SOX17 expression in tumor endothelial cells in colorectal cancer and its association with favorable outcomes in patients

The high mortality rate of colorectal cancer (CRC) highlights the need for new treatment strategies; however, the venous invasion mechanisms in tumor endothelial cells within CRC remain unexplored. Therefore, we investigated the clinicopathological features of SRY-box transcription factor 17 (SOX17) in CRC. Immunohistochemical staining was performed on 55 CRC tissue specimens using a SOX17-specific antibody, followed by Kaplan-Meier and Cox proportional hazards regression analyses. SOX17 immunoreactivity was detected in the endothelial cells of tumor-penetrating vessels in 35/55 CRC samples. Kaplan-Meier analysis indicated that patients with SOX17 immunoreactivity had favorable overall and progression-free survival (log-rank test, P = 0.03 and 0.02, respectively). Notably, tumor endothelial SOX17 immunoreactivity was associated with a favorable prognosis in patients with stage III or IV disease (OS, P = 0.0089; PFS, P = 0.0065). Cox proportional hazard regression analysis indicated that SOX17 immunoreactivity is an independent factor for predicting favorable overall and progression-free survival in CRC (P = 0.02 and 0.01, respectively). The present findings suggest that SOX17 expression in tumor endothelial cells is a potential indicator of favorable prognosis in patients with CRC.