Preliminary results from the lung cancer screening arm of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial show that chest x-rays can detect early lung cancer in asymptomatic people. The downside, however, is that the screening produced many false positives.

Of the 67,038 men and women who received a baseline chest x-ray, 5991 (8.9%) were positive and required additional evaluation. Of those, 126 (2.1%) were diagnosed with cancer within 12 months (J Natl Cancer Inst 2005;97:1832-1839).

While the positive predictive value was low, 44% of detected cancers were stage I, which are curable with treatment. Whether this translates into a real reduction in mortality from lung cancer will have to wait until the data mature, said lead author Dr. Martin M. Oken, a radiologist at North Memorial Medical Center in Robbinsdale, MN.