Higher levels of triglycerides and cholesterol in the blood may signal an increased risk of recurrence for men with prostate cancer.
When abundant, two types of fat molecules circulating in the blood-triglycerides and cholesterol-may increase the risk of recurrence for men with prostate cancer, according to a new study funded by the National Institutes of Health. The results of the study were published in Cancer Epidemiology, Biomarkers & Prevention.
“Our findings suggest that normalization, or even partial normalization, of serum lipid levels among men with dyslipidemia may reduce the risk of prostate cancer recurrence,” said study author Emma Allott, PhD, a postdoctoral associate at Duke University School of Medicine in Durham, North Carolina, in a statement.
Patients who had serum triglyceride levels of 150 mg/dL or higher had a 35% increased risk for prostate cancer recurrence compared with patients who had normal triglyceride levels. Of the patients who had higher blood lipid levels, for every 10 mg/dL increase in total serum cholesterol above 200 mg/dL, there was a 9% increased risk for prostate cancer recurrence, according to the analysis.
For every 10 mg/dL increase in what is known as “good” cholesterol-high-density lipoprotein (HDL)-in men who had an abnormally low HDL level (below 40 mg/dL), the relative decrease in risk of disease recurrence was 39%. The total serum cholesterol, low-density lipoprotein (LDL), and HDL were not associated with a risk of recurrence in all men in the study population as a whole.
These results are based on a retrospective cohort analysis of 843 men who were diagnosed with prostate cancer and had a radical prostatectomy. None of the men in the study had taken statins prior to their surgery. A total of 35% (293 men) had biochemical recurrence after a median follow-up of 74.3 months.
“Given that 45% of deaths worldwide can be attributed to cardiovascular disease and cancer, with prostate cancer being the second most common cause of male cancer deaths in the United States, understanding the role of dyslipidemia as a shared, modifiable risk factor for both of these common causes of mortality is of great importance,” said Allott.
Prior studies have shown that cancer cells use and metabolize fat molecules, including cholesterol, differently from normal cells. Cholesterol in particular may contribute to prostate cancer progression, as it has been shown to play a role in the signaling during normal prostate cell growth and during prostate cancer growth. Yet, epidemiology studies of prostate cancer patients have led to varying results on the link between cholesterol and prostate cancer.
One study, published last year, showed that among men with prostate cancer, those who were already taking statins had a lower risk of dying from their prostate cancer compared with men who were not taking statins. Still, for prostate cancer patients who are taking statins, the precise benefit is not clear, nor is it clear how diet, obesity, and blood lipid levels affect development and progression of the disease. Statins are currently not recommended for treatment or prevention of prostate cancer.
“Although it cannot be determined from this study if these observed associations are causal, given the biological evidence supporting an important role of cholesterol in prostate cancer growth, in addition to epidemiologic data demonstrating that statin use is associated with reduced risk of recurrence, we believe that serum lipid levels should be explored further as a risk factor for prostate cancer recurrence,” concluded the study authors.