The prognostic value of miR-34a expression in completely resected gastric cancer: tumor recurrence and overall survival.

The prognosis of gastric cancer is mainly linked to tumor recurrence. MicroRNA-34a (miR-34a) is a direct transcriptional target of p53 and links tumor suppressor function and the oncogenic pathways in some cancers. However, the role of miR-34a in predicting prognosis of gastric cancer has not been fully elucidated. In this study, we aimed to investigate the expression level of miR-34a and its prognostic value in gastric cancer. A total of 137 consecutive gastric cancer patients who underwent gastrectomy with D2 lymph node dissection were included in this study. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect miR-34a expression in gastric cancer tissues and adjacent normal tissues. The results showed that the levels of miR-34a expression were significantly decreased in the tumor tissues compared with the adjacent normal tissues (P<0.001). Low miR-34a expression level was associated with lymph node involvement (P=0.004), advanced TNM stage (P=0.006), poor tumor differentiation (P=0.024), high tumor recurrence rate (P=0.008), and poor five-year survival (P<0.001). The median time to recurrence and median overall survival time were significantly shorter in patients with low miR-34a levels compared with those with high miR-34a levels (P=0.028 and P=0.021, respectively). Furthermore, when analyzed with a multivariate Cox regression model, a low miR-34a level was significantly correlated with high recurrence rate and poor overall survival. Taken together, our results suggest that downregulation of miR-34a in gastric cancer is associated with high recurrence rate and poor overall survival and that miR-34a may be served as a prognostic marker for gastric cancer.