Statins Appear to Dramatically Reduce Prostate Cancer Risk
Two cancer researchers have found that the long-term use of cholesterol-lowering statins may dramatically reduce prostate cancer risk. Rakesh Singal, M.D., an oncologist at the University of Miami Sylvester Comprehensive Cancer Center and the Miami VA Medical Center, and Vikas Khurana, M.D., from the Louisiana State University Health Sciences Center, presented their findings at the annual meeting of the American Society of Clinical Oncology in Orlando this week. “This is really quite remarkable,” said Singal. “A 90 percent reduction in prostate cancer risk in men using statins for four years or more, and the fact that the risk is decreasing with duration of statin use, that is very strong data.”
Singal and Khurana analyzed a database of patient information from ten Veterans Affairs medical centers in four states – Louisiana, Mississippi, Texas, and Arkansas. They looked at 443,805 male patients from 1998 through 2004 and grouped them by whether or not they took prescription statins to lower cholesterol, and whether they were ever diagnosed with prostate cancer. In their control group, those men not taking statins, prostate cancer appeared at the national average. A total of 26,087 men were diagnosed with prostate cancer, but those men taking statins were significantly less likely to get the disease. The protective effect was apparent in men who had taken the drug for more than one year and increased with duration of statin usage. Men who took statins for more than four years were 90 percent less likely to be diagnosed with prostate cancer. The preventive effect applied after controlling for other risk factors such as age, diabetes, body type, race, and tobacco use.
“You’re killing two birds with one stone,” said Singal. “At the same time you’re preventing heart disease you are also preventing cancer.” At least six statins are on the market in the United States and the drugs have been shown to be largely safe for use over an extended period. Statins inhibit an enzyme called MHG-CoA reductase that restricts the production of low-density lipoproteins, or LDL or “bad” cholesterol. Statins are routinely prescribed to patients with cardiovascular disease. They are often as simple as taking a single pill late in the day. Some statin patients may suffer digestive problems, cramps, muscle pain, or abnormalities in the liver. On the other hand, previous studies have shown that statins may also strengthen bone density.
“Heretofore, doctors and scientists felt that the development of prostate cancer was largely, almost exclusively, related to male hormones and that these androgens promoted the growth of cancer cells and their withdrawal inhibited the growth of prostate cancer,” said Mark S. Soloway, M.D., chairman of Urology at the University of Miami Miller School of Medicine. He says this opens a whole new avenue of research. “Now we see that statins may have an effect on prostate cancer growth. This is becoming a more complex problem than we thought and there may be a number of minimally toxic treatments like this with far fewer side effects than we’ve seen in the past.”
Research presented at the American Association for Cancer Research in April showed that statin use appeared to reduce the risk of advanced prostate cancer. “One question that is commonly asked is, should we start prescribing statins for cancer prevention, and I would say, no, not at this stage, not yet,” said Singal. Since there are effective screenings to detect prostate cancer early, when it is highly treatable, statin use may call for a cautious approach. “One of the things we’ll do is a subgroup analysis to see whether statins can be useful in preventing aggressive prostate cancer,” said Singal. “If they do, that would be more meaningful because even with screening aggressive prostate cancers are problematic.”
Peter Greenwald, M.D., Dr.P.H., director of Cancer Prevention at the National Cancer Institute, plans to present the findings at the Best of ASCO conference, June 17 and 18 in San Francisco. The next step for Singal and Khurana is to publish their data and pursue a larger study. They hope, eventually, to enroll men with normal cholesterol in a randomized trial, with half getting statins, half not, and compare their prostate cancer rates. “If you can prevent the advancement of the disease rather than have to go in later and take it out,” said Soloway, “then we’re ahead of the game.”
“We had an idea that there was a correlation but this kind of effect was very convincing,” said Singal. “These results were unanticipated — we did not think it would be so strongly positive. Before this we had an underlying idea that prostate cancer risk could be reduced in patients taking statins but this kind of effect is very convincing.”
UM/Sylvester was founded in 1992 to provide comprehensive cancer services and today serves as the hub for cancer-related research, diagnosis, and treatment at the University of Miami Leonard M. Miller School of Medicine. UM/Sylvester handles more than 1,300 inpatient admissions annually, performs 2,900 surgical procedures, and treats 3,000 new cancer patients. All UM/Sylvester physicians are on the faculty of the Miller School of Medicine, South Florida’s only academic medical center. In addition, UM/Sylvester physicians and scientists are engaged in more than 150 clinical trials and receive more than $31 million annually in research grants. UM/Sylvester at Deerfield Beach recently opened to better meet the needs of residents of Broward and Palm Beach counties. This 10,000-square-foot facility at I-95 and S.W. 10th Street offers appointments with physicians from six cancer specialties, complementary therapies from the Courtelis Center, and education and outreach events.