Prognostic importance of CD47 expression on survival of colorectal cancer

Background: The exact value of cluster of differentiation 47 (CD47), known as the “don’t eat me” signal, in colorectal cancer (CRC) has not been clearly revealed. Thus, we investigated the impact of its expression on the overall survival (OS) of CRC patients who underwent colectomy. Methods: Ninety-eight CRC patients were included. The patient population was grouped into two categories based on the median value of CD47 expression examined with immunohistochemistry: negative (< median) and positive (≥ median). The estimation of OS was executed with the Kaplan-Meier method, and the difference in prognostic groups was tested with the log-rank test. The association of CD47 with OS was examined with univariate and multivariate Cox regression models. Results: CD47 expression was recorded in 56.1% of CRC patients. Among the clinicopathological variables, the only significant difference between the prognostic groups was the presence of lymph node involvement (p = 0.005). The OS of patients with CD47 expression was lower than those with no CD47 expression (39.3 months vs. not reached, p = 0.001, respectively). Additionally, in metastatic CRC patients treated with biologic agents, patients with CD47 expression had numerically inferior OS times than those without CD47 expression (37 months vs. 58.5 months, p = 0.05, respectively). Our multivariate analysis showed that CD47 was an independent prognostic factor associated with OS in this cohort (HR: 2.142, p = 0.006). Conclusion: Our study suggests that CD47 may serve as a potential prognostic marker and a promising therapeutic target for anti-CD47–based treatments in CRC.