Declining PCa mortality correlates to increased rates of high cholesterol

A search for reasons behind the decline in prostate cancer mortality since the mid-1990s revealed two of the usual suspects-PSA screening and access to health insurance-but also uncovered an unlikely and totally unexpected lipid factor.

"The results of our study suggest that declining prostate cancer mortality is associated with increased rates of PSA screening for Caucasian males, increased rates of health insurance coverage for African-American males, and, unexpectedly, increased rates of high cholesterol in Caucasian males," said Sean Clark, MD, of the University of Alabama and Veterans Affairs Medical Center in Birmingham.

The findings emerged from a review of prostate cancer mortality data for 1993 to 2003 among men >50 years of age in the National Vital Statistics System. Prostate cancer mortality declined steadily during the period reviewed, and in 2006, prostate cancer dropped to the No. 3 cause of cancer death in the United States, replaced by colorectal cancer as No. 2 behind lung cancer.

The data were analyzed with respect to the potential influence of PSA screening, health insurance coverage, obesity, physical inactivity, diabetes, and high cholesterol levels. The analysis showed a statistically significant inverse correlation among Caucasian men between prostate cancer mortality and PSA screening (R=-0.28, p=.05) and elevated cholesterol levels (R=-0.42, p=.002). The only significant factor among African-American men was increased rates of health insurance coverage (R=-0.43, p=.03).

Calling the association between high cholesterol and reduced prostate cancer mortality risk counterintuitive, Dr. Clark said one possible explanation is the rapid expansion of treatment with statin drugs during the same time period. Considerable overlap exists between men who have cardiovascular indications for statin therapy and the at-risk population for prostate cancer, he noted, and experimental evidence suggests that statins have antiproliferative and possibly other anticancer effects.