Circulating miRNA signature for early diagnosis of lung cancer

Abstract

Non‐small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Despite the numerous recent studies on NSCLC genomics, molecular mechanisms of disease and the development of targeted therapies, which improve treatment responses to a certain extent, the overall 5‐year survival rate is only around 10–15%. The main reason for such a low 5‐year survival rate has long been attributed to late diagnosis of the disease in three quarters of patients, resulting in advanced and inoperable diseases. Lung cancer studies for decades have attempted to develop screening modalities that allow early diagnosis. However, in contrast to the success in prognostic and predictive biomarker research during the past 10 years, the progress in early lung cancer screening is still limited and restricted to imaging studies. Chest radiography and sputum cytology screening programs in the 1970s had failed to reduce cancer mortality. Low‐dose spiral chest computed tomography (LDCT) screening trials carried out in the 2000s generally resulted in a significant increase in the number of early‐stage lung cancer diagnoses, but without apparent reduction in development of advanced cancers or cancer mortality (Pastorino, 2010). The first successful large LDCT screening trial reported is the National Lung Screening Trial (NSLT). It demonstrates a 20% reduction of cancer mortality in the LDCT screening arm compared to the chest radiography arm (http://www.cancer.gov). The results from these LDCT screening studies highlight several issues worth noticing. First, LDCT leads to over‐diagnosis of benign/indolent pulmonary lesions and cause significant increase of unnecessary surgical intervention (Bach, 2008 …