Study On Rad51 Overexpression On Rectal Cancer

Background: Rad51 plays an important role in the development of solid tumors. However, the association between Rad51 expression and clinic pathological characteristics of human rectal cancer is not well defined. This study aimed to examine the expression of Rad51 in human rectal cancer and investigated the relationship between its expression and the prognosis of rectal cancer. Methods: The clinicopathological data of 54 patients diagnosed with rectal cancer who were received surgery between 2006 and 2008 were collected. The expression of Rad51 in paraffin-embedded tumor specimens was detected by immunohistochemistry. Twenty adjacent cancer tissue samples and twenty normal tissue samples were used as control groups. The correlation between the expression level of Rad51 with clinicopathological features and prognosis were analyzed. Results: The positive expression rates of Rad51 in rectal cancer, paracancerous tissue and normal tissues were 68%, 47% and 26%, respectively. The expression level of Rad51 in rectal cancer was not significantly different from paracancerous tissue (P>0.05), but was significantly higher than normal tissues (P<0.05). Rad51 expression level in the poorly differentiated group is significantly higher than that in the well differentiated group, and also higher in the lymph node positive group than in the node negative group (P<0.05). The 2, 3, and 5 year-survival for Rad51 positive patients were 69%, 49%, and 16%, respectively, which was significantly lower than those patients (90%, 82%, 78%, respectively) with Rad51 negative (P<0.05). Conclusion: The data suggest that Rad51 expression is correlated with malignant phenotypes of rectal cancer and it may serve as a novel prognostic factor for rectal cancer.