A 2018/2019 Summer Studentship research project
Vitamin C plays a fundamental role in many biochemical functions in all cells of the body. Preliminary data has suggested that cancer patients may consume suboptimal amounts of the vitamin and subsequently have suboptimal plasma levels. It is established that plasma levels above 50 µM are adequate and below are inadequate, with levels below 23 µM described as hypovitaminosis C, and those below 11 µM as scurvy. This feasibility study will determine the prevalence of inadequate plasma vitamin C levels in patients with newly diagnosed cancer. It lays the groundwork for a larger study, and may lead to clinical recommendations specifically for patients with cancer.
Student: Rebecca White
Supervisors: Professor Margreet Vissers, Associate Professor Gabi Dachs, Helen Morrin, Dr Andrew Das, Professor Bridget Robinson
We are looking for a bright, enthusiastic medical student (ideally with a science background) to join our multidisciplinary cancer and biochemistry research groups. We have close links with the clinic and the proposed study forms an important part of our ongoing research.
The role of vitamin C in cancer remains controversial, following initial conflicting results from clinical trials in the 1970s and 1980s. There are now a number of possible mechanisms by which vitamin C could play a role in cancer, and we have shown an association between low tumour vitamin C levels and a more aggressive tumour phenotype in a number of different cancer types. Tumour levels of vitamin C are largely determined by the levels of the vitamin in circulation. The data on vitamin C status of cancer patients is sparse. A previous Summer Studentship (Dachs, Munn et al., NZMJ 2014) has showed that 80% of cancer patients surveyed did not consume the recommended daily intake of vitamin C, but plasma levels were not measured. This small study also showed that vitamin C intake was similar to healthy controls.
The aim of this feasibility study is to measure plasma levels of vitamin C in patients who are admitted to Christchurch Hospital for cancer surgery.
Patients attending the pre-admission clinic at Christchurch Hospital prior to the planned surgical resection of their cancer will be approached by the student and invited to take part in the study. Consented patients will answer a simple health questionnaire to record information on diet, vitamin C supplements and exercise, and weight, height and cancer diagnosis and stage will be recorded from their medical record. They will provide a small blood sample (5ml). The blood sample will be processed rapidly for subsequent batched vitamin C analysis, which is measured using HPLC-EC (high performance liquid chromatography with electrochemical detection). The HPLC method of ascorbate measurement is well established in our group, is highly accurate and represents the international gold standard. The patients will be recruited alongside consenting for Tissue banking which is well established in the preadmission clinic. Tissue banking has a very high consent rate and accrues over 700 donors per year, so we anticipate recruiting up to 100 patients to this study, especially with the usual high pre-Christmas surgery rates. Prevalence of inadequate vitamin C in this patient cohort will be determined and analyzed with respect to patient demographics and clinicopathological information.
Student researcher’s component of the study
The student will explain the study to potential participants, consent the patients, administer a simple questionnaire, rapidly transfer the blood tubes to the laboratory and process the plasma for analysis. The student will, with laboratory support, analyze the plasma samples for vitamin C content using HPLC-EC. The student will help interpret the results, considering age, gender, diet, ascorbate supplements, body mass index, cancer type and stage.
This study is related to a second study (determining vitamin C in plasma samples from patients with cancer undergoing treatment), and it is envisaged that the two students will work closely together on all aspects of the two studies.