Reducing your risk of prostate cancer.
No one knows how to prevent prostate cancer, although researchers are studying it. The biggest known risk factors—such as age, family history and race—are not under your control. Lifestyle choices that you can control (such as diet, obesity and alcohol consumption) are still under investigation. One large study published in 2011 found that smokers diagnosed with prostate cancer had a greater risk of recurrence and death from the disease (though men who had quit at least 10 years before their diagnosis did not have this greater risk).
Could you take a supplement to prevent it? So far, the answer is unclear. Dietary supplements selenium and vitamin E were hypothesized to help prevent prostate cancer, but a large study—the first results of which were published in 2005—not only found no reduction in prostate cancer, but also a slight increased incidence in men taking vitamin E.
Scientists have also examined whether drugs currently used to treat prostate enlargement might also prevent prostate cancer. Two drugs, Proscar (finasteride) and Avodart (dutasteride), treat BPH by preventing the body’s ability to convert testosterone into a similar hormone called dihydrotestosterone (DHT). (Proscar at a much lower dose is the drug Propecia, which is prescribed to prevent hair loss.) Since male hormones encourage the growth of prostate cells, the theory is that reducing DHT may also keep early tumors from growing. Laboratory tests have also supported the idea.
One large study published in 2003 involved more than 18,000 men who were randomly assigned to take Proscar or a placebo. The trial was stopped ahead of schedule when men taking Proscar showed a nearly 25 percent reduction in prostate cancer prevalence. This would have been unabashedly good news had one troubling find not emerged: When men did get prostate cancer, the disease was more likely to be advanced. (Among men taking Proscar, 6.4 percent of cancers were advanced, compared with 5.1 percent of those taking the placebo.)
In 2010, researchers published results of a study with Avodart, which had similar findings. In a study that included almost 7,000 men, those who took Avodart for four years were about 23 percent less likely to be diagnosed with prostate cancer than those who did not take the drug. There was a slightly higher risk of more advanced cancer. In June 2011, the Food and Drug Administration recommended that the label for drugs such as Proscar and Avodart reflect a higher risk of developing a more advanced form of prostate cancer.
But some doctors have questioned whether the FDA needed to add the warning—subsequent analysis suggests that the drugs did not cause the high-grade cancers, but that the tumors may have become more detectable after the drugs shrank the size of the prostate. Both the American Society of Clinical Oncology and the American Urological Association recommend discussing use of the drugs with your physician.
One large study published in 2011 found that smokers diagnosed with prostate cancer had a greater risk of recurrence and death from the disease.