A new systematic review and meta-analysis published in Pharmaceuticals (May 2026) demonstrates that cannabinoids — including CBD, THC, and synthetic variants — may possess anti-tumor properties and enhance the effects of chemotherapy, particularly in glioblastoma and breast cancer. The study encompasses 189 preclinical trials.
Comprehensive Mapping of Cannabinoid Effects on Tumors
Cannabinoids such as CBD and THC have long been studied for their potential anti-tumor properties, but results have varied. Researchers across several European universities have now conducted the most comprehensive meta-analysis at the preclinical level to date, covering 189 studies from PubMed, Embase, and CENTRAL.
Get the week’s important news from Cannabis.se in your inbox — interesting weekend reading! 🥦✉️
CBD, THC, and Synthetic Cannabinoids Tested
The study includes both in vitro experiments and animal models, where cannabinoids were tested both as standalone treatments and in combination with chemotherapy agents.
Greatest Effects in Glioblastoma and Breast Cancer
Glioblastoma (brain tumor): Cannabinoids reduced tumor volume by 981 mm³. Combination with temozolomide showed additional effect.
Breast cancer: CBD + doxorubicin produced the strongest effect in the entire study — a 1,295 mm³ reduction compared to chemotherapy alone.
Lung cancer: Significant reduction of 562 mm³
Prostate cancer: Significant reduction of 1,137 mm³
Inconclusive Results for Other Cancer Types
For colorectal, pancreatic, and liver cancer, results were inconsistent or absent.
Results Should Be Interpreted with Caution
The researchers emphasize that the high heterogeneity between studies means the findings are hypothesis-generating. Human clinical trials are needed.
Sponsor: Sensi Seeds are one of Europe’s most recognized names in premium cannabis genetics, offering a wide selection of feminized, autoflowering, CBD-rich and F1 hybrid seeds for customers who want quality, consistency and choice.