Breast cancer remains one of the most significant health risks throughout the world, demanding precise methods for early detection, therapeutic intervention and disease progression monitoring. Despite improving screening and therapy, patient outcomes are highly variable because of complex biology of the disease and therefore validated biological targets and biomarkers are required. Breast cancer heterogeneous disease shaped by genetic, molecular and environmental variables and biomarkers playing a central role in customizing personalized treatment. traditional markers such as hormone receptor (ER, PR) and HER2 status have been applied in clinical decision making but ne research suggests that other molecular signals, circulating tumor cells and microRNAs are promising indicators of tumor behavior and therapeutic response. In this research, tumor tissue and liquid biopsy have been compared using molecular profiling methods and bioinformatics-driven discovery of biomarkers.Immunohistochemistry, PCR-based assays and proteomic techniques have been applied for the identification and validation of novel biomarker panels for specific subtypes of breast cancer. Key findings imply that novel biomarker candidates not only distinguish between aggressive and indolent tumor forms but also predict responsiveness to targeted therapies more accurately over conventional markers. Importantly, integrating these markers in clinical models improved diagnostic specificity and indicated new therapeutic targets for drug development. Identification and validation of new biological targets and biomarkers are the prime innovation of personalized medicine in breast cancer. This research points towards precision oncology's potential to enhance survival and quality of life for patients, offering hope for more effective, individualized treatment regimens in the future.