Vitamin C For Some Types Of Colon Cancer– It’s Not An Option, But There Is A Legitimate Clinical Trial In Progress

Other doctors may be slightly less enthusiastic, but ultimately agree that the study is promising. “It’s probably an overzealous characterization but I don’t think it’s necessarily wrong,” says Dr. Heather Yeo, Colorectal Surgeon and Surgical Oncologist at Weill Cornell Medicine and NewYork-Presbyterian. “It’s in human trials, but they are still accruing and haven’t published anything yet.”

The clinical trial uses intravenous (in the veins) infusions of vitamin C in patients with respectable or metastic solid tumor malignancies, who have a mutation on the BRAF or KRAS genes. The KRAS gene marks a departure from other trials. “What differentiates this trial specifically is that it targets the KRAS protein,” according to the study’s principal investigator Dr. Manish Shah. “So about 40% of colon cancers have a mutation on KRAS and that’s been very challenging to target. We’re in an era of targeted therapy where we want to identify molecular mutations and then leverage those to find better treatments.”

Dr. Yeo agrees that the primary discovery was that the BRAF and KRAS mutations were important to the utility of the vitamin. “Their initial results were disappointing, because they were looking at all colon cancer patients and it is not helpful for all colon cancer patients,” she says.

The tumors involved use glucose as fuel for growth. “[The trial] basically demonstrates that patients with tumors who has KRAS or BRAF mutation, these tumors are hungry and dependent on glucose. So the tumors over-express a protein that allows glucose to enter,” says Dr. Shah.

And the receptors it produces to pick up glucose, also pick up vitamin C, and that’s important for destroying the cancer. “Turns out that vitamin C, when it gets oxidized outside the cell, enters through the same exact receptor and that actually leads to the buildup of pre-radical oxygen species, and that actually leads to killing the cell,” says Dr. Shah.

Dr. Shah calls the trial a “translational work,” which means taking concepts from biology and clinical trials and applying them to improve health outcomes. “This trial is sort of a complete translational work to verify that in KRAS of BRAF mutant tumors, Vitamin C may have some activity.” says Dr. Shah. “Vitamin C is given three to four times a week over a two to three hour infusion.”

At this point, the trial is going well. “You know, patients actually seem to be doing quite well with it because it’s a vitamin after all,” says Dr. Shah.

Not all cancer patients with the KRAS or BRAF mutation are eligible for the trial. “The eligibility criteria included patients who have a KRAS or BRAF mutation, and who have progressed on at least one line of standard therapy,” says Dr. Shah. “And also we have another cohort where patients might get vitamin C for a brief period of time, two to four weeks, before surgery. So if you have a GI cancer, preferentially colon cancer, pancreatic cancer, or even a lung cancer, you might be eligible for the pre operative vitamin C portion. But the other portion is for metastatic patients who have progressed on first line therapy.”

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