Serum lipid levels and post-surgical risk for prostate cancer recurrence

According to an article published today in Cancer Epidemiology, Biomarkers and Prevention, men with dyslipidemia (an abnormal lipid profile) and elevated total cholesterol levels who have surgery for prostate cancer are at significantly increased risk for prostate cancer recurrence.

The paper by Allott et al. looked at data from 843 men at six different VA Medical Centers across America who all received a radical prostatectomy after a diagnosis of prostate cancer and who never received statin therapy prior to their surgery (between 1999 and 2013).

Study findings included the following:

  • Among the 843 patients studied,
    • 343 (40.7 percent) were African-Americans.
    • 325 (38.6 percent) had abnormal cholesterol levels.
    • 263 (31.2 percent) had abnormal triglyceride levels.
    • 293 (34.8 percent) had a biochemical recurrence (i.e., a rising PSA level after their surgery).
  • Compared to men with normal, pre-surgical, total cholesterol levels (≤ 200 ng/ml), these 843 men with elevated, pre-surgical, total cholesterol levels were significantly more likely to receive statin therapy post-surgery.
  • There was no association between the patients’ total cholesterol levels and risk for prostate cancer recurrence.
  • Among the patients with an abnormal blood lipid profile,
    • For every increase in serum triglyceride levels of 10 mg/dl, there was a 2 percent increased risk for prostate cancer recurrence.
    • For every increase in total serum cholesterol of 10 mg/dl above 200 mg/dl, there was a 9 percent increased risk for prostate cancer recurrence.
  • Compared with patients who had normal levels of triglycerides, men with serum triglyceride levels of ≥ 150 mg/dl had a 35 percent increased risk for prostate cancer recurrence.
  • Among the patients with abnormally low levels of high density lipoprotein  or HDL — the so-called “good” cholesterol (i.e., men with an HDL level of < 40 mg/dl), for every increase in HDL of 10 mg/dl there was a 39 percent decreased risk for prostate cancer recurrence.

Allott is quoted as follows in a media release issued by the American Association for Cancer Research:

While laboratory studies support an important role for cholesterol in prostate cancer, population-based evidence linking cholesterol and prostate cancer is mixed.  Understanding associations between obesity, cholesterol, and prostate cancer is important given that cholesterol levels are readily modifiable with diet and/or statin use, and could therefore have important, practical implications for prostate cancer prevention and treatment.

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.

8 Responses

  1. This is a good example of misinterpreting research on the part of the study’s authors. The authors jump to the unwarranted inference, “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.” Their findings suggest nothing of the kind.

    Association is not causation. It is more plausible that a biochemical/genetic abnormality is driving both high lipid levels and the risk of prostate cancer. If that is the case, reducing serum lipid levels will do nothing to effect PC recurrence. The very inconsistent findings on many such studies reflect this. See, for example, “Drug repurposing for advanced PC 7. Statins.”

    Until the results of prospective, randomized, clinical trials are available, data analyses like this are only useful to generate hypotheses, but are not useful for guiding treatment decisions. On the other hand, low doses of lipid-soluble statins are reasonably safe for most men, and may be good insurance in spite of the lack of definitive findings. More importantly, there are many other good reasons to take statins when lipids are elevated.

  2. Dear Allen:

    All the authors state is, in fact, an hypothesis. That’s why they use the critical word “may” in the statement you quote.

  3. A good scientist will state alternative hypotheses that explain the observation, not just the one it “suggests” to them. Fortunately, there are randomized clinical trials in the works. I see studies like this all the time. The danger of single conclusions like this is that the media pick it up and write about it as established fact, and suddenly everyone thinks that all they need to do to prevent recurrence is to take statins.

    Here’s a sample of some of today’s headlines/leadlines:

    — Triglycerides Hike Prostate Cancer Recurrence: “Having high triglycerides after radical prostatectomy raises the risk of cancer recurrence, researchers found.”

    — High Cholesterol and Fat Levels Increase Prostate Cancer Recurrence Risk, Study: “High levels of cholesterol and triglycerides in blood increase the risk of prostate cancer recurrence, according to a Duke University study.”

    — High Levels of Cholesterol and Triglycerides Up Risk of Prostate Cancer Recurrence: “A new study states that elevated levels of total cholesterol and triglycerides in the blood can up the risk of prostate cancer recurrence.”

    I believe that such misinformation might not have occurred if the researchers had been more careful in stating their conclusions.

  4. Dear Allen:

    The inability of the media to miss the opportunity to over-stress one perspective in order to “sell newspapers” (or perhaps more accurately to “draw attention to their media and help to sell advertising space”) is hardly confined to the world of prostate cancer.

    I don’t think you can blame the researchers for this … although perhaps you could reasonably blame the organization responsible for sending out the media release designed to seek media coverage. My bet would be that many of those who reported on this story didn’t actually read the entire article, but just lifted text from the media release.

  5. Could be the statins are causing the prostate cancer recurrence.

  6. Dear Archie:

    I am not sure why you think that might be the case, but it seems unlikely in the extreme.

  7. I don’t really think that might be the case. Just making a statement on possible associations in the data that weren’t addressed. Statin use is of course associated with dyslipidemia and might therefore be associated with recurrence in the data of this study. We don’t know.

    BTW, I am in the category of post-prostatectomy with slowly rising PSA, so I have a keen interest. I have tried different diets but there is no magic bullet here. So far I have seen nothing in this study that would make me ask my doctor for a prescription for statins.

    Thanks for listening.

  8. Archie:

    There are, however, a number of other, data-based articles that dfo quite certainly suggest that patients receiving treatment with statins are at reduced risk for prostate cancer progression after first- and second-line treatment (although none of those articles are based on data from randomized, controlled clinical trials). I have yet to see any article suggesting that statin therapy increases risk for recurrence.

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