Meta-Analysis of Research on Cannabis and Cancer Aims to Find Consensus in Results

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A recently published meta data analysis aimed to find a consensus on medical cannabis for cancer palliative care and anticarcinogenic effects, noting the obstacles to research due to cannabis being a Schedule I substance (1). Researchers focused on published literature on the therapeutic potential of cannabis as well as safety profiles and role in cancer remission. The study, “Meta-analysis of medical cannabis outcomes and associations with cancer,” was published in Frontiers in Oncology in April 2025.

As noted in the study’s introduction, previous research on cannabis is inconsistent and constrained by lack of funding and access, legal challenges, and a reliance on self-reported data. Research on cannabis and cancer has also been complicated by the various types of both cannabinoids and of cancer types. For the current analysis, nearly 40,000 data points from more than 10,000 peer-reviewed research papers on cannabis and health outcomes was analyzed. Sentiment language was used to determine, based on predetermined correlating keywords, subjective information and the tone of each study: positive, negative, or neutral. The results were used to determine trends and insights at a large scale and synthesize results from various types of studies.

The results suggested a strong presence of positive associations with the therapeutic properties of cannabis. One highlighted result demonstrated significant findings after averaging sentiment correlations and keyword occurrence for all cancer-related topics (tumor size, pain, appetite, etc): “the correlation strength of cannabis and all cancer topics with supported sentiments was 31.38× stronger than that of not supported sentiments, and 36.79× stronger than with unclear sentiments. The correlation strength of cannabis and all cancer topics with not supported sentiments was 1.17× stronger than that of unclear sentiments.” The highlighted uses for cannabis include anti-inflammatory potential, appetite stimulation, and for pain and nausea management.

One limitation of the study was the potential for inaccuracies due to the use of machine learning to assess the sentiment and nuances of medical language in the studies. Additionally, the mechanisms for cannabis and inflammation and with opioid use in pain management was not clearly established. More clarification is also needed for the role of cannabis in cancer remission.

Ultimately, the consensus on research concerning cannabis and cancer was found to have significant implications, enough for reconsidering its scheduling status due to evidence for therapeutic use. “The consistency of positive sentiments across a wide range of studies suggests that cannabis should be re-evaluated within the medical community as a treatment option,” the researchers concluded. “The findings have implications for public health research, clinical practice, and discussions surrounding the legal status of medical cannabis. These results suggest a need for further research to explore the full therapeutic potential of cannabis and address knowledge gaps.”

Reference

1. Castle, RD.; Marzolf, J.; Morris, M.; Bushell, WC. Meta-analysis of medical cannabis outcomes and associations with cancer. Frontiers in Oncology. 2025. DOI: 10.3389/fonc.2025.1490621.