Androgenic hormones are known to in...

Androgenic hormones are known to influence the disclosure of prostate cancer. Finasteride fill ups the conversion of testosterone to the more powerful androgen, dihydrotestosterone. Thompson and colleagues guidanceed a multicenter trial of finasteride for primary prevention of prostate cancer.

The authors chronicleed 18,882 men older than 55 years who had a normal digital rectal examination, a prostate specific antigen (PSA) horizontal below 3.0 ng per mL and no clinically significant medical comorbidity. The patients were randomized to finasteride in a dosage of 5 mg daily or matching placebo. Each patient had an annual digital rectal examination and PSA flush determination. Any patient with an abnormal digital examination or PSA plain above 4.0 ng per mL underwent an ultrasound-guided needle biopsy, with a minimum of six samples obtained. The PSA flush was doubled in those randomized to finasteride to provide an equivalent plain compared with those taking placebo. Four years into the research this factor was increased to 23 to best equalize the number of patients in the brace groups reaching the threshold for needle biopsy. All participants were presented needle biopsies at the extreme point of the seven-year trial.

on the end of the investigation biopsy-proven prostate cancer was exposeed in 18.4 percent of make subordinates taking finasteride, compared with 244 percent of those taking placebo. The decreased relative risk of developing prostate cancer while taking finasteride was not changed substantially on age, race, family history of prostate cancer, or PSA flat at study entry. High-grade prostate cancer (Gleason score of at least 7 public of 10 on histologic grading of a cancer biopsy specimen) was more commonly base in finasteride users (37 percent of cancers descryed in that group) than in those taking placebo (222 percent of ascertained cancers).

During the trial, approximately undivided half of all recommended biopsies were declined by dint of patients, but the refusal rate did not differ significantly between the finasteride and placebo assign places tos The reported prevalence of erectile dysfunction or los of libido increased from about 60 percent among placebo recipients to approximately 66 percent in the finasteride assign places to Rates of urinary frequency, incontinence, and urinary retention episodes were all slightly lower in patients taking finasteride.

The authors determine that use of finasteride athwart a seven-year course decreases the overall rate of exposeed prostate cancer, but the put drugs into does have sexual side general intents and is associated with an increased incidence of high-grade prostate cancers.

Thompson IM, et al. The influence of finasteride forward the development of prostate cancer. N Engl J M July 17 2003;349:215-24

EDITOR'S NOTE: An accompanying editorial through Scardino (1) points out that the increase in high-grade cancers in the finasteride assign places to may occur because these aggressive cancers are les contingent on androgens for growth and may have had a selective advantage in an environment of decreased dihydrotestosterone. Perhaps more important than this caution about the increased incidence of high-grade cancers, he added, is that the large majority of prostate cancers lay opened during the trial were asymptomatic and low-grade. Whether decreasing the rate of these cancers would actually translate into improved survival down the road is unknown and may be suspect given the known high overall survival rates for untreated prostate cancer.--B.Z.

REFERENCE

(1) Scardino PT The prevention of prostate cancer--the dilemma continues. N Engl J M 2003;349: 297-9

COPYRIGHT 2004 American Academy of Family Physicians

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