Two Patients With Advanced Liver Cancer Achieved Complete Tumor Regression Using Cannabis Oil
Two elderly patients with advanced hepatocellular carcinoma who took cannabis oil for symptom relief experienced durable and complete tumor regression, though these are only case reports and cannot prove causation.
Quick Facts
What This Study Found
Both patients (ages 82 and 77) with advanced hepatocellular carcinoma and high tumor burden achieved complete and durable tumor regression after using sublingual cannabis oil containing THC and CBD, with no other anti-cancer treatment.
Key Numbers
Patient A (age 82): 10% THC and 5% CBD oil, two droplets sublingually three times daily. Patient B (age 77): 15% THC and 2% CBD oil, five droplets sublingually twice daily. Both achieved complete response.
How They Did This
Case report of two patients with advanced HCC who were not candidates for standard treatment and received only cannabis oil (Patient A: 10% THC/5% CBD; Patient B: 15% THC/2% CBD) administered sublingually multiple times daily.
Why This Research Matters
Complete tumor regression in advanced liver cancer is extremely rare without treatment. While two cases cannot prove cannabis caused the regression, they add to preclinical evidence suggesting cannabinoids may have anti-tumor properties worth investigating in clinical trials.
The Bigger Picture
Hepatocellular carcinoma has limited treatment options for advanced cases. These cases join a small but growing body of anecdotal evidence suggesting cannabinoids may have anti-tumor effects, but clinical trials are urgently needed to determine whether these observations are more than coincidence.
What This Study Doesn't Tell Us
Only two patients — case reports are the weakest form of clinical evidence. Spontaneous regression of HCC, while rare, has been documented. No control group, no blinding, and many potential confounding factors.
Questions This Raises
- ?Could cannabinoids have genuine anti-tumor effects in liver cancer specifically?
- ?What mechanisms might explain complete regression?
- ?Would randomized trials of cannabis oil as adjunct therapy be feasible in advanced HCC patients?
Trust & Context
- Key Stat:
- Evidence Grade:
- Case reports of two patients with no control group. While the outcomes are remarkable, this is the lowest tier of clinical evidence.
- Study Age:
- Published 2025.
- Original Title:
- Durable complete response of advanced hepatocellular carcinoma using cannabis oil: a report of two cases.
- Published In:
- Journal of cannabis research, 7(1), 96 (2025)
- Authors:
- van den Berg, Pieter F, van der Heide, Frans, Ruiter, Simeon J S, Slangen, Jules J G, de Groot, Derk Jan A, van den Broek, Evert, Hoogwater, Frederik J H, Nijkamp, Maarten W
- Database ID:
- RTHC-07849
Evidence Hierarchy
Frequently Asked Questions
Should cancer patients start taking cannabis oil based on this?
No. Two case reports cannot prove cannabis caused the regression. Patients should discuss any complementary therapies with their oncology team and not substitute cannabis for proven treatments.
How rare is spontaneous regression of liver cancer?
Spontaneous regression of hepatocellular carcinoma is documented but extremely rare. The fact that both patients regressed is notable, but without controlled studies, the role of cannabis oil remains uncertain.
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Cite This Study
https://rethinkthc.com/research/RTHC-07849APA
van den Berg, Pieter F; van der Heide, Frans; Ruiter, Simeon J S; Slangen, Jules J G; de Groot, Derk Jan A; van den Broek, Evert; Hoogwater, Frederik J H; Nijkamp, Maarten W. (2025). Durable complete response of advanced hepatocellular carcinoma using cannabis oil: a report of two cases.. Journal of cannabis research, 7(1), 96. https://doi.org/10.1186/s42238-025-00353-0
MLA
van den Berg, Pieter F, et al. "Durable complete response of advanced hepatocellular carcinoma using cannabis oil: a report of two cases.." Journal of cannabis research, 2025. https://doi.org/10.1186/s42238-025-00353-0
RethinkTHC
RethinkTHC Research Database. "Durable complete response of advanced hepatocellular carcino..." RTHC-07849. Retrieved from https://rethinkthc.com/research/van-2025-durable-complete-response-of
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.