New study [1]. Somewhat perplexing.
It has been known for a century that solid tumors accumulate cholesterol. In PCa, cholesterol within cancer cells can be used to generate androgens. And, if cholesterol uptake is inhibited, the cells can manufacture cholesterol (unless prevented via a statin.)
"REDUCE was a four-year multi-center study testing the effect of daily Dutasteride {Avodart} on PC risk in men with a PSA of 2.5 to 10.0 ng/mL and a negative biopsy, with men undergoing study-mandated biopsies at 2- and 4-years." [2]
In Supplementary Table 3 of the new study, we find these odd associations with high-grade PCa:
- high LDL = 24% reduced risk
- high HDL = 64% increased risk
- high total cholesterol = 27% increased risk
The head of the new study was Steve Freedland, for whom I have a high regard.
It's a pity that they did not measure VLDL-C, i.e. very-low-density lipoprotein cholesterol. VLDL-C is supposedly readily taken up by PCa cells, whereas HDL-C is not. (Size matters.)
I don't believe that cholesterol is a risk factor for PCa. Seems to me that when PCa is of an aggressive type, an abundance of cholesterol is associated with its promotion. My first thought was that high cholesterol is related to the metabolic syndrome [MetS] - but MetS is also associated with lower HDL-C. Even so, the available data probably included triglycerides. The triglycerides:HDL-C ratio is a surrogate for insulin resistance. It would be interesting to see adjusted numbers, after controlling for insulin resistance.
Perhaps someone out there has a theory?
-Patrick
[1] nature.com/articles/s41391-...
Prostate Cancer and Prostatic Diseases
Article
Serum cholesterol and risk of high-grade prostate cancer: results from the REDUCE study
Juzar Jamnagerwalla, Lauren E. Howard, […]Stephen J. Freedland
Prostate Cancer and Prostatic Diseases (2017)
doi:10.1038/s41391-017-0030-9
Cancer epidemiologyCancer prevention
Received:
14 October 2017
Accepted:
13 November 2017
Published online:
27 December 2017
Abstract
Background
Epidemiologic evidence for a serum cholesterol-prostate cancer link is mixed. Prostate-specific antigen (PSA) is positively correlated with cholesterol, potentially increasing PSA-driven biopsy recommendations in men with high cholesterol, though biopsy compliance may be lower in men with comorbid conditions. These potential biases may affect PSA-driven biopsy rates and subsequent prostate cancer detection in men with high serum cholesterol. Our objective was to test the association between serum cholesterol and prostate cancer risk in men receiving PSA independent, study-mandated prostate biopsies.
Methods
We conducted a post hoc analysis of data from 4974 non-statin users in REDUCE, a randomized trial in men with elevated PSA and a negative baseline biopsy. Men underwent 2- and 4-year trial-mandated prostate biopsies. Associations between baseline serum levels of total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and prostate cancer risk, overall and by Gleason grade (<7 vs. ≥7), were examined using multivariable logistic regression.
Results
High total serum cholesterol was associated with an increased risk of high-grade prostate cancer diagnosis (OR per 10 mg/dL 1.05; 95% CI 1.00–1.09; p = 0.048), but cholesterol was unrelated to either overall or low-grade prostate cancer risk (p-values >0.185). There was no association between serum LDL and overall, low- or high-grade prostate cancer risk (p-values >0.137). In contrast, elevated serum HDL was associated with increased risk of both overall (OR per 10 mg/dL 1.08; 95% CI 1.01–1.16; p = 0.033) and high-grade prostate cancer (OR per 10 mg/dL 1.14; 95% CI 1.01–1.28; p = 0.034).
Conclusions
In REDUCE, where all men received PSA independent, trial-mandated biopsies thus ensuring complete prostate cancer ascertainment, high total serum cholesterol and high HDL were associated with increased risk of high-grade prostate cancer, supporting a cholesterol-prostate cancer link.
...