Identification of a novel circulating proteoglycan as a diagnostic and prognostic biomarker for colon hyperproliferative disorders

Introduction Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality. Although screening methods such as faecal occult blood testing combined with polypectomy can reduce incidence by up to 80%, their sensitivity remains limited. Therefore, there is a pressing need to identify novel biomarkers to improve the diagnosis and prognosis of CRC. Materials and Methods Samples from 210 CRC patients, 34 with adenomas/polyps, and 57 healthy volunteers were analysed, divided into two independent cohorts. Plasma Ca10 levels were quantified using ELISA. ROC curves and AUC values were employed to compare Ca10 levels between groups. Additionally, the relationship between Ca10 and clinical stage, vital status (survivor or deceased), and overall survival was evaluated. Patients were stratified into Ca10-high and Ca10-low groups using the Youden index. Results Plasma Ca10 levels were significantly elevated in CRC patients compared to healthy volunteers, and even higher in those with polyps, with AUCs of 0._ and 0._ in both cohorts (exact values to be inserted). Ca10 levels inversely correlated with disease stage and were higher in survivors than in deceased patients. Notably, patients classified as Ca10-low according to the Youden index showed improved survival. Thus, circulating Ca10 levels predicted CRC outcomes in both cohorts. Conclusions The proteoglycan Ca10 emerges as a novel circulating biomarker for colorectal tumours, demonstrating diagnostic and prognostic potential across two independent patient cohorts.