Evaluation of immunohistochemical expression of survivin and its correlation with -31G/C gene polymorphism in colorectal cancer.

Colorectal cancer (CRC) placed among the most common neoplasm. Survivin is a member of the inhibitor apoptosis gene family. This gene could be associated with aggressive behavior in numerous types of cancers. The aim of the present study was to evaluate the immunohistochemical expression of survivin gene and its correlation with -31G/C polymorphism in CRC patients. This case-control study was performed on 90 cases: 30 adenocarcinoma, 30 adenomatous polyp, and 30 normal colon. Immunohistochemical expression of survivin evaluated on formalin-fixed paraffin-embedded tissue and -31G/C polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. Results showed that the subjects carrying C/C genotype with 43.3% (p = 0.002' OR = 12.188, CI = 2.530-58.720) and G/C genotype with 43.3% (p = 0.032' OR = 4.432, CI = 1.133-17.341) significantly had increased risk of CRC compared with subjects carrying GG genotype. Allelic frequencies showed statistically significant difference (p = 0.001) among adenocarcinoma (G = 35%, C = 65%), adenomatous (G = 43.3, C = 56.7), and normal group (G = 68.3, C = 31.7). Immunohistological evaluation showed nuclear survivin protein expression in patients with the CC genotype higher than in patient with the GG and GC genotypes (p = 0.002). The results suggest that C allele of - 31G/C polymorphism in survivin might be cooperative in CRC development.