THE "NEW" PROSTATE CANCER INFOLINK

“Evidence continues to mount that the use of statins is inversely correlated with the risk of [high grade] prostate cancer,” says Elizabeth Platz, co-director of the cancer prevention and control program at the Johns Hopkins Kimmel Cancer Center, who is quoted in a report on the HealthDay web site.

Statins are drugs like simvastatin (Zocor), atorvastatin (Lipitor), and rosuvastatin (Crestor) that have historically been used to lower the levels of cholesterol in patients at risk for certain types of heart disease. Two new reports and an editorial on the potential of statins to lower risk for cancer in general and prostate cancer in particular appear in the November issue of Cancer Epidemiology, Biomarkers and Prevention. In the editorial, Dr. Eric Jacobs of the American Cancer Society writes that, “These results should help dispel any lingering thoughts that low cholesterol may help cause cancer.” However, it should be immediately noted that neither of the two studies actually provides definitive proof that taking a statin can lower the probability that a well-defined group of men will get prostate cancer.

In the first article, Ahn et al. examine the relationship between total serum cholesterol and HDL cholesterol and the risk of overall and site-specific cancers among 29,093 men in the Finnish Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study cohort. This is an epidemiological study in which fasting cholsterol levels were assayed at baseline, and 7,545 incident cancers were identified during up to 18 years of follow-up. In this study:

• Higher total cholesterol concentrations were associated with an overall decreased risk of cancer, and this was particularly evident for cancers of the lung and liver.
• However, these associations were not significant when cases diagnosed during the first 9 years of follow-up were excluded.
• Higher HDL cholesterol levels were also associated with decreased risk of cancer, and this association was evident for cancers of the lung, prostate, liver, and hematopoietic system.
• The associations of HDL cholesterol with liver and lung cancers remained after excluding cases diagnosed within 12 years of study entry.

The bottom line is that (a) total cholesterol levels below the generally recommended level of 200 mg/dl were associated with an 18 percent higher overall risk of cancer, but the increased risk applied only to cases diagnosed in the early years of the study, and that (b) higher levels of “good” HDL cholesterol, the kind that protects coronary arteries, were associated with a 14 percent lower risk of all cancers over the entire length of the study. According to Dr. Demetrius Albanes, the senior author of this study, the first of these two findings “supports the idea that lower cholesterol levels are the results of undiagnosed cancers.”

The second study shows that men enrolled in the placebo arm of Prostate Cancer Prevention Trial with total serum cholesterol levels of < 200 mg/dl had a 59 percent lower risk of developing the most dangerous forms of prostate cancer.

Platz et al. analyzed data from 5,586 men ages ≥ 55 years who were randomized to the placebo arm of the Prostate Cancer Prevention Trial between 1993 and 1996. Their total serum cholesterol levels were measured at trial entry. By the end of follow-up, 1,251 prostate cancer cases were confirmed in this group of patients. Careful analysis of the available data suggests that:

• Men with a total cholesterol level < 200 mg/dl had a significantly lower risk of Gleason 8 to 10 prostate cancer than men with cholesterol levels ≥ 200 mg/dl.
• There was no association between total cholesterol level and prostate cancer risk overall, or for men with Gleason 2 to 6 disease, or for men with Gleason 7 disease.

Platz and her colleagues conclude that “men with low cholesterol have a reduced risk of high-grade prostate cancer.” She also clearly states that the association between low cholesterol levels and a reduced incidence of aggressive disease “is a notable reduction which is not often seen for prostate cancer.” However, Dr. Platz emphasizes that, “Cholesterol levels had no significant effect on the overall incidence of prostate cancer in the study.”

Filed under: Diagnosis, Prevention, Risk Tagged: | Prevention, risk, statins