Background: The purpose of this study was to develop an in situ immune marker model to predict postoperative oncological outcomes in patients with colorectal cancer (CRC).
Methods: Immunohistochemistry for 13 immune cell markers was performed on tumor tissue microarrays from 300 CRC patients who underwent curative resection from January 2000 to January 2006. Genetic algorithm was applied for the construction of an in situ immune marker model.
Results: The infiltration of CD3+ cells, CD45RO+ cells, and FOXP3+ cells, but not the infiltration of Tryptase+ cells, in the tumor was significantly associated with better clinical outcome in overall survival (OS) and disease-free survival (DFS) of CRC patients, as assessed by univariate analysis (P < 0.05). Based on the genetic algorithms, a total of 6 markers, including CD3, CD45RO, IL17, CD15, Tryptase, and FOXP3, were selected to construct an immune marker model. Our model was identified to have an independent predictive capability for both OS and DFS in Cox multivariable model (P < 0.001). This was further confirmed by the ROC analysis (area under curve: OS, 0.669; DFS, 0.684).
Conclusions: The in situ immune marker model constructed in this study provides a novel approach to identify CRC patients who were at an increased risk for poor oncological outcomes.