Background: Concern has been raised that a low total serum cholesterol level, although beneficial for cardiovascular diseases, may increase the risk of cancer. This prospective cohort study analyses the hypotheses that a low total serum cholesterol level or its subfractions (serum low-density-lipoprotein cholesterol, high-density-lipoprotein cholesterol, and triglycerides) increase the risk of cancer of the colon and rectum.
Methods: Between 1977 and 1983, 62,173 men and women attended a health screening carried out by the Norwegian National Health Screening Service. The screening consisted of a questionnaire, anthropometric measurements, and samples of non-fasting blood drawn for analyses of serum total cholesterol, low-density-lipoprotein cholesterol, high-density-lipoprotein cholesterol, and triglycerides.
Results: During the 7- to 13-year follow-up, 186 patients were found to have colon cancer and 106 rectal cancer by linkage to the Norwegian Cancer Registry. Among men there were no associations between blood lipid and lipoprotein levels and risk of cancer of the proximal colon, distal colon, or the rectum. Among women there was a formal statistically significant inverse relationship between level of total cholesterol and low-density-lipoprotein cholesterol and risk of distal colon cancer, and a positive trend between total cholesterol level and rectal cancer.
Conclusions: The statistically significant results among women were interpreted as incidental, and we conclude that blood lipid and lipoprotein levels were not associated with the risk of colon or rectum cancer in men or women in this cohort.