To evaluate the value of microRNA (miR)-146b-3p, miR-15b-5p, and miR-16-5p in the differential diagnosis and prognosis evaluation of benign and malignant pulmonary nodules.

Totally 139 patients with pulmonary nodules admitted to our hospital were selected as the research subjects between June 2018 and June 2020. Based on postoperative pathological results or biopsy results, the patients were divided into a benign group (n=75) and a malignant group (n=64). Serum miR-146b-3p, miR-15b-5p, and miR-16-5p in the two groups were measured, and their diagnostic value in benign and malignant nodules was analyzed. The relationship between serum miR-146b-3p, miR-15b-5p, or miR-16-5p and pathological characteristics in the malignant group was analyzed. The prognosis of patients in the malignant group was evaluated, and the prognostic value of serum miR-146b-3p, miR-15b-5p, and miR-16-5p was analyzed.

Serum miR-146b-3p and miR-15b-5p in the benign group were significantly lower than those in the malignant group (P＜0.05), and miR-16-5p was significantly higher than that in the malignant group (P＜0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) values of serum miR-146b-3p, miR-15b-5p, and miR-16-5p, alone and in combination, to diagnose benign and malignant nodules were 0.803, 0.786, 0.889, and 0.962, respectively. Serum miR-146b-3p, miR-15b-5p, and miR-16-5p were related to differentiation degree, lymph node metastasis, and clinical stage (P＜0.05). Spearman correlation analysis showed that both serum miR-146b-3p and miR-15b-5p were significantly negatively correlated with differentiation degree (r=-0.534 and -0.468, respectively, P＜0.05), and significantly positively correlated with lymph node metastasis (r=0.582 and 0.608, respectively, P＜0.05) and clinical stage (r=0.486 and 0.519, respectively, P＜0.05). Serum miR-16-5p was significantly positively correlated with differentiation degree, and significantly negatively correlated with lymph node metastasis and clinical stage (r=0.412, -0.563, and -0.657, respectively, P＜0.05). In the malignant group, serum miR-146b-3p and miR-15b-5p in patients with a poor prognosis were significantly higher than those in patients with a good prognosis, and miR-16-5p was significantly lower in patients with a poor prognosis than that in patients with a good prognosis (P＜0.05). ROC curve analysis showed that the AUC values of serum miR-146b-3p, miR-15b-5p, miR-16-5p, alone and in combination, for evaluating the prognosis of patients with malignant nodules were 0.799, 0.772, 0.774, and 0.881, respectively.

Serum miR-146b-3p, miR-15b-5p, and miR-16-5p are closely related to clinical characteristics of benign and malignant pulmonary nodules and the prognosis of patients with malignant nodules. Combination of the three is of high value in the differential diagnosis of benign and malignant pulmonary nodules.