Colorectal cancer is the fourth most common incident cancer and the second most common cause of cancer deaths in the United States. Ecologic studies indicated that colorectal cancer is heavily environmental influenced and thus preventable. An inverse relationship between calcium and colorectal cancer incidence has been widely accepted. The autocrine or paracrine growth factors TGFalpha and TGFbeta1 likely contribute to or at least affect colon carcinogenesis. In this study, we constructed a randomized, placebo-controlled, double-blinded clinical trial to investigate the effects of supplemental 1,200 mg elemental calcium and/or 1000 IU vitamin D daily over one year on the autocrine/paracrine growth factors TGFalpha and TGFbeta1 in the normal appearing rectal mucosa of sporadic colorectal adenoma patients. We hypothesize that the supplemental calcium and vitamin D may individually or jointly decrease the expression of TGFalpha and the ratio of TGFalpha to TGFbeta1 in the human colorectal mucosa. Slight differences were observed in several groups of discussion in both biomarkers' expression, while none of the treatment effect was statistically significant. The study result thus suggests that daily supplements of 1,200 mg elemental calcium and/or 1000 IU vitamin D may not have effect on the growth factors TGFalpha and TGFbeta1 in the normal appearing rectal mucosa of sporadic colorectal adenoma patients. Further investigations in larger clinical trial are needed to testify this conclusion.
Table of Contents
Part I: Introduction;
Part II: Thesis Manuscipt, with Background, Methods, Results and Discussion Part;
Part III: Summary, Public Health Implications and Possible Future Directions.
About this Master's Thesis
|Committee Chair / Thesis Advisor|