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. 2015 Aug;27(4):417–422. doi: 10.3978/j.issn.1000-9604.2015.06.09

Figure 1.

Figure 1

The Mayo Lung Project (MLP) was a randomized, controlled clinical trial of lung cancer screening that was conducted in 9,211 male smokers between 1971 and 1983 (intervention arm, n=4,618; usual-care arm, n=4,593). The intervention arm was offered chest X-ray and sputum cytology every 4 months for 6 years. Extended follow-up of MLP participants did not reveal a lung cancer mortality reduction for the intervention arm. The median follow-up time was 20.5 years. Lung cancer mortality was 4.4 [95% confidence interval (CI), 3.9-4.9] deaths per 1,000 person-years in the intervention arm and 3.9 (95% CI, 3.5-4.4) in the usual-care arm (two-sided P: for difference =0.09). Similar mortality but better survival for individuals in the intervention arm indicates that some lesions with limited clinical relevance may have been identified in the intervention arm. Data from Marcus PM, Bergstralh EJ, Fagerstrom RM, Williams DE, Fontana R, Taylor WF, and Prorok PC. Lung cancer mortality in the Mayo Lung Project: Impact of extended follow-up. J Natl Cancer Inst 2000;92:1308-16.