Tissue microarray-determined expression profiles of SLIT2 in colorectal adenocarcinoma: Association with clinicopathological parameters

Accumulated evidence has revealed that increased SLIT2 expression is involved in several cancers, including hepatocellular carcinoma, recurrence of endometrioid adenocarcinoma, and prostate cancer. This study evaluated SLIT2 expression in colorectal cancers using tissue microarray analysis, and determined its association with clinicopathological stage. Immunohistochemical analysis of SLIT2 was performed in 194 specimens, including 181 primary colorectal adenocarcinomas (37 well differentiated, 103 moderately differentiated, and 41 poorly differentiated), and 13 samples of normal colonic epithelium. All colorectal adenocarcinomas showed significant immunohistochemical expression of SLIT2 when compared with normal colon epithelium. In multivariate analysis, the SLIT2 immunostaining score was significantly correlated with tumor differentiation and M stage, but not with T stage (P = 0.986), N stage (P = 0.840), and overall AJCC stage (P = 0.171). Furthermore, using SLIT2 scores as variable parameters, higher scores (≥ 300) were associated with higher mortality, and reach statistical significance (P = 0.043). Therefore, the development of pharmacological agents targeting the SLIT2 pathway may prolong survival and slow tumor progression in patients with colorectal adenocarcinoma.