Lung cancer screening - an overview about chances and risks

Lung cancer is a leading cause of death worldwide. Patients are usually diagnosed at an advanced stage and have a very poor prognosis. In Switzerland, lung cancer is the most frequent cause of cancer death in men and the second most frequent cause of cancer death in women. Programmes to prevent individuals from initiating to smoke and to support smokers to quit are the most effective lung cancer prevention strategy. Whether routine screening for lung cancer in smokers is effective to reduce lung cancer related morbidity and mortality remains questionable. We summarize the evidence of five recent randomised controlled trials on routine screening for lung cancer in smokers. One study found no benefit of periodic conventional chest X-rays as compared to usual care without regular imaging for reducing lung cancer death. In four other trials, low-dose computer tomography (LDCT) was compared to conventional chest X-rays and to usual care. Only the largest trial, the US based National Lung Cancer Screening Trial (NLST), demonstrated a statistically significant reduction of lung cancer mortality of LDCT compared to conventional chest X-rays whereas three European trials could not prove any benefit. The results of the NLST need to be interpreted with care due to limited generalizability to European settings. LDCT screening had an unacceptable high rate of false positive findings resulting in an enormous use of resources for diagnostic work-up. Whether LDCT screening is associated with an acceptable incremental cost-effectiveness ratio still warrants further investigation.