Abstract:
Colorectal cancers (CRC) are highly prevalent cancer all over the world and need appropriate and timely
prevention and treatment. Since years it has been argued that antioxidant vitamins have a potential role in the
prevention of several neoplasm including colorectal cancer though the answer remained controversial. Most of
the observational studies in past have shown that Vitamin E has some protective effect in the primary
prevention of colorectal cancer, however its exact role is not yet established. On the other hand recently
conducted experimental studies have shown variable results regarding the role of vitamin E in preventing
colorectal cancers. Thus this review was conducted to study the role of vitamin E in preventing colorectal
neoplasm. This review study was conducted from September 2008 to February 2009. We searched multiple
electronic sources including (PUBMED) MEDLINE, Cochrane Database for identifying existing Systematic
Reviews, OVID data base and other library sources to identify relevant studies for this review. Data was
collected using data extraction form. Meta analysis was performed in Review Manager version 4.3. We
identified four trials on vitamin E role for primary prevention of CRC, includes 94069 participants (47029 in
vitamin E Vs 47040 in placebo), aged 40 years or above, who were randomized to vitamin E supplement versus placebo. The outcome measure in our review was incidence of colorectal cancer in the follow up period of 7 to 10 years. We found no sufficient evidence of vitamin E role for decreasing risk of CRC incidence (RR: 0.89,CI: 0.76, 1.05; p-value = 0.18). It has been identified in the review that Vitamin E does not have protective role in the prevention of colorectal cancer. Further studies on diverse population are required to determine the role vitamin E for the primary prevention of colorectal cancer.
