For Cause Prostate Biopsy in REDUCE Population Trial
Condition: Prostate Cancer
MeSH terms: Prostatic Neoplasms
Study type: Observational

Summary: 
      The REDUCE trial was conducted to determine whether dutasteride reduces the risk of incident
      prostate cancer, as detected on biopsy, among men who are at increased risk for the disease.
      Dutasteride was compared with placebo for 4 years period. Results showed a relative risk
      reduction of 22.8 % (95% CI: 15.2 to 29.8)in prostate cancer.

      For REDUCE, biopsies were defined as "protocol biopsy" if performed at certain timeframes,
      and "for cause" if outside these predetermined timeframes.

      The investigators propose a post hoc analysis that would allow them to include biopsies that
      really justified a clinical indication, but were excluded from "for cause" analysis based on
      occurring at either the 2 or 4 year timeframes.

      Thus the investigators propose analysis of both REDUCE groups by every yearly timeframe as:

      Group 1--dutasteride group biopsied "for cause" using several definitions: biopsy of patients
      who received dutasteride whose PSA rose from nadir as defined in your own protocol,who had a
      PSA rise>0.2 ng/ml or who had a new abnormal DRE or had a free PSA<12% . The investigators
      define these as such because this would reasonably instigate biopsy if the clinician had a
      patient with this scenario in the non-study setting.

      Group 2--placebo group biopsied "for cause" using several definitions, regardless of
      timeframe but reported at each year of the study and aggregate, with the aggregate number
      being the primary outcome. Thus the investigators would request results of biopsy of patients
      who received placebo To establish differences in biopsy positive rates the groups as per each
      definition listed, to determine if dutasteride decreased the likelihood of "for cause" biopsy
      compared to "not for cause" biopsy, and if there is a difference in cancer detection risk
      rate depending on cause vs. no cause in that group compared to placebo.
    

Detailed description: 
      Purpose: Determining the likelihood of prostate cancer detection in men taking dutasteride
      when biopsy is performed 'for cause'.

      Population: The population of interest is the REDUCE Biopsied population, that is, all
      subjects in the Efficacy population who have at least one post-baseline biopsy reviewed by
      the Central Pathology Laboratory.

      Analyses: Initial interest will be focused on data from the Year 1-2 time period, to avoid
      the potential effect of the cancer diagnoses from the Year 2 scheduled biopsies on the
      assessments utilized in the "for cause" definitions. Only PSA data from Years 1-2 and
      baseline will be utilized in the computation of the various PSA metrics, and only Central
      Pathology results from Years 1-2 will be utilized to establish post-baseline diagnoses. PSA
      values on or within 42 days after date of biopsy will be excluded from the analyses, to avoid
      potential effects of biopsy on the PSA value.

      For each of the 2 groups of subjects, the following will be summarized: number of subjects
      meeting the corresponding criteria, number and % of subjects diagnosed with prostate cancer,
      number and % of such subjects diagnosed with Gleason 7-10, and number and % of subjects
      diagnosed with either prostate cancer, HGPIN or ASAP. Summaries of the numbers of subjects
      meeting each of the specific criteria for group 1 (a through e) and Group 2 (a through h)
      will be provided.

      In addition, summaries investigating the effect of baseline variables (such as age, family
      history of prostate cancer, prostate volume, percent free PSA, number of cores at the entry
      biopsy) on the occurrence of prostate cancer diagnoses and Gleason 7-10 diagnoses may be
      developed.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        REDUCE trial participants
      
Keywords: prostate cancer; dutasteride; for cause prostate biopsy