Abstract
The sensitivity and specificity of sputum cytology for lung cancer screening were evaluated in a high-risk group. A total of 4718 screenees who were 50 years old or more and whose Cigarette Index was 600 or more underwent screening tests by sputum cytology and chest X-ray in 12 municipalities from 1986 to 1987.All of the screenees were followed up until the end of 1988 by means of the record linkage of the Miyagi Cancer Registry.Sensitivity and specificity were evaluated in two ways, i.e.by defining screening as false negative in cases in which the interval between the negative screening and the diagnosis of lung cancer was less than one year, and by defining screening as false negative in cases in which the interval from the negative screening to the diagnosis of lung cancer or to positive screening which led to the diagnosis of lung cancer was less than one year.According to these methods, the sensitivities and specificities for lung cancer were 53.8% and 99.8%, 38.9% and 99.8%, respectively. The sensitivity and specificity of squamous cell carcinoma of the lung were 77.8% and 99.8%, 70% and 99.8%. The values for the hilar type of squamous cell carcinoma of the lung were 87.5% and 99.8%, and 71.4% and 99.8%, respectively.
