No association of the eNOS gene polymorphisms with survival in patients with colorectal cancer

Endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) is involved in numerous physiologic and pathophysiologic process including tumor angiogenesis and apoptosis. Accordingly, the present study analyzed polymorphisms of eNOS gene and their impact on the prognosis for patients with colorectal cancer. Four hundred and forty-four consecutive patients with surgically resected colorectal adenocarcinoma were enrolled in the present study. The genomic DNA was extracted from fresh colorectal tissue and 2 polymorphisms of eNOS gene (eNOS T786C and eNOS G894T) determined using a real-time PCR genotyping assay. The 2 eNOS gene polymorphisms were successfully amplified, and the frequencies of each genotype are as follows [T786C: TT (82.2%), TC (16.9%), CC (0.9%); G894T: GG (82.0%), GT (17.3%), TT (0.7%)]. Multivariate survival analysis including stage, age, site of disease, and CEA level showed that these polymorphisms were not associated with survival. For the clinicopathologic parameters, CEA level and TNM stage were significant prognostic factors in a Cox model for survival. The eNOS gene polymorphisms investigated in this study were not found to be an independent prognostic marker for Korean patients with surgically resected colorectal cancer. However, further studies are warranted to clarify the role of the eNOS gene polymorphisms as a prognostic biomarker for colorectal patients with cancer.