Study Results Show Promise and Indicate Further Investigation is Warranted
(May 20, 2013 – Schaumburg, IL) The use of vitamin C to treat cancer patients first became popular in the 1970s as a result of the work of Nobel Laureate Linus Pauling. However,
studies conducted with orally dosed supplements did not demonstrate any clinical benefit in cancer patients, most likely due to the finding that the levels of orally-administered vitamin C
delivered to a patient’s blood stream were considerably lower than the levels needed to kill cancer cells in either test tube or animal models. Recent studies in which vitamin C was
administered intravenously (by IV) resulted in higher levels delivered to the patient’s bloodstream suggest that vitamin C may, in fact, promote anti-cancer activity.
A research team at Cancer Treatment Centers of America (CTCA), led by Robert Levin, MD, and Christopher M. Stephenson, DO, recently completed a phase I clinical trial to determine the
pharmacokinetics, safety and tolerability of IV-administered, high dose vitamin C at levels that could potentially achieve the serum concentrations adequate for anti-cancer activity. The
results have been published in the May edition of Cancer Chemotherapy and Pharmacology.
As noted in the study, a previous hPase I IV vitamin C trial stopped dose escalation at approximately 56 g/m2, when peak blood levels approached 26 mM, a level that inhibited tumor
growth in mice . However, 30-40 mM ascorbic acid in mouse blood only partially inhibited the rate of tumor growth and did not result in tumor regression. Dr. Stephenson and his team
were seeking to obtain even higher blood concentrations. Their 70-80 g/m2 dose delivered blood concentrations of 49 mM. These levels appear to have a greater potential for producing
anti-cancer activity in future studies.
“While this may be the baseline for treatment potential,” said Dr. Stephenson, “it suggests we are on the right track for future studies and eventual use in fighting cancer.”
The use of IV-administered vitamin C in combination with cytotoxic chemotherapy is further encouraged by a recent report showing that vitamin C potentiated the antitumor activity of
gemcitabine against seven human and one murine pancreatic cancer cell lines . This observation is of particular interest as two of the human lines were resistant to gemcitabine.
Synergistic antitumor activity occurred in tissue culture and in vivo studies with implanted tumors in mice. In addition, a recently published phase I clinical trial evaluated IV-administered
vitamin C combined with gemcitabine and erlotinib in nine patients with stage IV metastatic pancreatic cancer. Pharmacologic levels of vitamin C were potentially achieved in all
participants and tumor volumes decreased in eight out of nine patients .
The findings of the CTCA study, coupled with the emerging evidence from the available literature, suggest that the combination of IV-administered vitamin C with gemcitabine to treat
pancreatic cancer is therapeutic approach that warrants further evaluation. The CTCA research team is planning to conduct a phase 2 study using the higher dose of 70-80 g/m2 to
achieve more adequate and longer lasting blood concentrations of vitamin C to better understand the possible outcome of this increased dosage.
About Cancer Treatment Centers of America®
Cancer Treatment Centers of America® (CTCA), headquartered in Boca Raton, Fla., is a national network of five hospitals that serves adult patients who are fighting cancer. CTCA® offers an integrative approach to care that combines advancements in genomic testing and precision cancer treatment, surgery, radiation, immunotherapy and chemotherapy, with evidence-based supportive therapies designed to help patients physically and emotionally by enhancing their quality of life while reducing side effects both during and after treatment. CTCA serves patients from around the world at its hospitals in Atlanta, Chicago, Philadelphia, Phoenix and Tulsa. Consistently rated among U.S. hospitals that deliver the highest quality of care and patient experience, CTCA provides patients and their families with comprehensive information about their treatment options and encourages their active participation in treatment decisions. For more information, visit cancercenter.com, Facebook.com/cancercenter and Twitter.com/cancercenter.