A new study renews the controversial idea that vitamin C might help fight tumor cells.
Tests in the lab, in mice and finally in real patients suggest a special intravenous formulation of the vitamin may enhance chemotherapy, and may reduce side effects at the same time.
The research, published in the journal Science Translational Medicine, is sure to be controversial. Doctors and practitioners of complementary medicine have tried using vitamin C, also known as ascorbate, for years. But it’s had mixed results in trials.
Qi Chen of the University of Kansas and colleagues took a look first at how ascorbate might work. Tests on ovarian tumor cells in lab dishes showed it busted up DNA in cancer cells but not in other cell types. Adding chemotherapy accelerated the effect. Mouse tests showed the combination didn’t seem to be toxic, so they took the trial to 25 women with advanced ovarian cancer -- one of the deadliest cancers.
“High-dose intravenous ascorbate was added to conventional paclitaxel/carboplatin therapy, and toxicity was assessed,” they wrote in their report.
Not only did the treatment appear to do no harm, but it also seemed to kill the tumor cells better and reduce side effects from the chemotherapy. There were not enough women taking part in the trial to really tell, but the researchers said it’s worth trying out the approach in more patients.
Melanie McConnell of Victoria University of Wellington in New Zealand agreed. “As a single agent, high-dose ascorbate does not demonstrate anticancer activity in clinical trials,” she wrote in a commentary. “However, ascorbate could be a useful addition to existing therapy as a combination agent because of its low toxicity profile.”
Doctors have become a little wary of using vitamins to treat or prevent cancer. They don’t always help, and some recent studies have suggested that some vitamins might actually fuel tumors. But there’s a difference between using an agent to prevent cancer, and using it to treat a tumor that has already developed.
“We believe that the time has arrived for research agencies to vigorously support thoughtful and meticulous clinical trials with intravenous vitamin C,” Chen said in a statement.