Ann Rheum Dis: Breast cancer risk and the effects of hormone factors before and after rheumatoid arthritis

The study aims to explore the risk of breast cancer in women with rheumatoid arthritis (RA) and the risk of RA in women with a history of breast cancer, taking into account anti-hormonal therapy for breast canceruse cohort studies and case control designs to identify and analyze new female PATIENTs with RA diagnosed between 2006 and 2016, based on the Swedish National RegisterEach RA patient was matched with five randomly selected subjects from the general population based on age, gender and place of residenceBy linking to registration, the researchers collected information on breast cancer, breast cancer risk factors (reproductive history and hormone replacement therapy) and socio-economic aspectsThe relative risk of breast cancer after RA was assessed using Cox regression and the relative risk of RA was assessed in women with a history of breast cancer using conditional logistic regressionThe risk of breast cancer decreased in women with RA, and the correlation did not decrease after adjusting for breast cancer risk factors (HR -0.80, 95% CI 0.68-0.93)Women with a history of breast cancer also had a correspondingly reduced risk of RA (OR-0.87, 95% CI 0.79-0.95)Compared to women who used other medications, there was no increase draped in women treated with tamoxifen (OR?0.86, 95% CI 0.62-1.20) or aromatase inhibitors (OR?0.97, 95% CI 0.69-1.37)The reduction in breast cancer risk in RA patients pre-diagnosis is long before RA diagnosis; Complementary anti-hormone therapy for breast cancer does not appear to increase the risk of RA