Central Illustration : New Cardiovascular Biomarkers in Breast Cancer Patients Undergoing Doxorubicin-Based Chemotherapy. Cardiovascular diseases (CVDs) are relevant to the management of breast cancer treatment since a substantial number of patients develop these complications after chemotherapy. This study aims to evaluate new cardiovascular biomarkers, namely CXCL-16 (C-X-C motif ligand 16), FABP3 (fatty acid binding protein 3), FABP4 (fatty acid binding protein 4), LIGHT (tumor necrosis factor superfamily member 14/TNFS14), GDF-15 (Growth/differentiation factor 15), sCD4 (soluble form of CD14), and ucMGP (uncarboxylated Matrix Gla-Protein) in breast cancer patients treated with doxorubicin (DOXO). This case-control study was conducted in an oncology clinic that included 34 women diagnosed with breast cancer and chemotherapy with DOXO and 34 control women without cancer and CVD. The markers were determined immediately after the last cycle of chemotherapy. The statistical significance level adopted was 5%. The breast cancer group presented higher levels of GDF-15 (p<0.001), while control subjects had higher levels of FABP3 (p=0.038), FABP4 (p=0003), sCD14, and ucMGP (p<0.001 for both). Positive correlations were observed between FABPs and BMI in the cancer group. GDF15 is an emerging biomarker with potential clinical applicability in this scenario. FABPs are proteins related to adiposity, which are potentially involved in breast cancer biology. sCD14 and ucMGP engage in inflammatory and vascular calcification. The evaluation of these novel cardiovascular biomarkers could be useful in the management of breast cancer chemotherapy with DOXO.