Benefits of high-dose vitamin C for ovarian cancer patients
Benefits of high-dose vitamin C for ovarian cancer patients
Based on information released by the University of Kansas Cancer Center, it has been found that Vitamin C when given in huge dosages by injection helps chemotherapy fight ovarian cancer in women suffering with this dangerous disease and what’s more it reduces the toxic effects on healthy cells, and reduces the ill effects of powerful cancer fighting drugs in these patients.
The scientists at the University of Kansas Medical Center determined that high doses of vitamin C, administered intravenously with traditional chemotherapy, helped kill cancer cells while reducing the toxic effects of chemotherapy for some cancer patients. By evaluating the therapy in cells, and in animals, and in human patients, the researchers found that a combination of infused vitamin C and the conventional chemotherapy drugs carboplatin and paclitaxel stopped ovarian cancer in the laboratory and in patients, and reduced chemotherapy-associated toxicity in patients with ovarian cancer. The results of their study have been published in the journal Science Translational Medicine.
"In the 1970s, ascorbate, or vitamin C, was an unorthodox therapy for cancer. It was safe, and there were anecdotal reports of its clinical effectiveness when given intravenously. But after oral doses (taking it by mouth) proved ineffective in two cancer clinical trials, conventional oncologists abandoned the idea. Physicians practicing complementary and alternative medicine continued to use it, so we felt further study was in order," explains the study's senior author, Qi Chen, Ph.D., Assistant Professor in KU Medical Center's Department of Pharmacology, Toxicology and Therapeutics and the Department of Integrative Medicine. "What we've discovered is that, because of its pharmacokinetic differences, intravenous vitamin C, as opposed to oral vitamin C, kills some cancer cells without harming normal tissues."
The researchers' clinical trial involved 27 patients with newly diagnosed Stage 3 or Stage 4 ovarian cancer. All of the participants received conventional therapy with paclitaxel or carboplatin, while some were also treated with high-dose intravenous vitamin C. Researchers monitored the participants for five years. Those patients who received vitamin C tended to experience fewer toxic effects from the chemotherapy drugs.
In laboratory rodents, the scientists observed that vitamin C was able to kill cancer cells at the concentrations achievable only by intravenous infusion, with no observable toxicity or pathological changes in the liver, kidney or spleen.
The researchers also sought to understand the cellular mechanisms by which pharmacological doses of vitamin C manifests this therapeutic benefit in cancer. "We aimed to investigate the mechanisms of vitamin C-induced cell death in the laboratory. And in patients with ovarian cancer, we conducted an early phase clinical trial examining safety and toxicity of high dose intravenous vitamin C. We now have a better understanding of vitamin C's anti-cancer action, plus a clear safety profile, and biological and clinical plausibility with a firm foundation to proceed," Dr Drisko says. "Taken together, our data provide strong evidence to justify larger and robust clinical trials to definitively examine the benefit of adding vitamin C to conventional chemotherapy." The study results are published in Science Translational Medicine, 2014; 6 (222): 222ra18 DOI: 10.1126/scitranslmed.3007154
In a previously report high-dose intravenously administered vitamin C apparently led to longer-than-expected survival in three patients with advanced cancer, doctors at the National Institutes of Health in Bethesda, Maryland and colleagues in Canada reported. Two of the three patients are still alive without evidence of disease.
In the three cases described in the Canadian Medical Association Journal, vitamin C was given intravenously at doses ranging from 15 to 65 grams to produce plasma concentrations that cannot be achieved by taking vitamin C by mouth.
> The first patient was a 51 year-old-women with advanced renal cancer who underwent surgical removal of the kidney but had evidence that the cancer had spread to the lungs. She received IV vitamin C 65 grams twice a week for 10 months, in combination with other alternative therapies. Repeat chest x-ray revealed one small spot, assumed to be a scar. Five years later, new lung masses were detected. The patient again received intravenous vitamin C, with unsuccessful results.
> The second patient, a 49-year-old man, had bladder cancer with multiple satellite tumors. He received IV vitamin C 30 grams twice a week for three months, followed by 30 grams vitamin C once every 1-2 months for four years. Nine years after diagnosis, the patient is in good health, without signs of disease.
> Case three was a 66-year-old woman with lymphoma invading spinal muscle and bone. She received IV vitamin C 15 g twice weekly for 7 months, then 15 g every 2-3 months for about one year. Ten years after diagnosis, the patient is in good health.
Dr. Mark Levine of the National Institutes of Health and colleagues note that all three patients survived for longer than expected for the types and stages of cancers that they had. At the doses delivered, vitamin C “is a pro-drug for hydrogen peroxide formation,” they explain. Histology results also showed evidence of tumor hemorrhage, attributable to vitamin C. Based on their three patients, “the role of high-dose intravenous vitamin C therapy in cancer treatment should be reassessed,” the authors conclude.
SOURCE: Canadian Medical Association Journal, March 28, 2006.
Commentary by Jerry Hickey, R PH;
Scientists feel that vitamin C gets into the nooks and crannies between the cancer cells releasing hydrogen peroxide and this is weakening the cancers making them potentially more treatable. Interestingly Vitamin C has just the opposite effect in healthy cells.