Cholesterol linked with prostate cancer outcome

NEW YORK (Reuters Health) - Men with low cholesterol have a reduced risk of developing more aggressive forms of the prostate cancer, but not a lower risk of developing prostate cancer overall, compared with men with higher cholesterol levels.

The findings, reported at a cancer prevention conference in Boston this week, may help explain the findings of an earlier study by some of the same researchers in which men who took cholesterol-lowering statin drugs had half the risk of advanced prostate cancer and one third the risk of fatal prostate cancer, compared with men who did not take these drugs.

Statin drugs reduce cholesterol in the blood, but they also influence a number of different pathways, possibly related to prostate carcinogenesis, study chief Elizabeth Platz from Johns Hopkins Bloomberg School of Public Health in Baltimore noted at the conference. Some scientists theorize that abundant cholesterol in the blood could help abnormal prostate cells survive longer.

Platz and associates analyzed stored blood drawn between 1993 and 1995 from 698 men before they were diagnosed with prostate cancer and the matched these samples to blood drawn during the same period from another 698 men who did not develop prostate cancer.

All of the men are part of the ongoing Health Professionals Follow-up Study, initiated in 1986 to look at lifestyle factors related to cancer and other chronic diseases.

According to Platz, average cholesterol levels did not differ between men with prostate cancer and those without, which suggests that cholesterol is not involved in the initiation of the disease.

However, on further analysis, they found that men with the lowest cholesterol levels, compared with those with the highest, had a 40-percent lower risk of high-grade prostate cancer -- a more worrisome form of the disease.

Similarly, men with the lowest cholesterol levels had a 50-percent lower risk of advanced prostate cancer. Low cholesterol was defined as 165 milligrams per deciliter of cholesterol.

"In a sub-analysis, we excluded men who were taking any type of cholesterol-lowering drug and our results persisted," Platz said.

"The results of the present study," the authors conclude, "coupled with our finding for statins, suggest a line of mechanistic studies on cholesterol intake and metabolism that should be pursued" to better understand how to prevent prostate cancers from having a poor prognosis.