The prognosis of breast cancer is strongly influenced by the stage of the disease; therefore, it is essential that breast cancer lesions be diagnosed at the earliest stages. There is an urgent need to identify different biomarkers with a high accuracy for the early detection of this cancer to facilitate clinical management of the disease. A wide number of substances named serum tumor markers can be detected in the serum of patients with breast cancer, including tumor-associated proteins, cytokines, stimulating or inhibiting factors, autoantibodies to antigen tumor-associated substances and miRNAs. Despite ASCO and NACB recommendations, the routine use of breast cancer tumor markers by a significant proportion of oncologists is common, particularly after primary treatment of early tumors. The new promising circulating markers are HER2/neu, Trx 1, CSF1, autoantibodies against these tumor-associated antigens, and miRNAs, which are non-coding RNA molecules that regulate the translation of mRNA and control a number of biological processes, including oncogenic cells proliferation. The expression of single miRNA results in a miRNA signature, and is considered a potential biomarker for early breast cancer. However, additional studies are needed to identify its real usefulness.
Keywords: Early breast cancer, biomarker, serum tumor markers, ELISA, HER2, Trx1, CSF1, MicroRNA.