Abstract
In women, breast cancer (BC) is the most frequently cancer and among the leading causes of cancer-related death. Breast cancer is heterogeneous tumors group with varied molecular and morphological subtypes, making disease detection and patient outcomes evolution difficult. So, biomarkers are required to aim pathologists choose and apply the best therapy for each patient. For the last decades, reports have increasingly regarding biomarkers in liquid body fluids. Blood proteins, circulating components or secreted by cancers, are attributed to several biological functions and are an important tumor biomarkers source. These blood proteins (extracted from plasma or serum) can be used for minimally invasive, easy, simple and inexpensive determination of cancer risk, disease progression, prognostication and monitoring, treatment adjusting and early diagnosis. In this review, we discussed the main established studies on blood proteins in breast cancer and evaluate the potential of blood proteins to be prognostic and/or predictive breast cancer biomarkers.