Laboratory Testing in Breast Cancer: Transforming Early Detection and Prognosis

Abstract

Breast cancer is the most common cancer globally, with an estimated 2.26 million new cases in 2020. Early detection significantly improves prognosis, but current imaging techniques have limitations. Molecular biomarkers have emerged as valuable tools for enhancing diagnosis, prognosis, and treatment strategies. Established biomarkers such as estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 are routinely used for breast cancer subtyping and guiding therapy decisions. However, there is a need for more specific and personalized biomarkers, particularly for aggressive subtypes like triple-negative breast cancer. Novel biomarkers under investigation include death-associated protein kinase 1 (DPK1), carnitine palmitoyltransferase-1A (CPT-1A), tumor immune microenvironment markers, and methylated gene panels. Understanding signaling pathways like PI3K/AKT/mTOR and NF-κB also provides opportunities for identifying therapeutic targets and biomarkers. The clinical implementation of biomarkers involves a rigorous multi-phase process, from discovery to validation and clinical utility assessment. Emerging biomarkers such as long non-coding RNAs and circulating tumor DNA show promise for non-invasive monitoring of tumor dynamics. Collaboration between pathologists and physicians, along with evidence-based implementation in clinical trials, is crucial for advancing personalized medicine in breast cancer management. Continued research and integration of laboratory testing innovations will be essential for improving early detection, precise diagnosis, and targeted treatment of breast cancer.