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The Prostate Cancer Prevention Trial

  • Updated: 02/02/2011

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The information and links on this page are no longer being updated and are provided for reference purposes only.

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.)


Main Objective

To see whether the drug finasteride (Proscar™) 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