Abstract. Lung adenocarcinoma, characterized by its early and aggressive local invasion and high metastatic potential, is the most frequently observed histological type of non-small-cell lung cancer (NSCLC). Visceral pleural invasion (VPI) caused by peripheral lung adenocarcinomas is closely associa

Lung adenocarcinoma, characterized by its early and aggressive local invasion and high metastatic potential, is the most frequently observed histological type of non-small-cell lung cancer (NSCLC). Visceral pleural invasion (VPI) caused by peripheral lung adenocarcinomas is closely associated with the poor prognosis of patients with NSCLC. The association between VPI and some clinicopathological characteristics has been observed in the past few decades. However, the molecular mechanism of VPI in lung adenocarcinomas is unknown. In the present, the expression level of microRNA (miR-)135b and epidermal growth factor receptor (EGFR) mutations using the reverse transcription-quantitative polymerase chain reaction and DNA sequencing, respectively. In addition, the present study aimed at exploring the association between the miR-135b level, EGFR mutations and VPI in peripheral lung adenocarcinoma. The results of the present study demonstrated that miR‐135b was significantly upregulated in lung adenocarcinoma compared with adjacent normal tissue and positively associated EGFR mutations in peripheral lung adenocarcinoma. Furthermore, it was identified that lung adenocarcinomas with EGFR mutations and miR-135b overexpression were more likely to invade visceral pleura. Taken together, these findings indicate that miR‐135b overexpression is positively associated with mutations to EGFR, which may promote the development of peripheral lung adenocarcinomas by the formation of VPI. This indicates that the two factors may serve as prognostic markers and molecular targets for the treatment of peripheral lung adenocarcinomas.