Cannabis shows no liver damage risk in advanced cancer patients

This substudy examined whether medicinal cannabis causes liver damage in patients with advanced cancer by measuring liver enzyme levels (ALT and AST) in 287 participants across two randomized clinical trials. Patients received escalating doses of CBD alone, THC/CBD combinations, or placebo, with measurements taken at baseline, day 14, and day 28. The key finding: medicinal cannabis did not cause elevation in liver enzymes at doses studied (up to 600 mg CBD/day), providing reassuring safety data for cancer patients considering cannabis treatment.

The study found no clinically meaningful differences between CBD-only and THC/CBD combination products in their effects on liver enzymes. Most importantly, no patients in either cannabis group exceeded dangerous enzyme thresholds (3× upper limit of normal, or 5× for those with liver metastases). This is significant because cancer patients often have compromised liver function, making them a vulnerable population. The first 4 weeks of treatment showed no significant adverse hepatic effects, which is crucial baseline data for long-term safety assessment.

These findings have practical implications for cancer patients exploring medicinal cannabis as a complementary treatment option. While this substudy focused specifically on short-term liver safety over 4 weeks, it provides important evidence that medicinal cannabis products don't cause acute liver enzyme elevation at clinically-used doses—a concern that had not been thoroughly evaluated in this vulnerable patient population previously. However, patients should continue regular liver function monitoring as part of their overall cancer care.