Mistletoe in Cancer Cell Biology: Recent Advances

Mistletoe (Viscum album L.) has been used in complementary cancer therapy for decades, but its mechanisms remained poorly understood until recently. This review synthesizes transformative advances in mistletoe cancer research from 2020 to 2025, focusing on newly discovered molecular mechanisms, immunomodulatory properties, and clinical applications. We conducted a comprehensive analysis of controlled studies, mechanistic investigations, and real-world evidence published between 2020 and 2025. The discovery of mistletoe-induced immunogenic cell death (ICD) represents a paradigm shift in understanding its anticancer effects. Mistletoe extracts trigger endoplasmic reticulum stress, leading to calreticulin exposure in 18-51% of cancer cells and a 7-fold increase in adenosine triphosphate (ATP) release. Three-dimensional culture models revealed enhanced macrophage reprogramming effects, with a 15.8% increase in pro-inflammatory interleukin (IL)-6 and a 26.4% reduction in immunosuppressive IL-10. Real-world evidence from over 400 non-small-cell lung cancer patients shows that combining mistletoe with programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors doubles median overall survival (6.8 to 13.8 months), with biomarker-selected populations experiencing up to a 91.2% reduction in death risk. The Johns Hopkins Phase I trial established intravenous administration safety at 600 mg three times weekly. Advanced analytical approaches including metabolomics, chronobiology, and machine learning are enabling precision medicine applications. These findings position mistletoe as a scientifically validated component of integrative oncology, bridging traditional medicine with evidence-based cancer care. Future research should focus on ferroptosis mechanisms, single-cell immune profiling, and standardized clinical protocols.