High Cholesterol Tied to Prostate Cancer's Return in Study

After surgery for prostate cancer, elevated levels of cholesterol and triglycerides may be linked with greater risk of the cancer's return, a new study from Duke University School of Medicine suggests.

In a review of more than 800 men who had had their prostate gland removed, those with higher levels of these two blood fats were more likely to have their cancer come back, compared with men with normal levels.

These findings suggest that normalization, or even partial normalization, of blood fats among men with high cholesterol and triglycerides may reduce the risk of prostate cancer recurrence. Cholesterol levels can be modified by diet or use of drugs called statins.

The research team also found that increases in high-density lipoprotein (HDL), the "good" cholesterol, benefited some men. For every 10 milligrams per deciliter (mg/dL) increase in men with abnormal HDL, the risk for prostate cancer recurrence dropped by 39 percent, they said.

But the chief of radiation oncology at Brigham and Women's Hospital in Boston, expressed a note of caution. "This is a study of association, not causality," he said, noting it doesn't prove that normal blood-fat levels prevent cancer recurrence.

Other clinicians, who wasn't involved in the study, does not recommend that men take statins to protect themselves from prostate cancer based on this study or similar research.

A clinical trial that compares statins, such as Lipitor, with placebo (sham) drugs to specifically test whether or not they reduce the risk of prostate cancer is needed before these drugs can be recommended for prevention of cancer or its recurrence.

This reluctance is based on disappointing results from trials that found no benefit from other associations that had looked promising.

There might be ways to modify risk factors for prostate cancer recurrence that need to be studied. But this study doesn't prove that lowering cholesterol works.

The study was published Oct. 10 in Cancer Epidemiology, Biomarkers & Prevention.

Among the 843 men in the study, 325 had abnormal cholesterol levels, 263 had abnormal triglyceride levels, and 293 had a recurrence of prostate cancer, according to the report.

Men who had triglyceride levels of 150 mg/dL or higher had a 35 percent increased risk of their cancer coming back, compared with men with normal triglyceride levels, the researchers found.

Moreover, every 10 mg/dL increase in cholesterol above 200 mg/dL was linked with a 9 percent increase in risk for the return of prostate cancer, the researchers said.

Understanding the role of high cholesterol as a modifiable risk factor for both heart disease and cancer, the most common causes of death, is of great importance.

Approximately 45 percent of deaths worldwide are attributable to heart disease and cancer, and prostate cancer is the second most common cause of cancer death among American men.

SOURCES: Emma Allott, Ph.D., postdoctoral associate, Duke University School of Medicine, Durham, N.C.; Anthony D'Amico, M.D., Ph.D., chief, radiation oncology, Brigham and Women's Hospital, Boston; Oct. 10, 2014, Cancer Epidemiology, Biomarkers & Prevention