my personal edition > prostate cancer > news


  E-Mail this DGReview to a colleague

DGReview

Finasteride Treatment Associated with Lower Incidence of Prostate Cancer, But Also Higher Risk of High-Grade Disease and Sexual Dysfunction

Finasteride effectively prevents prostate cancer and reduces urinary symptoms in men over 55, but its use is also associated with sexual side effects and an increased risk of high grade prostate cancer, according to a recent American study.

Early diagnosis and treatment are currently the most effective measures in the management of prostate cancer. Preventive strategies are the next step in decreasing the overall incidence.

It is well known that androgens affect the development of prostate cancer. It is therefore thought that finasteride, which inhibits the production of dihydrotestosterone the primary androgen in the prostate, may reduce the cancer risk.

Ian M Thompson, MD, from the University of Texas Health Science Centre, San Antonio, United States, and colleagues evaluated the use of finasteride in initially healthy men.

The study included 18,882 men over the age of 55 who had a normal digital rectal examination and a prostate-specific antigen (PSA) level under 3.0 ng/mL. Patients were randomised to receive finasteride (5 mg/day) or placebo for 7 years. Examinations were performed annually and prostate biopsy was recommended if the PSA level was higher than 4.0 ng/mL or if digital rectal examination gave abnormal results. Biopsy was performed at the end of the study in all patients.

By 7-year follow up, including end-of-study biopsy, 18.4% of men receiving finasteride were diagnosed with prostate cancer compared to 24.4% of men receiving placebo. This represented a 24.8% relative risk reduction in prostate cancer over 7 years (P<.001).

Despite the decreased prevalence of prostate cancer with finasteride treatment, there was an increased incidence of high grade prostate cancer. Specifically, tumours of Gleason grade 7 to 10 were found in 6.4% of men taking finasteride and in 5.1% of those taking placebo (P=.005).

Furthermore, finasteride-treatment was associated with various symptoms of sexual dysfunction. Men taking finasteride more commonly reported reduced volume of ejaculate, erectile dysfunction, loss of libido, and gynecomastia.

However, finasteride treatment was also associated with a reduction in urinary symptoms, wherein fewer reports of urinary urgency or frequency, prostatitis, urinary tract infection, and urinary retention were made compared to placebo.

The authors conclude that "finasteride prevents or delays the appearance of prostate cancer, but this possible benefit and a reduced risk of urinary problems must be weighed against sexual side effects and the increased risk of high-grade prostate cancer." They further state that "physicians can use these results to counsel men regarding the use of finasteride."


N Engl J Med 2003;349:3:215-24. "Finasteride to prevent prostate cancer?"

E-Mail this DGReview to a colleague

To print, use this version