Half of Brain Tumor Patients Had Used Cannabis, Many Without Being Told About It
Among 100 Dutch brain tumor patients, 51% had ever used cannabis and 14% currently used it, primarily for symptom relief, with most favoring CBD over THC.
Quick Facts
What This Study Found
Fifty-one percent of brain tumor patients had ever used cannabis and 14% were current users. Nineteen percent used cannabis for tumor-related reasons, including symptom relief (74%) and presumed antitumor effects (42%). Patients preferred CBD over THC. Self-reported improvements included sleep, anxiety, worrying, and depressive symptoms. Common adverse effects were drowsiness, dry mouth, and dizziness.
Key Numbers
100 patients surveyed. 51% ever used cannabis. 14% current users. 19% used for tumor-related reasons. 74% for symptom relief, 42% for presumed antitumor effects. CBD preferred over THC. Sleep, anxiety, and depression most commonly improved.
How They Did This
Cross-sectional survey of 100 adult primary brain tumor patients visiting the neuro-oncology outpatient clinic at Amsterdam UMC between August and October 2023.
Why This Research Matters
Brain tumor patients face significant symptom burdens and limited treatment options. Understanding their cannabis use patterns and motivations can inform clinical conversations and identify areas needing evidence.
The Bigger Picture
The high prevalence of cannabis use among brain tumor patients highlights a gap between patient behavior and clinical guidance. Many patients are using cannabis without their oncologist knowing, potentially creating safety issues.
What This Study Doesn't Tell Us
Small single-center sample in the Netherlands, where cannabis is relatively accessible. Self-reported effects without objective measurement. Cross-sectional design. Survey at a specialized center may not represent all brain tumor patients.
Questions This Raises
- ?Does cannabis actually relieve brain tumor symptoms, or is there a placebo effect?
- ?Could cannabis interact with brain tumor treatments?
- ?Should oncologists routinely ask about cannabis use?
Trust & Context
- Key Stat:
- 51% of brain tumor patients had used cannabis
- Evidence Grade:
- Preliminary: small single-center cross-sectional survey with self-reported outcomes
- Study Age:
- Published in 2025 using August-October 2023 survey data
- Original Title:
- Cannabis use among Dutch patients with a primary brain tumor.
- Published In:
- Neuro-oncology practice, 12(4), 714-722 (2025)
- Database ID:
- RTHC-06038
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Can cannabis help brain tumor patients?
Patients in this study reported improvements in sleep, anxiety, and depressive symptoms, but these are self-reported and uncontrolled. Some also used cannabis hoping it would affect the tumor itself (42%). Clinical evidence for antitumor effects remains limited.
Which type of cannabis did brain tumor patients prefer?
Patients favored CBD over THC. This preference may reflect a desire to avoid psychoactive effects while still seeking potential therapeutic benefits.
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Cite This Study
https://rethinkthc.com/research/RTHC-06038APA
Belgers, Vera; Rietveld, Niek A; de Witt Hamer, Philip C; Niers, Johanna M. (2025). Cannabis use among Dutch patients with a primary brain tumor.. Neuro-oncology practice, 12(4), 714-722. https://doi.org/10.1093/nop/npaf009
MLA
Belgers, Vera, et al. "Cannabis use among Dutch patients with a primary brain tumor.." Neuro-oncology practice, 2025. https://doi.org/10.1093/nop/npaf009
RethinkTHC
RethinkTHC Research Database. "Cannabis use among Dutch patients with a primary brain tumor..." RTHC-06038. Retrieved from https://rethinkthc.com/research/belgers-2025-cannabis-use-among-dutch
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.