Objective To investigate the expression and clinical significance of miR-635 and miR-519d in patients with gastric cancer. Methods A total of 116 patients with gastric cancer admitted between July 2018 and July 2020 were enrolled. Gastric cancer tissues and matched adjacent tissues obtained during surgery were collected. The expression levels of miR-635 and miR-519d were detected by quantitative real-time PCR (qRT-PCR). Kaplan–Meier survival curves were used to analyze the relationship between miR-635 and miR-519d expression and patient prognosis. Cox regression analysis was performed to identify prognostic factors. ROC curves were plotted to assess the predictive value of miR-635 and miR-519d for prognosis, and the prognostic model was internally validated using the Bootstrap method. Results The expression levels of miR-635 and miR-519d differed significantly between gastric cancer tissues and adjacent tissues (P 0.05). miR-635 and miR-519d were associated with TNM stage, degree of differentiation, lymph node metastasis, and depth of infiltration (P 0.05). Their expression levels in the death group were significantly lower than those in the survival group (P 0.05). The AUC of the combined detection of miR-635 and miR-519d for predicting prognosis was 0.935, which was superior to that of either marker alone (Z combination vs miR-635 = 2.321, Z combination vs miR-519d = 2.043, P 0.05). The 3-year survival rates of patients with moderately decreased miR-635 or miR-519d expression were higher than those of patients with severely decreased expression (χ 2 = 26.038 and 14.255, respectively; P 0.05). Multivariate Cox regression analysis showed that TNM stage, degree of differentiation, lymph node metastasis, and depth of infiltration were risk factors affecting prognosis (P 0.05), whereas miR-635 and miR-519d were protective factors (P 0.05). Internal validation showed a C-index of 0.935, and the Hosmer–Lemeshow test yielded χ 2 = 7.786, P = 0.742. Conclusion miR-635 and miR-519d are significantly downregulated in gastric cancer tissues and are associated with clinicopathological characteristics and prognosis. Their combined detection can effectively predict the prognosis of patients with gastric cancer.
Liu et al. (Thu,) studied this question.