The contribution of discrimination analysis to the diagnostic decision in patients with lung carcinoma.

A set of 620 patients was examined. Out of them, 245 suffered from lung carcinoma of different type and stage, 28 suffered from other malignant tumors, 37 were affected with benign tumors, and 166 were suffering from a nonmalignant respiratory disease (tuberculosis, nonspecific pneumonia, chronic bronchitis, abscesses, cysts, asthma, lung fibrosis, bronchiectasis and sarcoidosis). In addition to these patients, 144 blood donors were examined who represented the control group of healthy individuals. In a blind test another set of 266 persons was examined. By completing the values of selected markers (orosomucoid, prealbumin, glycoprotein electrophoresis, erythrocyte sedimentation, age of the individual, and the number of smoked cigarettes) into the discrimination rule and by calculating the discrimination function, a sensitivity of 80.6% and a specificity of 75.6% were obtained. A comparative cytological examination of the same set revealed lower sensitivity (61.0%) but higher specificity (98.0%). These values were verified in a blind test, as the patients were admitted to the hospital. Sensitivity in lung cancer was found to be 83.9%; in nonmalignant diseases the respective value was 77.1%. This approach can be applied to individuals suspect of cancer, in secondary prevention and in individuals with a high risk of lung cancer.