Many cancer patients seek alternative therapies for their disease, with the administration of high-dose vitamin C being commonplace. This practice continues despite a lack of evidence as to its efficacy and a lack of understanding of how vitamin C might be of benefit. Our project aims to address this gap in our knowledge. Our investigation is based on previous laboratory studies, animal trials and the analysis of human cancer tissue samples, all of which indicate that the more ascorbate there is in a tumour, the slower it will grow. In this proposal we will test the feasibility of collecting tumour tissue from a group of patients with colorectal cancer before and after surgery, whether the vitamin C accumulates in the tumour tissue, and whether this affects the biology of the tumour in a way that could slow growth the cancer growth and spread.