NEW DATA have confirmed that it is possible to prevent prostate cancer (PCa) in men using the 5-alpha-reductase inhibitor, finasteride. There had been previous concerns that the drug was in fact promoting the development of high-grade PCa; however, new follow-up results from the Prostate Cancer Prevention Trial (PCPT) have abolished these claims.
The U.S. Food and Drug Administration (FDA) issued a ‘black box’ warning about finasteride in 2011. This was because of the PCPT, one of the largest cancer prevention trials, with a total of 18,882 men included from 1993–1997. In this trial, the men were randomly selected to receive either finasteride or a placebo. The drug’s safety concerns stemmed from the trial finding that finasteride increased the risk of developing high-grade disease by 0.5% (1 in 200 men), despite reducing overall PCa risk by 25%.
However, since the original study, follow-up SWOG analyses have found further benefits of finasteride for prostate cancer patients. Finasteride improved detection of PCa, including high-grade tumours, and study participants experienced the same longevity whether taking finasteride or placebo. The researchers also matched up the study participants to the National Death Index, a death record database at the U.S. Centers for Disease Control and Prevention. The results showed that with approximately 300,000 person-years of follow-up and a median follow-up of 18.4 years, there were 42 deaths from PCa in patients receiving finasteride and 56 in those receiving placebo. “What we ultimately found were fewer prostate cancer deaths with finasteride, demonstrating with prolonged follow-up that there was no greater risk of prostate cancer death with the drug, just fewer cancers,” said Dr Ian Thompson Jr, President of CHRISTUS Santa Rosa Hospital Medical Center, San Antonio, Texas, USA. Dr Thompson added that, thanks to these results, physicians can confidently tell their patients that taking finasteride is a proven way of reducing the risk of PCa.
These data will significantly benefit men deemed at risk of developing PCa, as it will allow them to take the drug without fear that it will lead to the development of an aggressive tumour.