Cancer c
Pro Research Analysisby 
Searched over 200M research papers for "cancer c"
Consensus Meter
The Role of Vitamin C in Cancer Treatment
Vitamin C and Cancer Immunity
Vitamin C, also known as ascorbic acid, has been studied for its potential role in enhancing the immune system of cancer patients. Many cancer patients undergoing intensive chemotherapy often have low levels of vitamin C. Supplementation of vitamin C has been proposed to stimulate the production and activation of immune cells, potentially improving immunity in these patients. However, a systematic review of 19 trials found no conclusive evidence that vitamin C supplementation significantly improves overall survival, clinical status, quality of life, or performance status in cancer patients. The studies reviewed were of low quality, and the patient groups were diverse, suggesting that while vitamin C treatment is safe, its effectiveness may vary among different patient groups and administration methods, with intravenous administration showing more promise than oral supplementation.
Genetic Prediction of Vitamin C Levels and Cancer Prognosis
Recent research has explored the genetic prediction of vitamin C levels and their impact on cancer prognosis. A comprehensive pan-cancer analysis involving 5769 patients across 20 cancer types revealed that genetically predicted vitamin C levels, measured through a Vitamin C Index (VCI), were significantly correlated with overall survival and immune characteristics in multiple cancers. Specifically, higher VCI was associated with better prognosis in breast cancer, head and neck squamous cell carcinoma, kidney clear cell carcinoma, and rectum adenocarcinoma. Additionally, vitamin C was found to influence tumor mutational burden and microsatellite instability, particularly in colon and rectal adenocarcinoma, suggesting a potential therapeutic role in these cancers.
Circulating Vitamin C Concentrations and Cancer Risk
The causal relationship between circulating vitamin C concentrations and cancer risk has been investigated using Mendelian randomization. This study found no strong evidence of a causal association between circulating vitamin C levels and the risk of the five most common cancers in Europe, including lung, breast, prostate, colon, and rectal cancer. Although higher dietary vitamin C intake was associated with a lower risk of lung cancer, this was not observed with vitamin C supplementation. These findings suggest that while vitamin C intake may have some protective effects, physiological levels of circulating vitamin C do not have a large impact on cancer risk.
High-Dose Vitamin C and Cancer Cell Vulnerabilities
High-dose vitamin C has been proposed as a treatment for cancer due to its ability to target specific vulnerabilities in cancer cells. Preclinical studies have shown that pharmacological concentrations of vitamin C can selectively kill cancer cells by inducing redox imbalance, epigenetic reprogramming, and disrupting oxygen-sensing regulation. These mechanisms highlight the potential of high-dose vitamin C to be used in combination with other therapies to enhance its anticancer effects. However, clinical trials are needed to validate these findings and identify patient populations that may benefit the most from high-dose vitamin C therapy .
Clinical Trials and High-Dose Vitamin C
Clinical trials investigating the efficacy of high-dose vitamin C in cancer treatment have yielded mixed results. A randomized double-blind study involving patients with advanced colorectal cancer found no significant advantage of high-dose vitamin C over placebo in terms of disease progression or patient survival. This suggests that high-dose vitamin C may not be effective against advanced malignant diseases, regardless of prior chemotherapy status. However, other studies have reported that high doses of vitamin C can inhibit the proliferation of certain cancer cells, such as acute myeloid leukemia, by modulating intracellular compounds like glutathione and cysteine.
Conclusion
The role of vitamin C in cancer treatment remains a topic of ongoing research and debate. While vitamin C supplementation is safe and may have some benefits in specific patient groups, there is no conclusive evidence that it significantly improves overall survival or clinical outcomes in cancer patients. High-dose vitamin C shows promise in preclinical studies, but further well-controlled clinical trials are needed to determine its efficacy and identify the patient populations that may benefit the most.
Sources and full results
Most relevant research papers on this topic