Utility of novel biomarkers of ‘cancer therapy-related cardiac dysfunction’ among breast cancer patients
Cancer therapy-related cardiac dysfunction (CTRCD), defined based on changes in left ventricular ejection fraction (LVEF) and cardiac biomarker levels, is a significant complication of chemotherapy, often subclinical in early stages. While conventional markers (high sensitivity cardio troponin I [hscTnI], N-terminal pro-brain natriuretic peptide) are routinely used, the role of novel biomarkers (glycogen phosphorylase BB [GPBB]), myeloperoxidase (MPO), chemokine ligand-23 (CCL23) and macrophage migration inhibitory factor (MIF) remains unknown. Furthermore, the potential influence of shared cancer and cardiovascular disease on tumour marker variability remains unclear, as they share common risk factors and biological pathways. This study aimed to evaluate selected biomarkers alongside hscTnI and LVEF in breast cancer patients undergoing neoadjuvant chemotherapy (NACT). Postmenopausal women ( n = 37) newly diagnosed with locally advanced breast cancer were recruited. Biomarkers were measured using a Beckman Coulter chemiluminescence analyser (Dxi600) and enzyme-linked immunosorbent assay before and after 7 cycles of NACT. The Statistical Package for the Social Sciences software version 20.0 was used for analysing the data. GPBB, hscTnI and cancer antigen 19-9 (CA 19-9) showed a significant increase from baseline after NACT, with a significant reduction in LVEF. No significant differences were observed in CCL23 (Myeloid Progenitor Inhibitor Factor-1), MIF, MPO, CA 125, carcinoembryonic antigen, CA 15-3 and cytokeratin fragment antigen 21-1 before and after NACT. A significant inverse correlation emerged between LVEF and hscTnI levels (r = −0.58, p < 0.001). No significant correlations were seen between LVEF and other biomarkers. Thirty per cent of breast cancer patients developed mild, asymptomatic CTRCD after NACT. The levels of LVEF and hscTnI among patients with and without CTRCD after NACT differed significantly. However, levels of other biomarkers did not differ significantly between the two patient groups. The evaluated novel biomarkers did not demonstrate clinically significant additional utility for assessing cancer therapy-related cardiotoxicity in our cohort. However, these findings are exploratory and require validation in larger studies.