Study Quantifies Overdiagnosis With Low-Dose CT for Lung CA
(HealthDay News) – In lung cancer screening, there is a relative mortality reduction with low-dose computed tomography (LDCT); however, limitations include a high rate of overdiagnosis, according to a study published online Dec. 9 in JAMA Internal Medicine.
Edward F. Patz Jr., MD, from the Duke University Medical Center in Durham, NC, and colleagues used data from the National Lung Screening Trial (NLST), which compared LDCT with chest radiography (CXR) among 53,452 persons at high risk for lung cancer. During a 6.4 year observation period, the excess number of lung cancers was estimated in the LDCT arm vs. the CXR arm.
The researchers identified 1,089 and 969 lung cancers reported in the LDCT and CXR arms, respectively. The probability of overdiagnosis was 18.5% for any lung cancer detected with LDCT screening; 22.5% for non-small-cell lung cancer detected by LDCT; and 78.9% for a bronchioalveolar lung cancer detected by LDCT. Among the 320 participants who would need to be screened in the NLST to prevent one death from lung cancer, the number of cases of overdiagnosis was 1.38.
"Whereas the NLST demonstrated a relative mortality reduction with LDCT, the limitations of the screening process, including the magnitude of overdiagnosis, should be considered when guidelines for mass screening programs are constructed," the authors write.