Statins and Breast Cancer Recurrence: A Danish Nationwide Cohort Study with up to 23 Years of Follow-up

Saturday, August 27, 2022

1:30 PM – 1:45 PM CEST

Location: Congress Hall D5

Publication Number: 165

Background: Statins prevent the synthesis of cholesterol and isoprenoids, which may influence tumor initiation, growth and metastases. Statin use has been associated with a reduced rate of breast cancer recurrence < 10 years after primary diagnosis.

Objectives: We investigated the association between post-diagnosis statin use and recurrence up to 23 years after primary breast cancer diagnosis.

Methods: We included all women diagnosed with an early breast cancer during 1996-2004 registered in the Danish Breast Cancer Group database. We obtained information on statin exposure (≥1 prescriptions) from the Danish National Prescription Registry. We modelled statin use as a time-varying exposure lagged by one year. We started follow-up at breast cancer diagnosis and followed patients until the first recurrence, death, second cancer, or end of 2018. We used Cox regression analysis to estimate 5-, 10-, 15-, 20-year crude and adjusted hazard ratios (HRs), with 95% confidence intervals (CI), for breast cancer recurrence among statin users compared with nonusers, and with censoring for competing risks. We also conducted landmark sensitivity analyses starting at year 5 and year 10 after primary diagnosis.

Results: We included 21,684 women diagnosed with breast cancer. During 242,427 person-years of follow-up, 4,902 patients experienced breast cancer recurrence. We found slightly reduced 5- and 10- year hazards of recurrence among statin users compared with nonusers (5-year adjusted HR= 0.84, 95% CI= 0.67-1.04; 10-year adjusted HR=0.89, 95% CI=0.77-1.04). The 15- and 20-year HRs were close to unity (20-year adjusted HR=0.94, 95% CI=0.85-1.04). Our landmark analyses showed no association between statin use and breast cancer recurrence (5-year landmark cohort: adjusted HR=1.00, 95%CI=0.86-1.16; 10-year landmark cohort: adjusted HR=1.05, 95%CI=0.91-1.20).

Conclusions: Our findings do not support a long-term anti-recurrence effect of statins in breast cancer survivors

Presenting Author(s)

Elisabeth Solmunde, BSc

Medical student
Department of Clinicial Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
Aarhus N, Midtjylland, Denmark

Slides

Co-Author(s)

Rikke N Pedersen

Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
Aarhus N, Midtjylland, Denmark
LM

Lene Mellemkjær

Danish Cancer Society Research Center, Copenhagen, Denmark, Denmark
SF

Søren Friis

Danish Cancer Society, Denmark
BE

Bent Ejlertsen

Department of Oncology, Rigshospitalet, Copenhagen University, Copenhagen, Denmark, Denmark
TA

Thomas P. Ahern

Department of Surgery and Biochemistry, Larner College of Medicine, University of Vermont, Burlington, VT, USA, United States
Mette Norgaard, MD, PhD

Professor, MD, PhD
Department of Clinical Epidemiology, Aarhus University
Aarhus N, Midtjylland, Denmark
DC

Deirdre Cronin-Fenton

Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark, Denmark