Pharmacological Ascorbate as a Means of Sensitizing Cancer Cells to Radio-Chemotherapy While Protecting Normal Tissue.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing preclinical research and early-phase clinical trials
PubMed 30573181 · doi:10.1016/j.semradonc.2018.10.006
What was done
This narrative review summarizes preclinical and early-phase clinical trial literature evaluating pharmacological ascorbate (intravenous infusions of vitamin C achieving plasma concentrations of at least 20 mM) as an adjuvant to standard chemoradiation therapy. The review evaluates mechanisms of action, tumor radio-chemosensitization, normal tissue protection, and clinical safety profiles.
What was found
The abstract reports that pharmacological ascorbate exhibits selective toxicity to cancer cells mediated by hydrogen peroxide (H2O2) generation, acts as a sensitizer to chemoradiation in cancer cells, protects normal tissues exposed to chemoradiation, and demonstrates safety and tolerability in early-phase clinical trials. No quantitative metrics, patient counts, or effect sizes are reported in the abstract.
Why it matters
Chemoradiation efficacy is heavily constrained by collateral toxicity to healthy tissues. Pharmacological ascorbate represents a potential dual-action adjuvant strategy aimed at enhancing tumor killing while reducing adverse normal-tissue damage.
Limits
As a narrative review, the synthesis lacks systematic search criteria and meta-analytic pooling. The evidence relies heavily on preclinical tumor models and non-randomized early-phase trials; the abstract provides no quantitative clinical efficacy, survival endpoints, or sample size data.
Cited by
- supports Pharmacologic doses of intravenous vitamin C greater than 1 g generate hydrogen peroxide.