Finasteride use and risk of male breast cancer: a case-control study using individual-level registry data from Denmark, Finland, and Sweden

Thora Majlund Kjærulff*, Annette Kjær Ersbøll, Anders Green, Martha Emneus, Klaus Brasso, Peter Iversen, Eero Pukkala, Kristian Bolin, Lau Caspar Thygesen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Background: In case reports, concerns have been raised as to whether finasteride use increases the risk of Male breast cancer. Previous epidemiologic evidence on the potential link is conflicting. This study aimed to assess whether an association between finasteride use and Male breast cancer exists after accounting for potential confounders. Methods: The source population consisted of all men (35 years) from Denmark (1995–2014), Finland (1997–2013), and Sweden (2005–2014). Cases with incident Male breast cancer were identified in the cancer registries and matched with 50 density-sampled, age, and country-matched Male population controls per case. Exposure information on finasteride use was derived from the prescription registries. Potential confounders were identified using the directed acyclic graph methodology and measured by use of information from nation-wide registries. Results: The study population comprised 1,005 Male breast cancer cases and 43,058 controls. Confounder-adjusted odds of finasteride exposure were not statistically significantly increased [OR, 1.09; 95% confidence interval (CI), 0.77–1.54] in breast cancer cases relative to controls. There was no evidence of a dose–response relationship, as the group with greatest exposure to finasteride was associated with lowest OR of Male breast cancer [OR, 0.72 (95% CI, 0.40–1.30)]. Sensitivity analyses did not reveal marked changes in results with different exposure definitions or for specific subgroups. Conclusions: Results from this study provided no evidence that finasteride use was associated with Male breast cancer. Impact: This large confounder-adjusted study supports the view that exposure to finasteride is not associated materially with Male breast cancer risk.

Original languageEnglish
JournalCancer Epidemiology, Biomarkers & Prevention
Volume28
Issue number5
Pages (from-to)980-986
ISSN1055-9965
DOIs
Publication statusPublished - May 2019

Fingerprint

Male Breast Neoplasms
Finasteride
Denmark
Finland
Registries
Case-Control Studies
Confidence Intervals
Population Control
Population
Prescriptions

Cite this

@article{c007f84424484c059af7e04310c82005,
title = "Finasteride use and risk of male breast cancer: a case-control study using individual-level registry data from Denmark, Finland, and Sweden",
abstract = "Background: In case reports, concerns have been raised as to whether finasteride use increases the risk of Male breast cancer. Previous epidemiologic evidence on the potential link is conflicting. This study aimed to assess whether an association between finasteride use and Male breast cancer exists after accounting for potential confounders. Methods: The source population consisted of all men (35 years) from Denmark (1995–2014), Finland (1997–2013), and Sweden (2005–2014). Cases with incident Male breast cancer were identified in the cancer registries and matched with 50 density-sampled, age, and country-matched Male population controls per case. Exposure information on finasteride use was derived from the prescription registries. Potential confounders were identified using the directed acyclic graph methodology and measured by use of information from nation-wide registries. Results: The study population comprised 1,005 Male breast cancer cases and 43,058 controls. Confounder-adjusted odds of finasteride exposure were not statistically significantly increased [OR, 1.09; 95{\%} confidence interval (CI), 0.77–1.54] in breast cancer cases relative to controls. There was no evidence of a dose–response relationship, as the group with greatest exposure to finasteride was associated with lowest OR of Male breast cancer [OR, 0.72 (95{\%} CI, 0.40–1.30)]. Sensitivity analyses did not reveal marked changes in results with different exposure definitions or for specific subgroups. Conclusions: Results from this study provided no evidence that finasteride use was associated with Male breast cancer. Impact: This large confounder-adjusted study supports the view that exposure to finasteride is not associated materially with Male breast cancer risk.",
author = "Kj{\ae}rulff, {Thora Majlund} and Ersb{\o}ll, {Annette Kj{\ae}r} and Anders Green and Martha Emneus and Klaus Brasso and Peter Iversen and Eero Pukkala and Kristian Bolin and Thygesen, {Lau Caspar}",
note = "Copyright {\circledC}2019, American Association for Cancer Research.",
year = "2019",
month = "5",
doi = "10.1158/1055-9965.EPI-18-0904",
language = "English",
volume = "28",
pages = "980--986",
journal = "Cancer Epidemiology, Biomarkers & Prevention",
issn = "1055-9965",
publisher = "American Association for Cancer Research (A A C R)",
number = "5",

}

Finasteride use and risk of male breast cancer : a case-control study using individual-level registry data from Denmark, Finland, and Sweden. / Kjærulff, Thora Majlund; Ersbøll, Annette Kjær; Green, Anders; Emneus, Martha; Brasso, Klaus; Iversen, Peter; Pukkala, Eero; Bolin, Kristian; Thygesen, Lau Caspar.

