Аннотация
Background/Objectives: Chemotherapy-induced cardiotoxicity is a serious complication in breast cancer treatment, particularly with anthracyclines and HER2-targeted therapy. To evaluate the association between early elevations of cardiac markers (troponin and NT-proBNP) and the development of chemotherapy-induced cardiotoxicity in adult patients with breast cancer. Methods: This systematic review and meta-analysis were conducted according to PRISMA guidelines and registered with PROSPERO (CRD420261301170). A systematic search of PubMed/MEDLINE, Cochrane CENTRAL, and Web of Science databases was conducted. Studies evaluating cardiac markers in breast cancer patients receiving chemotherapy were included in the review. Results: Fourteen studies were included in the qualitative synthesis. Five studies were included in the meta-analysis. Elevated troponin levels were associated with higher odds of subsequent cardiac dysfunction; however, the pooled association was not statistically significant [OR = 3.40, 95% CI 0.69–16.67, p = 0.13] and showed substantial heterogeneity [I2 = 86.97%]. A leave-one-out sensitivity analysis was used to identify a study that exerted a substantial influence; its exclusion eliminated between-group heterogeneity and attenuated the pooled effect estimate. Conclusions: Early troponin elevation may provide a biological signal of myocardial injury during cancer therapy. However, the association between elevated troponin level and cancer therapy-related cardiac dysfunction did not reach the threshold of statistical significance and showed substantial heterogeneity. Troponin and NT-proBNP may provide complementary information to cardiac imaging, but their predictive performance and clinical utility require further prospective validation.