The estimated new cases of breast cancer (BC) patients were 2.26 million in 2020, which accounted for 11.7% of all cancer patients, making it the most prevalent cancer worldwide. Early detection, diagnosis and treatment are crucial to reduce the mortality, and improve the prognosis of BC patients. Despite the widespread use of mammography screening as a tool for BC screening, the false positive, radiation, and overdiagnosis are still pressing issues that need to be addressed. Therefore, it is urgent to develop accessible, stable, and reliable biomarkers for non-invasive screening and diagnosis of BC. Recent studies indicated that the circulating tumor cell DNA (ctDNA), carcinoembryonic antigen (CEA), carbohydrate antigen 15-3 (CA15-3), extracellular vesicles (EV), circulating miRNAs and BRCA gene from blood, and the phospholipid, miRNAs, hypnone and hexadecane from urine, nipple aspirate fluid (NAF) and volatile organic compounds (VOCs) in exhaled gas were closely related to the early screening and diagnosis of BC. This review summarizes the advances of the above biomarkers in the early screening and diagnosis of BC.
Keywords: biomarkers; breast cancer; diagnosis; early screening; noninvasiveness.