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The Prostate Cancer Prevention Trial

  • Updated: 02/02/2011

The information and links on this page are no longer being updated and are provided for reference purposes only.


Main Objective

To see whether the drug finasteride (Proscarâ„¢) can prevent prostate cancer in men age 55 and older.

Enrollment Period

October 1993 - May 1997


18,882 men: 92 percent white, 4 percent African American, 4 percent other races/ethnicities


Men were randomly assigned to take either 5 milligrams of finasteride or a placebo (dummy pill) once daily for seven years. All men had an annual digital rectal exam and prostate-specific antigen (PSA) test. At the end of the seven years, men who had not been diagnosed with prostate cancer were asked to have a prostate biopsy to see if they were truly cancer free.

Criteria for Participation

  • Men, age 55 and older
  • General good health
  • No evidence of prostate cancer at beginning of trial
  • Prostate Specific Antigen (PSA) 3 ng/ml
  • Willing to have a prostate biopsy at the end of the study

Study Sites

222 centers, located in the United States and Canada

Additional Study Objectives

  • To determine if finasteride affects the stage and grade of prostate cancers
  • To see if finasteride affects the number of deaths from prostate cancer and the number of deaths from all cancers
  • To see if finasteride changes the occurrence and type of noncancerous prostate growth
  • To estimate the accuracy of digital rectal exam and PSA testing -- separately and together -- in detecting whether a man has prostate cancer
  • To measure how long-term treatment with finasteride affects a man's urinary and sexual function

Related Pages

  • The SELECT Prostate Cancer Prevention Trial
    A collection of material about SELECT (Selenium and Vitamin E Cancer Prevention Trial), which sought to determine whether these two dietary supplements could protect against prostate cancer.
  • Prostate Cancer Home Page
    NCI's gateway for information about prostate cancer.
  • Prostate Cancer (PDQ®): Prevention
    Expert-reviewed information summary about factors that may influence the risk of developing prostate cancer and about research aimed at the prevention of this disease. (Health professional version.)