A recent study on Vitamin C has lead to a resurgence of attention to Vitamin C for cancer.
From the abstract of the study:
High-dose vitamin C impaired tumor growth in Apc/KrasG12D mutant mice. These results provide a mechanistic rationale for exploring the therapeutic use of vitamin C for CRCs with KRAS or BRAF mutations.
There are several things to keep in mind. This study was done on mice. Very high-doses of Vitamin C were used (intravenous administration would be required in humans to reach equivalent doses). Human clinical trials are expected to follow and will hopefully shed more light.
Mark Levine, a known Vitamin C researcher, was part of a study published in 2005 which notes:
Ascorbic acid (vitamin C, ascorbate) has a controversial history in cancer treatment (1). Observational reports described ascorbate, given in pharmacologic doses of 10 g daily, as effective in treating some cancers and in improving patient well-being (2-4). Subsequently, the same dose had no effect on patient well-being and survival in two double-blind placebo-controlled trials, and ascorbate was discarded as a treatment modality (5, 6). Recent clinical evidence, however, indicates that the role of ascorbate in cancer treatment should be examined anew (7).
In the larger picture any approach relying on as single agent is far from a holistic approach. There are natural sources of Vitamin C that have many cofactors present that should be looked at too. Regardless, we are happy to see this avenue explored.