Prognosticating 2-Year Survival Rate of Breast Cancer Patients Through Plasma miRNA-21 and Other Associating Factors

Background: miRNA-21, one of breast cancer (BC) predictive markers, is now gaining cardinal attention from researchers worldwide to evaluate BC patients' survival rate. However, cancer staging, hormonal status, and other BC markers still have to be discussed. We aim to determine the relationship between miRNA-21 and associating factors such as BC staging, other tumor markers, and hormonal status to predict the 2-year survival rate of BC patients. Methods: We conducted a prospective cohort study on 49 BC patients (26 early stage, 23 advanced stage). Apart from cancer staging, we also examined CEA, Ca15-3, and hormonal status (ER, PR, Her2) and correlated them with miRNA-21 to predict 2-year survival rate. We did bivariate, multivariate, and survival analyses to determine the link between miRNA-21 and those factors to prognosticate on 2-year survival rate. Results: There are significances between advanced and loco-regional stage (p < 0.001); high and low miRNA-21 (p = 0.002) and CA 15-3 (p = 0.001), and low survival rate in patients with ER/PR-Her2-status (p=0.0015). Cox proportional hazard showed miRNA-21 (Adjusted HR 1.41; 95% CI = 1.205-1.632), cancer stage (Adjusted HR 9.5; 95% CI = 1.378-20.683), and CA15-3 (Adjusted HR 4.64; 95% CI = 1.548-13.931) affected patients' mortality within 2 years. Conclusion: Low two-year survival rate depends on miRNA-21, cancer stage, CA15-3, and ER/PR-Her2-. Cancer stage is robustly associated with miRNA-21 in predicting 2-year survival rate.