The risk of developing prostate cancer in entacapone and levodopa/DDCI users compared to levodopa/DDCI users without entacapone - A nation-wide retrospective register-based study

Study type

• Study topic:
  Human medicinal product

  Disease /health condition
• 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:
  Cohort

  Other
• Non-interventional study design, other:
  Retrospective cohort study

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (N04BA03) levodopa, decarboxylase inhibitor and COMT inhibitor

  levodopa, decarboxylase inhibitor and COMT inhibitor

  (N04BX02) entacapone

  entacapone
• Medical condition to be studied:
  Parkinson's disease

Population studied

• Short description of the study population:
  Population included all males in Finland who have purchased at least one prescription of any Parkinson’s disease medication including entacapone, levodopa/DDCI, monoamine oxidase B (MAO-B) inhibitors, and dopamine agonists (DA) during 1998 – 2009.
• Age groups:
  • Paediatric Population (< 18 years)

    • Adolescents (12 to < 18 years)
  • 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:
  Patients with Parkinson's disease
• Estimated number of subjects:
  16000

Study design details

• Main study objective:
  The primary objective of this study is to compare the incidence rates of developing prostate cancer between group 1 and group 2 where group 1 = treatment with levodopa/DDCI with entacapone +/- DA and/or MAO-B inhibitor, and group 2 = treatment with levodopa /DDCI without entacapone +/- DA and/or MAO-B inhibitor.
• Outcomes:
  Time from the start of follow-up to the first prostate cancer detected. Time from the start of follow-up to death caused by prostate cancer.
• Data analysis plan:
  Comparisons between the treatment groups will be performed by means of hazard ratios (HRs). The HR estimates with 95% CIs will be estimated using the conventional Cox’s proportional hazards model with adjustments for relevant baseline variables and time-dependent variables. The following variables will be considered as potential confounders in these analyses: age group, time since PD diagnosis, PD and BHP treatment history, hospital district, concurrent use of BHP treatments (e.g. finasteride), duration of earlier levodopa/DDCI treatment, and recent changes in PD add-on treatments.