The presence of autoantibodies as a potential prognostic biomarker for breast cancer.

The presence of autoantibodies is closely associated with the occurrence and development of cancer. Autoantibodies can be used as biomarkers for early breast cancer diagnosis. However, the relationship between autoantibodies and the prognosis of breast cancer patients remains elusive. This retrospective study aimed to investigate the correlation between the presence of autoantibodies and outcomes in breast cancer patients. This study included a total of 155 patients from People's Hospital of Henan University (Zhengzhou, China) who were diagnosed with breast cancer from January 2017 to December 2021. The enrolled patients' clinicopathological features were collected, and 88 patients were ultimately involved in the analysis. Univariate and multivariate Cox regression analyses were performed to search for the risk factors related to the poor prognosis of breast cancer patients. The association between the presence of autoantibodies and patients' survival was analysed using Kaplan-Meier curves. After screening, there were 38 autoantibody-positive cases and 50 autoantibody-negative cases. Breast cancer patients with autoantibody-positive had a 57% lower risk of death compared with autoantibody-negative patients. Multivariate Cox regression analysis indicated that the presence of autoantibody could be a potential prognostic predictor for breast cancer, independent of age, histological grade, pathological classification, clinical stage, and the expression levels of hormonal receptors. In addition, autoantibody-positive breast cancer patients had longer progression-free survival and overall survival compared with autoantibody-negative cases. Positive autoantibody was found as an independent biomarker of better prognosis in breast cancer patients, providing a new strategy for the prognostic assessment of breast cancer patients.