Screening for lung cancer: The Mayo lung project revisited

Abstract

Background. The Mayo Lung Project (MLP) reported lung cancer incidence and mortality in a population offered chest radiographs and sputum cytologic screening examinations every 4 months and a population offered only the Mayo Clinic advice to undergo annual examination. No mortality benefit attributable to screening was observed after 6 years of observation and at least 1 year of follow‐up. Methods. The authors describe a simulation study designed to estimate from Mayo data the parameters in a mathematical model of the natural history of lung cancer and to estimate the potential benefit associated with periodic screening of high‐risk people starting at 45 years of age. Results. It was found that the mean duration of Stage non–small cell lung cancer is at least 4 years and that rates of Stage I detectability and curability are less than 25% and 35%, respectively. Conclusions. A trial of the magnitude, duration, and contamination of the MLP would have a less than 20% probability of showing significant benefit from screening; however, long‐term annual screening might result in a modest decrease in lung cancer mortality, ranging from 0% to 13%. A greater benefit would accrue from improved detection and treatment. Copyright © 1993 American Cancer Society