High-dose intravenous vitamin C (IVC) therapy has been safely employed for at least 30 years as one form of complementary alternative medical treatments for cancer. We prospectively examined the effects of IVC on the quality of life (QOL) in cancer patients in a multicenter observational study.
This study involved 60 patients with newly diagnosed cancer who visited participating institutions in Japan between June and December 2010 for IVC as an adjuvant cancer therapy. Using the QOL questionnaire developed by the European Organization of Research and Treatment of Cancer (EORTC), EORTC-QLQ C30, QOL was assessed before, and at 2 and 4 weeks of IVC therapy.
The global health/QOL score significantly improved from 44.6 ± 27.8 to 53.2 ± 26.5 (p < 0.05) at 2 weeks and to 61.4 ± 24.3 (p < 0.01) at 4 weeks. Patients also showed significant increases in physical, role, emotional, cognitive, and social functioning at 4 weeks after IVC (p < 0.05). In the symptom scale, significant relief was observed, especially in the score of fatigue, pain, insomnia, constipation, and financial difficulties.
According to the Clinical Global Impression of Change (CGIC), attending physicians evaluated the QOL of their patients as minimally to much improved in 46.7% (28/60) and 60.0% (30/60) at 2 and 4 weeks after IVC, respectively. Only 2 patients at 2 weeks and 3 patients at 4 weeks were evaluated as minimally worse. Moreover, all adverse events were mild, and none of the patients discontinued the therapy because of adverse reactions to IVC.
IVC can safely improve the QOL of cancer patients. These results warrant the conduct of prospective comparative studies to evaluate the usefulness of IVC for patients with advanced cancer.