Final verdict on finasteride: Safe, effective prevention for prostate cancer

Finasteride, a generic hormone-blocking drug, was found to reduce the risk of prostate cancer by 25 percent in the landmark Prostate Cancer Prevention Trial (PCPT). Long- term data, published today in the New England Journal of Medicine, show that reduction in prostate cancer risk has continued and fewer than 100 men on the trial died from the disease.

SWOG Cancer Research Network, an international cancer clinical trials group funded by the National Cancer Institute (NCI), part of the National Institutes of Health, opened the PCPT for enrollment 25 years ago. The PCPT enrolled 18,882 men from 1993 to 1997, making it one of the largest prostate cancer clinical trials ever conducted. New results, which reported participant deaths over two decades, show that finasteride has the lasting effect of reducing prostate cancer risk. Results also eliminate concerns over initial findings of a possible risk of more aggressive cancers with finasteride use.

"Finasteride is safe, inexpensive, and effective as a preventive strategy for prostate cancer," said Ian Thompson, Jr, MD, principal investigator of the PCPT for SWOG. "Doctors should share these results with men who get regular prostate-specific antigen tests that screen for the presence of prostate cancer. The drug will have its greatest effect in this group of men."

Thompson is chair of SWOG's genitourinary cancer committee and serves as president of CHRISTUS Santa Rosa Hospital - Medical Center in San Antonio, Texas and as emeritus professor at the University of Texas Health Science Center. Along with SWOG biostatisticians Catherine Tangen, DrPH, and Phyllis Goodman, MS, of Fred Hutchinson Cancer Research Center, Thompson sought to determine whether the increased number of high-grade cancers detected through the PCPT years ago would result in more prostate cancer deaths over time.

SWOG published the first PCPT results in 2003. Investigators reported a significant, positive result: finasteride reduced prostate cancer risk by 25 percent. But the study also cast a shadow on the drug, the first 5-alpha-reductase inhibitor which targets and blocks the action of androgens like testosterone and is commonly used to treat lower urinary tract problems in men and also male pattern baldness. The results showed that finasteride increased the number of high-grade prostate cancers - a finding that resulted in a drug label warning posted by the U.S. Food and Drug Administration. That warning persists to this day.

So is finasteride safe in the long run? Thompson, Tangen, and Goodman matched participants to the National Death Index, a centralized database of death record information managed by the U.S. Centers for Disease Control and Prevention. This analysis allowed the SWOG team to determine if a trial participant had died, and if so, the cause of death. With almost 300,000 person-years of follow-up and a median follow-up of 18.4 years, they found 42 deaths due to prostate cancer on the finasteride arm and 56 on the placebo arm. Thus, there was no statistically significant increased risk of prostate cancer death with finasteride.

In the NEJM letter, the team notes that a cheap, reliable prostate cancer prevention drug will have a big impact on public health. Due to a rise in screening for the disease, prostate cancer diagnoses are on the rise, with the American Cancer Society estimating that 164,690 American men would be diagnosed in 2018. While many of these cancers will be slow-growing, and not life-threatening, they are still often treated with surgery and radiation, resulting in common complications such as impotence and incontinence.

"There are significant negative consequences to patients' health and quality of life that can result from prostate cancer treatment, as well as to their finances and their peace of mind," Thompson said. "If we can save people from surgeries, and scores of examinations and tests, and spare them from living for years with fear, we should. The best-case scenario for patients is prevention, and this trial has found an inexpensive medication that gets us there."

The NCI and the National Institutes of Health funded the study through grants CA037429 and CA182883.

Other members of the SWOG study team include Amy K. Darke, MS, of Fred Hutch; M. Scott Lucia, MD of University of Colorado, Denver; Leslie G. Ford, MD, of the Division of Cancer Prevention at the NCI; Lori M. Minasian, MD, of the Division of Cancer Prevention at the NCI; Howard L. Parnes, MD, of the Division of Cancer Prevention at the NCI; and Michael L. LeBlanc, PhD, of Fred Hutch.

SWOG Cancer Research Network is part of the National Cancer Institute's National Clinical Trials Network and the NCI Community Oncology Research Program, and is part of the oldest and largest publicly-funded cancer research network in the nation. SWOG has nearly 12,000 members in 46 states and six foreign countries who design and conduct clinical trials to improve the lives of people with cancer. SWOG trials have led to the approval of 14 cancer drugs, changed more than 100 standards of cancer care, and saved more than 3 million years of human life.

Most Popular Now

Compound that kills drug-resistant fungi is isolat…

Antimicrobial and antifungal resistance, which describe the ability of bacteria and other pathogens to resist the effects of drugs to which they were once sensitive, is a...

Novartis receives FDA approval for Mayzent® (sipon…

Novartis today announced that the US Food and Drug Administration (FDA) has approved Mayzent® (siponimod) for the treatment of adults with relapsing forms of multiple scl...

First bacterial genome created entirely with a com…

All the genome sequences of organisms known throughout the world are stored in a database belonging to the National Center for Biotechnology Information in the United Sta...

Liver, colon cancer cells thwarted by compounds de…

The plant that adds flavor, color and bitterness to beer also produces a primary compound that thwarts cancer cells, and two important derivatives of the compound do as w...

Immune cells fighting blood cancer visualized for …

When cancer escapes the immune system, our defenses are rendered powerless and are unable to fight against the disease. Chimeric antigen receptor T cells (CAR T cells) re...

Clinical trial finds therapy to be well-tolerated …

A phase I clinical trial that set out to assess the safety of a new combination therapy for a type of aggressive brain tumour has found the treatment to be well tolerated...

FDA approves treatment for patients with a type of…

The U.S. Food and Drug Administration today approved Cimzia (certolizumab pegol) injection for treatment of adults with a certain type of inflammatory arthritis called no...

Selumetinib granted US Breakthrough Therapy Design…

AstraZeneca and MSD, Inc., Kenilworth, NJ, US (MSD: known as Merck & Co., Inc. inside the US and Canada) today announced that the US Food and Drug Administration (FDA) ha...

Boehringer Ingelheim announces FDA and EMA regulat…

Boehringer Ingelheim has filed for regulatory approval of nintedanib in patients with systemic sclerosis associated interstitial lung disease (SSc-ILD) with the FDA and E...

Novartis adds clinical and preclinical anti-inflam…

Novartis announced that it is adding to its broad portfolio of immunomodulatory medicines with the planned acquisition of IFM Tre, a subsidiary of IFM Therapeutics LLC fo...

Novartis continues transformation into a leading m…

Novartis today completed the spin-off of the Alcon eye care devices business through a dividend-in-kind distribution to holders of Novartis shares and ADRs (American Depo...

Forxiga approved in Japan for type-1 diabetes

The Japanese Ministry of Health, Labour and Welfare (MHLW) has approved Forxiga (dapagliflozin) as an oral adjunct treatment to insulin for adults with type-1 diabetes (T...