Serum cholesterol and subsequent risk of cancer: results from the BUPA study.

In the BUPA study, a prospective study of 22,000 men attending a screening centre in London, the mean serum cholesterol level of the 267 men who developed cancer was 6.66 mmol l-1, not significantly different from the mean level of 6.72 mmol l-1 among the 525 unaffected controls matched for age, smoking history and the calendar quarter of their attendance at the screening centre. There was, however, a significant difference in serum cholesterol levels among men who were diagnosed as having cancer less than 2 years after the date of blood collection (6.49 mmol l-1 for the 116 cancer subjects and 6.78 mmol l-1 for the 224 controls (P = 0.02)) but not in men who developed cancer 2-11 years after blood collection (6.79 mmol l-1 for the 151 cancer subjects and 6.68 mmol l-1 for the 301 controls). The observation that the association between low serum cholesterol and cancer was confined to men in whom a diagnosis of cancer was made within 2 years after the date of blood collection suggests that the low serum cholesterol is a metabolic consequence rather than a precursor of the cancer. Our results, which are consistent with the majority of other published studies, indicate that a low serum cholesterol is not a cause of cancer.