BACKGROUND

Lung cancer is the leading cause of cancer-related death in the United States and worldwide. No major professional organizations, including the U.S. Preventive Services Task Force (USPSTF), currently recommend screening for lung cancer.

PURPOSE

To examine the evidence evaluating screening for lung cancer with chest x-ray, sputum cytology, and low-dose computerized tomography (CT) to aid the USPSTF in updating its recommendation on lung cancer screening.

DATA SOURCES

MEDLINE®, the Cochrane Library, reviews, editorials, and experts.

STUDY SELECTION

Studies that evaluated mass-screening programs for lung cancer involving the tests of interest. All studies were reviewed, but only studies with control groups were rated in quality since these would most directly influence the USPSTF screening recommendation.

DATA EXTRACTION

Data were abstracted to data collection forms. Studies were graded according to criteria developed by the USPSTF.

DATA SYNTHESIS

None of the 6 randomized trials of screening for lung cancer with chest x-ray alone or with sputum cytology have been shown to benefit those screened. All studies were limited by some level of screening occurring in the control population. Five case-control studies from Japan have suggested benefit to both high- and low-risk men and women. All studies are limited by potential healthy screenee bias. Six cohort studies evaluated screening CT and showed that when CT is used to screen for lung cancer, lung cancer was diagnosed at an earlier stage than in usual clinical care. However, these studies did not have control groups, making mortality evaluation difficult. In addition, the studies demonstrated a high rate of false-positive findings.

CONCLUSIONS

Current data do not support screening for lung cancer with any method. These data, however, are also insufficient to conclude that screening does not work, particularly in women. Two randomized trials of screening with chest x-ray or low-dose CT are currently underway and will better inform lung cancer screening decisions.