False Positives in the National Lung Screening Trial (NLST)

The tables show data from the NLST, with true and false positive screens at screening round #1, 2 and 3.

• NLST is a randomized control trial studying the effect of low-dose CT screening vs. CXR in reduction of lung cancer-specific mortality. The interim result had been announced in October 2010, which showed a 20% reduction in mortality of those who had screened with low-dose CT.
• Overall positivity rates (non-calcified nodule 4 mm or greater in size and other findings potentially related to lung cancer) for the NLST are 24.2% at low-dose CT, and 6.9% at CXR
• Of all positives, only 2-5% (at CT) and 4-7% (at CXR) of cases are truly lung cancer.
• Number of false positives are relatively high.
• To reduce false positives, systematic and multidisciplinary approach in establishing the regimen for low-dose CT lung cancer screening is needed.

Reference:

Gierada DS. RSNA 2010