Several recent papers have suggested that statins, medications for cholesterol such as Lipitor and Zocor, may impact prostate cancer development and progression. Considering that these drugs have revolutionized the prevention of heart disease, could these drugs truly killing two birds with one stone? We would like to think so, and although this is exciting news, we need to be careful in how we interpret these findings. It remains too early to recommend starting men on statins to prevent prostate cancer.

Statins for prostate cancer: Pro

Supporting the claim that statins can control prostate cancer growth are several recent studies. Animal studies, which are used to test if a drug may have a certain effect, have demonstrated that high doses of statins can slow the growth of prostate cancer. Large studies of men on statins for heart disease have shown decreased rates of advanced prostate cancer. Statins have been suggested to reduce patients' PSA levels prior to treatment, suggesting that they are influencing the biology of prostate cancer.

One recent paper by a group from Duke University showed that patients who were on statins at the time of prostate cancer surgery had lower rates of recurrence compared to those who were not. Another publication demonstrated the same results following radiation treatment for prostate cancer. Since recurrence can lead to worse outcomes such as metastasis and death, preventing recurrence is important. Additionally, these effects appear to be dose related, meaning that patients taking higher doses of statins had lower rates of recurrence. This further supports the idea that the drugs are actually influencing the cancer.

Statins for prostate cancer: Con

The studies described above have been relatively small in terms of the number of patients that were studied. For example, the study that demonstrated a reduction in recurrence after prostate cancer surgery only had 236 men in the statin group and almost all were on one specific statin: simvastatin. Larger epidemiologic studies, including some with up to 90,000 men, have not shown any reduction in diagnosis of prostate cancer, although some have shown decreased rates of diagnosis of advanced disease (as discussed above).

Perhaps the most important weakness in all of these studies, however, is that they are all observational or epidemiologic in nature. This means that they were not designed to look at the question we want to answer, in this case, whether statins impact prostate cancer growth and progression. It is possible that there are other factors that may result in men on statins developing prostate cancer at different rates, including the fact that men on statins see their doctor more often and have routine bloodwork that could include a PSA test.

Ideally, we would start one group of men at random on statins and another group on placebo after prostate cancer surgery. Then we would follow them to see if the statin group had lower rates of recurrence. This so-called "randomized controlled trial" is the only way to truly know whether drugs have the effect we are studying. Otherwise, there are too many unknown variables that could be impacting the prostate cancer.

Until we have this kind of information, we cannot recommend using statins to prevent prostate cancer. This is not a theoretical concern, as the medical community has been burned by this problem more than once before. The most prominent example concerned the use of hormone replacement therapy (HRT) and breast cancer. Epidemiologic evidence suggested that HRT reduced the risk of breast cancer, and millions of women were started on it for this reason. Later, randomized studies showed that HRT actually INCREASED the risk of breast cancer. Thousands of women stopped taking HRT, and shortly thereafter, the rate of breast cancer in the U.S. decreased.

In conclusion, statins show promise in preventing the development and growth of prostate cancer. Men on statins for their cholesterol should be happy to hear this, although it is too early to recommend starting a man with normal cholesterol on a statin to prevent prostate cancer.