Baseline chest radiograph for lung cancer detection in the randomized Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

Hubert H. Humphrey Cancer Center, North Memorial Medical Center, Robbinsdale, MN 55422, USA.
Journal of the National Cancer Institute (Impact Factor: 12.58). 01/2006; 97(24):1832-9. DOI: 10.1093/jnci/dji430
Source: PubMed


The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was initiated in 1992 to examine cause-specific mortality reduction from screening for these four cancers in men and women. We report lung cancer detection results of the baseline screening round.
Of the 154,942 participants enrolled, who were aged 55-74 years with no history of PLCO cancers, 77,465 were randomly assigned to the intervention arm. Current or former smokers and never smokers in this arm received an initial single-view posterior-anterior chest radiograph.
In the initial screen, 5991 (8.9%, 95% confidence interval [CI] = 8.7% to 9.2%) of radiographs were suspicious for lung cancer: 8.2% (95% CI = 7.9% to 8.5%) for women and 9.6% (95% CI = 9.3% to 10.0%) for men. Rates were highest for older age groups and for smokers. Among those 5991 participants with a positive screen, 206 (3.4%, 95% CI = 3.0% to 3.9%) underwent biopsy examination, 126 (61.2%, 95% CI = 54.5% to 67.8%) of whom were diagnosed with lung cancer within 12 months of the screen (59 in women and 67 in men). The positive predictive value was 2.1% (95% CI = 1.7% to 2.5%), and 1.9 lung cancers were detected per 1000 screens. Among these cancers, 44% (95% CI = 35% to 52%) were stage I non-small-cell lung cancer. High rates of lung cancer were found in current smokers (6.3 per 1000 screens) and in former smokers who had smoked within the past 15 years (4.9 per 1000 screens). The lung cancer detection rate among never smokers was 0.4 per 1000 screens; this group accounted for 11% (95% CI = 5.6% to 16.6%) of the cancers identified.
In the baseline screen, nearly half the cancers were stage I. Whether this experience results in a reduction in lung cancer mortality is yet to be seen.

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Available from: John K Gohagan, Jan 24, 2014
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    • "The results of these case-control studies were obtained in scarcely defined target populations, were likely biased by self-selection and are yet to be confirmed in western countries. Randomized trials of LC screening by chest radiography performed in the 1970s [9,10] failed to answer the question of efficacy of radiographic screening, likely due to methodological flaws [11]; however, the possibility was recognized that a small but important benefit from annual CXR could have been missed [12-14]. The lung component of the Prostate, Lung, Colon and Ovarian (PLCO) cancer screening randomized trial was carried out to definitively assess the efficacy of CXR screening [15]. "
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