(33) Antiplatelet Drugs and Breast Cancer Risk in a Large Nationwide Danish Case-Control Study

Sunday, August 28, 2022

8:00 AM – 1:45 PM CEST

Location: Hall C

Publication Number: 1078

Presenting Author(s)

Manon Cairat
– International agency for research on cancer, paris, France

Co-Author(s)

Anton Pottegård, PhD, MSc
– University of Southern Denmark, Odense C, Denmark
Morten Olesen
– Clinical Pharmacology, Pharmacy and Environmental Medicine, Department of Public Health, University of Southern Denmark, Denmark, Denmark
Laure Dossus
– International Agency for Research on Cancer, Lyon, France, France
Agnès Fournier
– Paris-Saclay University, UVSQ, Inserm, Gustave Roussy, "Exposome and Heredity" team, CESP, F-94805, Villejuif, France, Villejuif, Ile-de-France, France
Blánaid Hicks
– Lecturer, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom

Background: Low-dose aspirin has been hypothesized to prevent cancer risk by inhibiting platelet aggregation. However, the anti-cancer effect of low-dose aspirin has recently been questioned and its effect on breast cancer development remains unclear. The impact of other antiplatelet drugs on breast cancer risk has rarely been evaluated.

Objectives: Thus this study aimed to investigate the associations between breast cancer risk and antiplatelet drug use in a nationwide nested case-control study.

Methods: From the Danish healthcare registries we identified as cases all women with invasive breast cancer diagnosis between 2001 and 2018 (n=68,852). We matched each case to 10 population controls on age and calendar time. We used the prescription registry to identify exposure to low-dose aspirin, clopidogrel and dipyridamole. We defined ever use of antiplatelet drugs as at least 2 prescriptions filled up to one year before the index date. We applied conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for breast cancer associated with the use of antiplatelet drugs, overall, by breast cancer subtype and by cumulative dose.

Results: Twelve percent of women had ever been exposed to low-dose aspirin, 2% to clopidogrel and 2% to dipyridamole. In multivariable models, breast cancer risk was not associated with ever use of low-dose aspirin [OR= 1.00 (0.97 – 1.03)], clopidogrel [OR= 0.93 (0.86 – 1.00)], and dipyridamole [OR= 1.01 (0.94 – 1.10)], compared with never use, and there was no evidence of a dose-response relation. However, we found an inverse association between dipyridamole use and breast cancer risk among women aged less than 55 years old, with suggestion of a dose-response relationship [OR per 1000 Defined Daily Doses=0.71 (0.53 – 0.95)]. Associations did not differ by breast cancer histological type, estrogen receptor status or clinical stage at diagnosis.

Conclusions: Overall, the findings from this study do not support the use of antiplatelet drugs for breast cancer prevention.