Vascular Proliferation Index Via a Single-Cell Analysis Is a Superior Prognostic Biomarker to Microvessel Density in Stage II/III Colorectal Cancer

Background/aim Microvessel density (MVD) is an inconsistent prognostic factor in colorectal cancer (CRC). We evaluated the vascular proliferation index (VPI), a qualitative marker of proliferating endothelial cells, as an alternative biomarker. This study aimed to comprehensively compare the prognostic performance of MVD and VPI in Stage II/III CRC patients.Patients and methods MVD and VPI were examined using dual immunohistochemistry (IHC) for CD31/Ki-67 in 85 patients with Stage II/III CRC. Single-cell flow cytometry (FCM) was performed in 72 patients whose samples were suitable for single-cell evaluation among the 85 patients.Results High VPI (>16.5%) via IHC correlated with a significantly shorter disease-free survival (DFS) (p=0.020), whereas MVD showed no prognostic correlation. Consistently, a high Ki-67/CD31 ratio via single-cell FCM predicted a poorer DFS (p=0.002). In the multivariate analysis, high VPI was an independent poor prognostic factor for the DFS (p=0.011). Neither marker was correlated with overall survival.Conclusion VPI via single-cell analysis is a superior, independent prognostic biomarker to MVD for the DFS in Stage II/III CRC, offering an objective platform for postoperative recurrence risk stratification.