Screening for lung cancer: time for large-scale screening by chest computed tomography

Abstract

Lung cancer is the leading cause of cancer death worldwide. Age and smoking are the primary risk factors for lung cancer. Treatment based on surgical removal in the early stages of the disease results in better survival. Screening programmes for early detection that used chest radiography and sputum cytology failed to attain reduction of lung cancer mortality. Screening by low-dose computed tomography (CT) demonstrated high rates of early-stage lung cancer detection in a high-risk population. Nevertheless, no mortality advantage was manifested in small randomised control trials. A large randomised control trial in the U.S.A., the National Lung Screening Trial (NLST), showed a significant relative reduction of 20% in lung cancer mortality and 6.7% reduction in total mortality, yet no reduction was evidenced in the late-stage prevalence. Screening for lung cancer by low-dose CT reveals a high level of false-positive lesions, which necessitates further noninvasive and invasive evaluations. Based primarily on the NLST eligible criteria, new guidelines have recently been developed by major relevant organisations. The overall recommendation coming out of this collective work calls for lung cancer screening by low-dose CT to be performed in medical centres manned by specialised multidisciplinary teams, as well as for a mandatory, pre-screening, comprehensive discussion with the patient about the risks and advantages involved in the process. Lung cancer screening is on the threshold of a new era, with ever more questions still left open to challenge future studies.