More than 18% of all lung cancers detected by low-dose CT appeared to represent an overdiagnosis, revealing indolent or clinically insignificant lesions, according to a study.
Researchers applied data from the National Lung Screening Trial, which compared low-dose CT screening vs. chest radiography among more than 53,000 people at high risk for lung cancer, to derive the estimate of overdiagnosis.
Results were published online Dec. 9 at JAMA Internal Medicine.
Among 1,089 lung cancers reported in the low-dose CT group, an estimated 18.5% (95% CI, 5.4% to 30.6%) represented an overdiagnosis. Also, researchers wrote, 22.5% (95% CI, 9.7% to 34.3%) of non-small cell lung cancer detected by low-dose CT represented an overdiagnosis, and 78.9% (95% CI, 62.2% to 93.5%) of bronchioalveolar lung cancers detected by low-dose CT represented an overdiagnosis.
There is no “watchful waiting” for lung cancer, the authors noted, and early stage lesions are treated aggressively because it’s not possible to distinguish which lesions will progress.
“In the future, once there are better biomarkers and imaging techniques to predict which individuals with a diagnosis of lung cancer will have more or less aggressive disease, treatment options can be optimized, and a mass screening program can become more valuable,” the authors concluded.