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.
Oncologists, patients with advanced liver cancer exploring complementary options, and researchers studying cannabinoid anti-tumor potential.
What the researchers 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.
Why it 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 numbers in context
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 the study worked
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.
What this study cannot 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.
How to read the evidence
Case reports of two patients with no control group. While the outcomes are remarkable, this is the lowest tier of clinical evidence.
When this study was published
Published 2025.
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.
Questions still open
- 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?
Common questions
Should cancer patients start taking cannabis oil based on this?
How rare is spontaneous regression of liver cancer?
Read the original research
Durable complete response of advanced hepatocellular carcinoma using cannabis oil: a report of two cases.
Journal of cannabis research, 7(1), 96
Citation
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
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