CD31 Positivity and Prediction of Tumor Invasive Behavior in Colorectal Cancer

Background: Due to the close association of CD31 marker positivity and tumor microvessel density, the relationship between this marker and the pathophysiological behavior of the tumor, such as the ability to invade the surrounding tissues and organ damage, is also quite probable. Objectives: We aimed at evaluating the association of CD31 expression with the likelihood of microvascular invasion and other abnormal histopathological findings in patients with colorectal cancer. Methods: In our cross-sectional study, the pathology numbers of 50 samples that were diagnosed with colorectal cancer in their pathology report during 2021 and 2022 were identified by searching our hospital information system. Immunohistochemical staining (IHC) using CD31 monoclonal antibody was performed for assessing CD31 positivity. Results: CD31 positivity was found in 34.0% of cases, 35.5% in colon masses, and 31.6% in rectal masses. The patients with positive CD31 had significantly higher tumor grades (P < 0.045). The prevalence rate of vascular invasion was significantly higher in patients with positive CD31 compared to those with negative CD31 states (47.1% versus 12.1%, P = 0.006). Also, the rate of lymph node involvement in the groups with positive and negative CD31 was 58.8% and 24.2%, respectively, indicating a significant difference (P = 0.016). In multivariable logistic regression models, CD31 positivity was shown to be associated with the risk for vascular invasion (OR = 6.211, P = 0.020) and lymph node involvement (OR = 6.535, P = 0.011). Conclusions: CD31 positivity in patients with colorectal cancer can effectively predict invasive behavior of the tumor including vascular invasion, lymph node involvement, and high tumor grades.