Vitamin C has demonstrated few pharmacologic properties, however the public attributed to this compound a great diversity of properties capable of curing a wide variety of diseases.
Apart from this nutritional aspect, an extensive and often confusing literature exists about the use of vitamin C in cancer. A great number articles, many of them published on websites and others in recognized scientific journals, account of this controversy.
The following references may help clarify the topic in question:
1) Verrax J, Calderon PB. The controversial place of vitamin C in cancer treatment. Biochem Pharmacol. 2008 Dec 15;76(12):1644-52.
3) Stephenson CM, Levin RD, Spector T, Lis CG. Phase I clinical trial to evaluate the safety, tolerability, and pharmacokinetics of high-dose intravenous ascorbic acid in patients with advanced cancer. Cancer Chemother Pharmacol. 2013 Jul;72(1):139-46.
I think there is still no conclusive evidence to prove the clinical effectiveness of vitamin C in the treatment of cancer. The topic should be handled carefully to avoid creating false expectations in people with cancer.
Article The controversial place of vitamin C in cancer treatment
Two-time Nobel Prize winner Linus Pauling, along with Ewen Cameron, MD, of Scotland, did a scientific study proving that 10 grams of Vitamin C, given by I.V., could extend the life of advanced cancer patients six-fold.
I think that in addition to vitamin c one must also add essential amino acids. Probably a high quality protein being that the body would receive all the amino acids. Glutathione has been linked to health and should be studied.