Breast manifestations and breast cancer risk in a cohort of female Egyptian systemic lupus erythematosus patients

Abstract Background Breast involvement in Systemic Lupus Erythematosus (SLE) has been previously described in the literature. Diagnosing lupus-related mastitis is challenging for both patients and clinicians, as it is essential to rule out more serious conditions such as breast cancer. Unfortunately, there are no established guidelines or distinctive features that clearly define breast involvement in SLE that complicates both diagnosis and management. This study aims to evaluate breast manifestations, sono-mammographic findings, and breast cancer risk in SLE patients. Methodology A case-control study was conducted including 100 female SLE patients (aged > 30 years, diagnosed by 2012 SLICC criteria) and 100 age-matched healthy controls. All participants underwent clinical breast evaluation, laboratory investigations, breast cancer risk assessment using the Gail Model, and breast imaging (mammography and ultrasound), with findings classified according to the BIRADS system. Disease activity was assessed by Systemic Lupus Erythematosus Disease Activity Index-2 K(SLEDAI2k). Results Breast manifestations were reported by 12% of patients, most frequently as breast lumps (8%) and pain (6%). Sono-mammographic abnormalities were detected in 28% of patients, with fibroadenoma (10%) and fibrocystic changes (8%) being the most common findings. Lupus mastitis was identified in 5% of patients, all with severe SLE activity; most had subcutaneous edema, and some showed calcifications or fibroadenoma. Pathological confirmation was obtained in two cases. According to the Gail model, 98% of SLE patients had an average 5-year breast cancer risk, all lupus mastitis cases had average risk. Compared to healthy controls, there was no significant difference in sono-mammographic findings, but controls had a higher proportion with above-average breast cancer risk. No significant demographic or laboratory differences were found between SLE patients with and without breast manifestations, except for a higher rate of severe disease activity among those with breast manifestations. Conclusions Breast involvement in SLE, though rare, presents significant diagnostic challenges. Lupus mastitis should be considered in patients with breast lumps, longstanding disease and high disease activity. Regular breast monitoring and multidisciplinary evaluation are essential to avoid misdiagnosis and ensure appropriate management.