An apple a day may not keep the doctor away, but University of Iowa researchers are testing how massive doses of vitamin C could help fight three of the deadliest forms of cancer.
Doctor Joe Cullen, a U-I professor of surgery, is helping head up the study. He says they’re launching a new round of clinical trials in cancer patients using IVs of vitamin C along with chemotherapy and radiation. “Vitamin C acts as an antioxidant but we give very large doses and we give it intravenously and at those large doses, you get very, very high levels,” Dr. Cullen says. “So, we’ve increased the levels a hundred-fold and when you do that, it actually kills cancer cells.”
If you take vitamin C tablets that you buy at the drug store by mouth, Cullen says they have a limited usefulness. “If you take too much vitamin C orally, you don’t absorb as much and your kidneys just excrete it,” Cullen says. “We bypass all of those mechanisms when we give it intravenously. We give it at such a high dose that the kidneys can’t remove it that quickly and you get very high doses.”
The U-I has already been conducting trials using vitamin C to treat pancreatic cancer, non-small cell lung cancer, and an aggressive type of brain cancer known as GBM. So far, Cullen says the results are very encouraging, especially with a trial that just finished for locally-advanced pancreatic cancer. “We increased the overall survival from 11 months to 21 months,” Cullen says. “We have two long-term survivals that are almost out four years, which is kind of unheard of for pancreatic cancer. In one of our earlier trials, looking at patients with Stage 4 pancreatic cancer where the survival is about six months, we increased the survival to about 16 months.”
Researchers at U-I’s Holden Comprehensive Cancer Center have just received a five-year, $9.7 million grant from the National Cancer Institute to continue the trials of high-dose vitamin C. Cullen says it promises to be a safe, simple, cost-effective approach to improving treatment for many kinds of cancer.