Scientific Clinical Studies are an important mathematical tool used by physicians.
The following links provide the findings about the efficency of intravenous vitamin C in the treatment of cancer.
https://www.ncbi.nlm.nih.gov/pubmed/24500406
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4199254/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2693571/
https://www.ncbi.nlm.nih.gov/pubmed/23670640
http://www.personalizedmedicineuniverse.com/article/S2186-4950(12)00013-2/fulltext