Clinical significance of circ-MTHFD2 in diagnosis, pathological staging and prognosis of NSCLC

OBJECTIVE: To explore the clinical significance of circ-MTHFD2 in the diagnosis, pathological staging, and prognosis of nonsmall cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 100 pairs of cancer tissues and adjacent tissues were surgically removed from NSCLC patients treated from July 2011 to January 2013 in our hospital were selected. All tissue samples were pathologically confirmed. Real Time-Polymerase Chain Reaction (qRT-PCR) was adopted to detect the expression of circ-MTHFD2 in NSCLC samples and its characteristic as a circular ribonucleic acid (circRNA). The receiver operating characteristic (ROC) curve was drawn to determine the diagnostic potential of circ-MTHFD2 in NSCLC. The relationship between circ-MTHFD2 expression and the clinical characteristics of NSCLC patients was analyzed by the χ²-test. Kaplan- Meier survival curves were depicted to assess the prognostic potential of circ-MTHFD2 in NSCLC. The effect of circ-MTHFD2 on the overall survival rate of NSCLC patients was uncovered by introducing the Cox proportional hazards model. RESULTS: The expression of circ-MTHFD2 in cancer tissues of NSCLC patients was higher than that in adjacent tissues (p<0.05), and there was no remarkable difference in the expression of circ-MTHFD2 before and after RNase R digestion (p>0.05). The area under the curve (AUC) of circ-MTHFD2 ROC was 0.701, with the cut-off value of 3.534, 90% sensitivity and 71% specificity. Circ-MTHFD2 expression was closely associated with smoking history, tumor size, tumor- node-metastasis (TNM) stage, lymph node metastasis, and recurrence in NSCLC patients (p<0.05). The prognosis of NSCLC patients with high expression of circ-MTHFD2 was evidently poorer than those with low expression. High expression of circ-MTHFD2 was an independent risk factor affecting the prognosis in NSCLC (p<0.05). CONCLUSIONS: The high expression of circ- MTHFD2 has clinical significance in the diagnosis, pathological staging, and prognosis of NSCLC.