Clinical trial NCT01703520: Finasteride (MK-0906) and Male Breast Cancer - A Register-Based Nested Case-Control Study (MK-0906-162/2003.021).
Official title: Finasteride and Male Breast Cancer - A Register-Based Nested Case-Control Study in Denmark, Finland, Norway, and Sweden
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Male Breast Cancer
Keywords: Males breast cancer
Finasteride
PROSCAR®
PROPECIA®
Lead sponsor: Organon and Co
Sponsor class: INDUSTRY
Collaborators: name: Institute for Applied Economics and Health Research Aps
First posted: 2012-10-10
Enrollment: 575216
Sex: MALE
Minimum age (years): 35
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Population-based health and medical registries, prescription registries, and mortality registries in Denmark, Finland, Norway, and Sweden

Brief summary: The objective of this study is to investigate the potential association between finasteride (MK-0906) exposure and the development of breast cancer in men residing in Denmark, Sweden, Finland, and Norway from data in national registries. The primary hypothesis of this study is that the previously reported increased incidence of male breast cancer among finasteride users is explained by confounding factors.


Eligibility criteria: Inclusion Criteria:

* Participant's study medical information available in population-based health and medical registries, prescription registries, and mortality registries in Denmark, Finland, Norway, or Sweden within the observation period of 1995 to 2013
* Male with breast cancer with medical information in one of the 4 country-specific registries in this study OR country- and age-matched control men without breast cancer and with medical information in one of the 4 country-specific registries
* Study participant's exposure to finasteride is available

Exclusion Criteria:

For country- and age-matched control men without breast cancer

* Previous cancer diagnosis or treatment for cancer except non-melanoma skin cancer
* Previous prostatectomy
* Finasteride or dutasteride use (dutasteride is a drug in the same class as finasteride) within first 6 months of registration in the prescription registers (new user design).

Primary outcomes:
measure: Stage 1 - Person-Years of Exposure to Finasteride by Participant Age and Year
timeFrame: Up to 14 years
measure: Stage 1 - Initial Incidence Rates of Male Breast Cancer Stratified by Exposure to Finasteride
timeFrame: Up to 14 years
measure: Stage 1 - All-Cause Mortality Rates in Males with Breast Cancer by Exposure to Finasteride
timeFrame: Up to 14 years
measure: Stage 2 - Odds (or Likelihood) of Exposure to Finasteride in Male Breast Cancer Cases Relative to Controls
timeFrame: Up to 19 years
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: Merck Sharp & Dohme LLC
name: Medical Director
role: STUDY_DIRECTOR
References:
citation: Meijer M, Thygesen LC, Green A, Emneus M, Brasso K, Iversen P, Pukkala E, Bolin K, Stavem K, Ersboll AK. Finasteride treatment and male breast cancer: a register-based cohort study in four Nordic countries. Cancer Med. 2018 Jan;7(1):254-260. doi: 10.1002/cam4.1273. Epub 2017 Dec 13.