CD47, a transmembrane protein, is widely overexpressed on the tumor cell surface. However, the prognostic significance of CD47 expression in colorectal adenocarcinoma (CRA) has not yet been clarified. Here, we investigated the clinicopathologic significance of CD47 expression in CRA. CD47 expression was evaluated via immunohistochemical analysis of microarray sections of 328 CRA tissues. CD47 expression was observed in 53 (16.2%) of the 328 CRA tissues, and positive expression was associated with lymphatic invasion (p = 0.018), perineural invasion (p = 0.024), tumor budding (p = 0.009), the pathologic N stage (p = 0.022), and the American Joint Committee on Cancer (AJCC) stage (p = 0.027). In survival analyses of 329 patients, a positive CD47 expression was associated with a poor recurrence-free survival (RFS) (p = 0.032). In multivariate analysis, however, it was not an independent prognostic factor. In patients who underwent surgical resection without adjuvant treatment, a positive CD47 expression was associated with a shorter RFS (p = 0.001) but not with cancer-specific survival (CSS). In patients who received postoperative adjuvant treatment, no significant differences were found in both RFS and CSS. In conclusion, we investigated CD47 expression in 328 CRA tissues. A positive CD47 expression was observed in a minority (16.2%) of the tissues and was significantly associated with adverse clinicopathologic features and a poor patient outcome.
Keywords: CD47; colorectal adenocarcinoma; immune checkpoints; immunohistochemistry; prognosis.