The Riordan Clinic recently published an extensive paper combining 246 different medical resources about the benefits, for cancer patients, of taking vitamin C intravenously . The paper shows that IV use of vitamin C may be helpful in suppressing common effects of cancer such as cachexia (wasting) and immune suppression.
Using vitamin C in cancer patients has always been a controversial topic, not because it causes harm, but because some studies have claimed extending the life of cancer patients, while others have not seen any effects at all. The problem with the studies showing no effects with vitamin C and cancer is that the vitamin C that was used was administered orally. The scientists at the Riordan Clinic published and patented that vitamin C administered orally can achieve a high enough concentration in the blood to selectively kill tumor cells.
The paper can be viewed here : http:/.translational-medicine.com/content/pdf/1479-5876-9-25.pdf