Overexpression of Rad51 Predicts Poor Prognosis in Colorectal Cancer: Our Experience with 54 Patients.

Abstract

BACKGROUND:Aberrant Rad51 expression is implicated in the progression of human malignancies. However, the role of Rad51 in colorectal cancer (CRC) remains undefined. This study aimed to establish a relationship between Rad51 and clinicopathologic features of CRC. METHODS:We retrospectively examined the paraffin-embedded tissue samples obtained from 54 patients with CRC who had received surgical therapies at our institution during 2006-2008. Rad51 expression in adenocarcinoma, paracancerous tissue, and normal colonic tissue was determined by immunohistochemistry. The correlation between Rad51 immunoreactivity and clinicopathologic features of these patients was evaluated. RESULTS:Rad51 immunoreactivity was detected in 67% of adenocarcinoma, 48% of paracancerous tissue, and 27% of normal colonic mucosa. Rad51 expression in adenocarcinoma was significantly higher than normal colonic tissue (p < 0.05). Rad51 was also overexpressed in poorly differentiated tumors and tumor samples from patients with lymph node metastasis (p < 0.05). Patients with Rad51 overexpression had a 69% two-year survival, 49% three-year survival, and 16% five-year survival, considerably worse than patients with negative Rad51 expression (p < 0.05). CONCLUSION:Our data suggest that Rad51 overexpression is correlated with malignant phenotypes of CRC and may predict poor prognosis for these patients.