Lung cancer is one of the most common cancers in the world and has received much attention in recent years due to its association with high morbidity and mortality. 1 In 2018, the World Health Organization reported the estimated morbidity and mortality associated with lung cancer to be about 11.6% and 18.4%, respectively; in China, its incidence and mortality remain high in both men and women. 2 Lung cancer has two main subtypes, small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). Based on pathology, NSCLC has various subtypes, such as adenocarcinoma (LUAD), squamous carcinoma (LUSD) and adenosquamous carcinoma. LUAD, one of the most malignant cancers, is often diagnosed at a late stage and has a poor clinical prognosis. 3 In addition, it has been reported that LUAD is associated with a high degree of tumour metastasis. 4,5 Therefore, it is of extreme importance to research the factors associated with lung cancer progression and its poor clinical prognosis.