The role of vitamin E in the etiology and prevention of colon cancer is not clear. It is possible that various forms of vitamin E may act differently in colon tissue and may be effective chemopreventive agents. Previous reports of vitamin E and colon cancer have focused on α-tocopherol and have not considered other dietary forms of vitamin E. Data from a study of 1,993 cases and 2,410 controls were used to evaluate the associations between the four most common forms of dietary vitamin E and supplemental vitamin E and colon cancer. After adjusting for other health and life-style factors, we did not observe a statistically significant association between dietary tocopherols and colon cancer. There were, however, suggestions of an inverse association between total α-tocopherol equivalents and colon cancer among women diagnosed with colon cancer before the median age of the control population, 67 years [odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.36-1.22] and a direct association between γ-tocopherol and colon cancer among these women (OR = 1.44, 95% CI = 0.92-1.93). Women diagnosed with colon cancer when ≤67 years of age appeared to have some protection from use of vitamin E supplements (OR = 0.80, 95% CI = 0.56-1.15). These data offer only limited support for a protective effect of vitamin E and colon cancer after adjustment for other health and life-style factors.
Bibliographical noteFunding Information:
The authors acknowledge the contributions and support of Drs. Richard Kerber and John Potter. This study was funded by National Cancer Institute Grant RO1 CA-48998 to M. L. Slattery and by the Utah Cancer Registry, the Northern California Cancer Registry, the Sacramento Tumor Registry, and the Minnesota Cancer Surveillance System. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official view of the National Cancer Institute. Address reprint requests to Dr. Martha L. Slattery. E-mail: email@example.com.