In: Cancer Epidemiology, Biomarkers & Prevention, Vol. 28, No. 5, 05.2019, p. 980-986.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Finasteride use and risk of male breast cancer

T2 - a case-control study using individual-level registry data from Denmark, Finland, and Sweden

AU - Kjærulff, Thora Majlund

AU - Ersbøll, Annette Kjær

AU - Green, Anders

AU - Emneus, Martha

AU - Brasso, Klaus

AU - Iversen, Peter

AU - Pukkala, Eero

AU - Bolin, Kristian

AU - Thygesen, Lau Caspar

N1 - Copyright ©2019, American Association for Cancer Research.

PY - 2019/5

Y1 - 2019/5

N2 - Background: In case reports, concerns have been raised as to whether finasteride use increases the risk of Male breast cancer. Previous epidemiologic evidence on the potential link is conflicting. This study aimed to assess whether an association between finasteride use and Male breast cancer exists after accounting for potential confounders. Methods: The source population consisted of all men (35 years) from Denmark (1995–2014), Finland (1997–2013), and Sweden (2005–2014). Cases with incident Male breast cancer were identified in the cancer registries and matched with 50 density-sampled, age, and country-matched Male population controls per case. Exposure information on finasteride use was derived from the prescription registries. Potential confounders were identified using the directed acyclic graph methodology and measured by use of information from nation-wide registries. Results: The study population comprised 1,005 Male breast cancer cases and 43,058 controls. Confounder-adjusted odds of finasteride exposure were not statistically significantly increased [OR, 1.09; 95% confidence interval (CI), 0.77–1.54] in breast cancer cases relative to controls. There was no evidence of a dose–response relationship, as the group with greatest exposure to finasteride was associated with lowest OR of Male breast cancer [OR, 0.72 (95% CI, 0.40–1.30)]. Sensitivity analyses did not reveal marked changes in results with different exposure definitions or for specific subgroups. Conclusions: Results from this study provided no evidence that finasteride use was associated with Male breast cancer. Impact: This large confounder-adjusted study supports the view that exposure to finasteride is not associated materially with Male breast cancer risk.

AB - Background: In case reports, concerns have been raised as to whether finasteride use increases the risk of Male breast cancer. Previous epidemiologic evidence on the potential link is conflicting. This study aimed to assess whether an association between finasteride use and Male breast cancer exists after accounting for potential confounders. Methods: The source population consisted of all men (35 years) from Denmark (1995–2014), Finland (1997–2013), and Sweden (2005–2014). Cases with incident Male breast cancer were identified in the cancer registries and matched with 50 density-sampled, age, and country-matched Male population controls per case. Exposure information on finasteride use was derived from the prescription registries. Potential confounders were identified using the directed acyclic graph methodology and measured by use of information from nation-wide registries. Results: The study population comprised 1,005 Male breast cancer cases and 43,058 controls. Confounder-adjusted odds of finasteride exposure were not statistically significantly increased [OR, 1.09; 95% confidence interval (CI), 0.77–1.54] in breast cancer cases relative to controls. There was no evidence of a dose–response relationship, as the group with greatest exposure to finasteride was associated with lowest OR of Male breast cancer [OR, 0.72 (95% CI, 0.40–1.30)]. Sensitivity analyses did not reveal marked changes in results with different exposure definitions or for specific subgroups. Conclusions: Results from this study provided no evidence that finasteride use was associated with Male breast cancer. Impact: This large confounder-adjusted study supports the view that exposure to finasteride is not associated materially with Male breast cancer risk.

U2 - 10.1158/1055-9965.EPI-18-0904

DO - 10.1158/1055-9965.EPI-18-0904

M3 - Journal article

C2 - 30842126

VL - 28

SP - 980

EP - 986

JO - Cancer Epidemiology, Biomarkers & Prevention

JF - Cancer Epidemiology, Biomarkers & Prevention

SN - 1055-9965

IS - 5

ER -