Dr. Whang Comments: Proscar (Finasteride) has been used for many years for treatment of BPH (benign prostatic hyperplasia). The PCPT (prostate cancer prevention trial) showed that use of Proscar lead to significant decrease in prostate cancer occurrence compared to placebo. However, there was a concern that those who developed cancer while on Proscar seemed to develop a more aggressive form of prostate cancer.
There have been many debates as to why this is or should be the case. This report suggests that long-term, there is no increased risk of aggressive prostate cancer compared to placebo. This suggests that it may be safe to use Proscar to try to prevent prostate cancer.
Proscar does have other side effects, however, such as breast enlargement and mild sexual dysfunction. Please talk to your urologist about this study.
Long-term study of drug Finasteride shows safety, effectiveness in lowering prostate cancer risk
By Angela Townsend, The Plain Dealer
on August 16, 2013 at 6:00 AM, updated August 16, 2013 at 6:05 AM
Long-term study results released this week show the drug Finasteride lowers a man's prostate cancer risk without raising the risk of dying of the disease as earlier results hinted it might.AP
CLEVELAND, Ohio -- New data surrounding a drug used for years to treat an enlarged prostate and male pattern baldness is providing more evidence to show the drug's safety and effectiveness in reducing a man's risk of developing low-grade prostate cancer, researchers announced this week.
Data from a long-term follow-up study to the Prostate Cancer Prevention Trial, whose results were first published a decade ago, shows that finasteride is shown to reduce risk of prostate cancer by 43 percent and does not increase a man's risk of death. The drug also reduces the risk of a man developing prostate tumors by about 30 percent.
Dr. Ian ThompsonUT Health Science Center, San Antonio
"This gives us much more confidence as we treat men for prostate enlargement," said Dr. Ian Thompson Jr., director of the Cancer Therapy & Research Center at the University of Texas Health Science Center at San Antonio. "We can say that taking this medication is not going to reduce your life expectancy."
Thompson led the study, which analyzed data collected for 18 years. The results were published this week in the New England Journal of Medicine.
The study also underscores previous findings that the medication also improves the focus of prostate-specific antigen, or PSA, testing on aggressive cancers, he said.
Finasteride is a generic drug that lowers hormone levels that can contribute to the growth of prostate cancer. In 1992 the Food and Drug Administration approved the drug (brand name Proscar) to treat enlarged prostate. In 1997 the FDA approved a lower dose of the drug (brand name Propecia) to treat male pattern baldness.
Thompson led the multi-center Prostate Cancer Prevention Trial, a study funded by the National Cancer Institute that enrolled nearly 19,000 men at 222 different sites across the country. The trial, which began in 1993, studied whether finasteride could prevent prostate cancer. Men assigned to the finasteride group took the drug for seven years.
The trial showed that the drug significantly reduced the risk of prostate cancer. But initial results also showed that a slightly higher percentage of those on the drug developed high-grade cancer than those assigned to the group that took a placebo.
That observation was enough for the FDA not to grant approval of finasteride as a drug that could help prevent prostate cancer.
"It really put the damper on clinicians [wanting] to use the drug, and of patients wanting to take it," said Dr. Eric Klein, a urologist and chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic.
The difference between the finasteride and placebo groups shrank in follow-up analysis. Still, the earlier findings were enough of a concern that some physicians began prescribing the drug less frequently, or not at all.
In 2009 the American Society of Clinical Oncology and the American Urological Association issued ajoint guideline recommending that healthy men over age 55 who show no symptoms of the disease should talk to their doctors about using finasteride to lower their prostate cancer risk.
Even though the drug's ability to shrink the prostate helped to make the PSA test more effective in detecting cancerous tumors, the FDA in 2011 added a warning to the label about the increased risk of being diagnosed with high-grade prostate cancer.
"When [the FDA] said they were concerned about the high risk, I was concerned," Thompson said. But because the risk now appears to be "minimal to none," he said he hopes any new packaging labels will include the drug's benefits, and not just the risks.
Finasteride costs about $3 a pill. Because the FDA has yet to approved it as a cancer prevention drug, insurance companies may not cover it for that purpose. Diminished libido, erectile dysfunction and male infertility all have been reported as side effects, during use or after the drug has been discontinued.
For patients who have the conversation with their physician about whether the drug is right for them, that discussion is now backed up by solid data, Klein said.
"This should reassure everybody that drug is safe to take," he said. "Men are no more likely to die if they take drug or if they don't."