The effect of vitamine d replication on prognosis in patients with colorectal cancer

ABSTRACT The Effect of Vitamine D Replication on Prognosis in Patients with Colorectal Cancer Baskent University Faculty of Medicine, Department of Internal Medicine Thesis, Ankara, 2018 Colorectal cancers are the most frequent type of cancers in the world. Colorectal cancers are the fourth most common cancer diagnosed in the U.S.A and second most common cancer causing death (1). It is known that vitamine D has an effect on the cancer pathophysilogy. It is especially effective in inhibiting cell proliferation and in increasing apoptosis (2). Some cohort studies have revealed that deficiency of vitamine D increases the incidence of colorectal cancer; and data also exist which support that vitamine D replacement therapy may reduce the risk of colorectal cancer (3-7). Data about the effect of replacement therapy on the prognosis and clinical course in patients having vitamine D deficiency who were diagnosed as colorectal cancer are not still clear. The purpose of this study is to retrospectively analyze the effect of vitamin D level at the time of diagnosis on the overall survival in patients with colorectal cancer and to evaluate differences in the survival of those having vitamin deficiency depending on the condition of receiving or not receiving vitamin D replacement. 100 patients applied to Oncology Department of Başkent University Hospital and diagnosed as colorectal cancer and checked for vitamine D level during diagnosis between january 1, 2006 and March 08, 2018 were included in this study. İn statistical analysis, Chi-square test, Kaplan-Meier, and Cox Regression Models were used. It was concluded from this study that the level of vitamine D during diagnosis might be a significant predictor for the prognosis of colorectal cancer. Replacement therapy in patients with deficient level of vitamine D during prognosis was detected as a negative factor in our study. Data related to this subject are still need to be further evaluated in large-scale prospective studies. Key Words: Colorectal Cancer, Vitamine D, prognosis, replacement