Abstract
BACKGROUND: Secreted Frizzled-Related Protein 5 (SFRP5) modulates Wnt signalling pathways, affecting diverse biological processes. We assessed the diagnostic and prognostic value of circulating SFRP5 (cSFRP5) in colorectal cancer (CRC) METHODS: Plasma cSFRP5 concentrations were measured using enzyme-linked immunosorbent assay (ELISA) in healthy donors (n = 133), individuals diagnosed with CRC (n = 449), colorectal polyps (n = 85), and medical conditions in other organs including cancer, inflammation, and benign states (n = 64). RESULTS: Patients with CRC, polyps, and other conditions showed higher cSFRP5 levels than healthy individuals (p < 0.0001). Receiver operating characteristic curves comparing healthy donors with medical conditions, polyps and CRC were 0.814 (p < 0.0001), 0.763 (p < 0.0001) and 0.762 (p < 0.0001), respectively. In CRC, cSFRP5 correlated with patient age (p < 0.0001), tumour stage (p < 0.0001), and histological differentiation (p = 0.0273). Levels, adjusted for patient age, sex, plasma age and collection institution, peaked in stage II versus I (p < 0.0001), III (p = 0.0002) and IV (p < 0.0001), were lowest in stage I versus III (p = 0.0002) and IV (p = 0.0413), with no difference between stage III and IV. Elevated cSFRP5 levels predicted longer overall survival in stages II-III CRC (univariate: HR 1.82, 95% CI: 1.02-3.26, p = 0.024; multivariable: HR 2.34, 95% CI: 1.12-4.88, p = 0.015). CONCLUSION: This study confirms cSFRP5 levels are elevated in CRC compared to healthy control and reveals a correlation between elevated cSFRP5 and overall survival in stages II-III disease.