The State of Evidence on Medical Marijuana in Cancer Care | Research

The takeaway

A review found that while medical marijuana shows promise for cancer-related symptoms and preclinical anticancer effects, evidence-based dosing information is lacking and the gap between patient interest and scientific evidence remains wide.

Cancer patients considering medical marijuana and clinicians looking for an evidence summary.

Evidence-based dosing information for cannabis in cancer care was described as lacking

What the researchers found

This review addressed the state of evidence for medical marijuana in cancer care, identifying both the potential and the significant knowledge gaps.

On the benefit side, cannabis may help with cancer-related symptoms including nausea, pain, appetite loss, and possibly neuropathy. Preclinical data suggest potential anticancer effects, but no clinical trials had confirmed these in humans.

On the practical side, the review noted a disconnect: medical marijuana was legal in 24 states plus DC but remained federally illegal, creating challenges for research, prescribing, and quality control. Evidence-based dosing and administration guidance were described as lacking, and the quality of available cannabis products was inconsistent.

Why it matters

Cancer patients are among the most common medical cannabis users, yet many oncologists feel unprepared to discuss cannabis due to limited evidence. This review highlighted the need for clinical trials and standardized dosing to bridge the gap between patient demand and evidence-based medicine.

The numbers in context

Medical marijuana legal in 24 states plus DC at time of publication. Federal Schedule I classification persisted. Evidence-based dosing information was described as lacking.

How the study worked

This was a clinical review published in Current Oncology Reports, examining published research on cannabis in cancer care, including symptom management studies, preclinical anticancer research, legal considerations, and ongoing clinical trials.

What this study cannot tell us

This was a narrative review that acknowledged the insufficient evidence on many topics it covered. The legal landscape described has since changed. The review could not provide definitive guidance on efficacy due to the limited trial data available.

How to read the evidence

This is a clinical review acknowledging that much of the evidence base is insufficient for definitive clinical guidance.

When this study was published

Published in 2016. The legal landscape has changed substantially, and some additional clinical trial data have emerged since then.

The bigger picture

The tension between patient interest in cannabis for cancer care and the limited clinical trial evidence continues to be a challenge for oncology. Since this review, some additional clinical trials have been conducted, but the evidence base for many claimed benefits remains thin.

Questions still open

Will clinical trials confirm the preclinical anticancer effects of cannabinoids? How should oncologists counsel patients about cannabis use in the absence of robust dosing guidelines?

Common questions

Should cancer patients use marijuana?

The review found potential benefits for symptom management but noted insufficient evidence for anticancer effects in humans and a lack of dosing guidance. Cancer patients should discuss cannabis with their oncology team to weigh potential benefits and risks in their specific situation.

Why is there so little research on cannabis and cancer?

The federal Schedule I classification created significant barriers to conducting clinical trials. Researchers face regulatory hurdles, limited funding, and difficulty obtaining standardized cannabis products for studies. Some of these barriers have eased but remain significant.

Read the original research

The Use of Medical Marijuana in Cancer.

Current oncology reports, 18(7), 40

View on PubMed ↗Publisher’s paper ↗

Citation

Birdsall, Shauna M; Birdsall, Timothy C; Tims, Lucas A. (2016). The Use of Medical Marijuana in Cancer.. Current oncology reports, 18(7), 40. https://doi.org/10.1007/s11912-016-0530-0