Can Cannabis Help Treat Cancer? What Largest-Ever Study Reveals

A new study has uncovered significant evidence supporting the use of medical cannabis in cancer treatment. The study suggests medical cannabis may not only alleviate symptoms but also combat the disease itself.

Published recently in Frontiers in Oncology, the study tries to establish a scientific consensus on the role of cannabis in cancer care.

Ryan Castle, research director at the Whole Health Oncology Institute and the lead author of the study, explained that the objective of this analysis was to address the ongoing debate by gathering and evaluating a vast array of studies.

“Our goal was to determine the scientific consensus on the topic of medical cannabis, a field that has long been dominated by a war between cherry-picked studies,” Castle was quoted as saying by The Guardian.

The research, which was funded by Cancer Playbook, a collaborative effort with the Whole House Oncology Institute to collect and analyse patient-reported data, is based on a review of over 10,000 studies related to medical cannabis and cancer. This huge pool of research reportedly surpasses the scale of any previous study in the field.

Despite limitations imposed by the restricted legal status of cannabis, which has hampered direct clinical studies on humans, the researchers used a broad spectrum of observational and laboratory-based studies. These include animal trials and cell research exploring the effects of cannabis on tumour growth. 

Castle's team endeavoured to incorporate as many of these studies as possible to ensure a comprehensive review.

Castle said, “To move beyond bias–conscious or not–it was essential to use a large-scale, radically inclusive methodology based on mathematical reasoning.”

The analysis showed a clear pattern. It identified studies with positive, neutral and negative views on cannabis's impact on cancer symptoms, such as appetite loss, inflammation and even the process of tumour cell death, known as apoptosis.

The findings were striking, especially regarding cannabis's ability to address symptoms like nausea and appetite loss. The study's most remarkable discovery was cannabis's potential to directly target cancer cells, with evidence suggesting it may inhibit their spread and promote cell death.

Although cannabis' potential as a cancer treatment has been met with some scepticism, especially due to concerns over its links to substance use disorders, the research has received both support and criticism. 

Oncologist Donald Abrams, a professor emeritus at the University of California, San Francisco, questioned the validity of these findings. 

Abrams, who has had extensive experience treating cancer patients in San Francisco, noted the therapeutic value of cannabis in managing cancer symptoms, including pain, nausea, and anxiety. But he expressed doubt about cannabis's ability to cure cancer, stating, “If cannabis cures cancer, I have not been able to appreciate that,” he told Guardian

Castle, though, is optimistic, citing both the pre-clinical evidence and encouraging patient outcomes as reasons to believe in cannabis's cancer-fighting potential.

He hopes that this meta-analysis will prompt the US Drug Enforcement Administration (DEA) to reconsider the federal classification of cannabis, thereby removing the current research restrictions.