of the data on cannabis use, since all of the participating patients received cannabis by regulated licensure.”

“It was possible to follow the dates, dosages, and indications of cannabis treatment by reviewing the patients’ cannabis approval documentation,” they said. “Additionally, the data were retrieved from a large and high-quality tertiary care center database that includes medical records of patients with various GI malignancies and several treating physicians over a period of more than 2 years.”

They continued: “The main limitation of this trial is that the comparison of cannabis use was not quantitative but qualitative: it was not possible to compare the amount of licensed cannabis or the types and indications for its use since these parameters were not specified. Also, neuropathy assessment was retrospective and relied on the doctors’ records of patients’ complaints and physical examinations.”

The effectiveness of cannabis treatment on cancer patients has long been understood, but its ubiquity has increased considerably with the adoption of new marijuana laws both in the United States and elsewhere. A study late last year found that one-third of cancer patients in Canada, where medical marijuana has been legal since 2001 and where recreational pot use was legalized in 2018, use marijuana.