Lung cancer mortality in males screened by chest X-ray and cytologic sputum examination: a preliminary report.

Observations from the continuing JHLP lung cancer screening study provide no clear evidence that mass screening by chest X-ray and sputum cytology, plus prompt appropriate treatment, reduces mortality du to lung cancer. No reduction in lung cancer deaths is observed in the JHLP when compared with the number of lung cancer deaths expected from the experience of two unscreened male populations of the same age and smoking status serving as population studies. Possible reasons for the lack of demonstrable decrease in mortality, even though "early" cases have been detected, include: (1) an insufficient passage of time for slowly growing cancers to become apparent in the control group, (2) ineffective therapy, and (3) the multifocal nature of pulmonary neoplasms. Additional study will be required to provide a definitive answer regarding the benefit, if any, of lung cancer screening.