Finasteride and male breast cancer – a register-based nested case-control study in Denmark, Finland, Norway, and Sweden (MK-0906-162)

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Case-control

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  FINASTERIDE
• Medical condition to be studied:
  Breast cancer male

Population studied

• Short description of the study population:
  Males residing in either Denmark, Finland, Norway, or Sweden on the index date who were aged 35 years and older.; In substudy 1: Finasteride user group included men who have redeemed at least two prescriptions of finasteride in the study period (either as one group or divided into three groups, i.e. 2-3 packs of 98 pills, 4-6 packs, and 7+ packs), and Non-finasteride user group included men who have redeemed less than two prescriptions of finasteride in the study period.; In substudy 2: Men with a diagnosis of primary breast cancer (see section 9.2.3 Primary breast cancer case definition) were included as cases, whereas men without a diagnosis of breast cancer at index date were included as controls.
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Special population of interest:
  Other
• Special population of interest, other:
  Breast cancer male patients
• Estimated number of subjects:
  428000

Study design details

• Main study objective:
  1. To describe finasteride users compared to non-users with respect to potential confounding factors.2. To analyze the effect of finasteride use on male breast cancer incidence while takingaccount of confounding factors that may explain the previously reported increasedincidence.
• Outcomes:
  Stage 1 - Person-Years of Exposure to Finasteride by Participant Age and Year Stage 1 - Initial Incidence Rates of Male Breast Cancer Stratified by Exposure to FinasterideStage 1 - All-Cause Mortality Rates in Males with Breast Cancer by Exposure to FinasterideStage 2 - Odds (or Likelihood) of Exposure to Finasteride in Male Breast Cancer Cases Relative to Controls
• Data analysis plan:
  1. Logistic regression will be performed by comparing potential confounding factors forfinasteride users compared to non-users and between levels of cumulative finasteride use. 2. Conditional logistic regression will be performed by comparing male breast cancercases with controls in respect to either finasteride users versus non-users or cumulative finasteride use and including confounding factors in the analysis.