Cochrane Summaries

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Screening for lung cancer

Manser R, Lethaby A, Irving LB, Stone C, Byrnes G, Abramson MJ, Campbell D
Published Online: 
21 June 2013

Lung cancer is the most common cause of cancer-related death in the western world. It takes about 20 years to develop and cigarette smoking is a known cause. Most lung cancers are not found early in the development of the disease. Regular screening is offered to those considered to be at high risk of contracting the disease. Trials were made of early detection methods such as the testing of sputum, x-ray and computed tomography (CT) scanning of the chest to see whether they made a difference to the number of people who were treated by surgery and the number of people who died as a result of the disease. This review examined the evidence from nine trials (with a total of 453,965 participants) and found that early screening with chest X-ray or sputum testing does not reduce the number of people who die from lung cancer. Screening with low-dose chest CT was found in one large trial to reduce the number of people who die from lung cancer but this trial only included very high-risk smokers and ex-smokers. CT screening however is associated with a high number of false positive results and there are also some people who have lung cancer detected and treated but in whom this cancer may not have progressed to cause death in their lifetime, even in the absence of treatment (referred to as overdiagnosis). More research is needed about the relative harms and benefits of CT screening in individuals at lower risk for lung cancer.