Project title: Association between antidepressant use and second breast cancer event after ductal carcinoma in situ diagnosis; a nested case-control study.
Completed in: 2021 | Faculty advisor: Clement Furlong
Controversy exists regarding the potential relationship between antidepressant use and risk of breast cancer. No previous studies have evaluated the relationship between antidepressant use and risk of a subsequent breast cancer among women with a history of ductal carcinoma in situ (DCIS). Using a nested case-control study design, we compared 338 cases of women diagnosed with DCIS and a subsequent breast cancer and 599 individually matched controls (on age, year of DCIS diagnosis, primary treatment, histology, grade, and disease-free survival time) who were diagnosed with DCIS but not a subsequent breast cancer. Information on antidepressant use after DCIS diagnosis was obtained from medical records. Antidepressant use after initial DCIS was not associated with risk of a subsequent breast cancer event (OR = 1.17, 95% CI: 0.84, 1.61). However, stratified analysis showed an increased risk among women without a first-degree family history of breast cancer (OR = 1.76, 95% CI: 1.11, 2.79). Similar results were seen when antidepressants were analyzed by drug class. Antidepressant use may be associated with an increased risk of a subsequent breast cancer event among women with a history of DCIS who do not have a first-degree history of breast cancer. This is the first study to evaluate the relationship between antidepressant use and risk of a subsequent breast cancer event among women with DCIS. Further studies are needed to confirm the associations observed.