SPUTUM SCREENING BY QUANTITATIVE MICROSCOPY - A REEXAMINATION OF A PORTION OF THE NATIONAL-CANCER-INSTITUTE COOPERATIVE EARLY LUNG-CANCER STUDY

Objective: To investigate the hypothesis that image cytometry of sputu m specimens can detect squamous carcinoma without requiring visually a bnormal cells. Design: The sensitivity and specificity of image cytome try were evaluated in a case-control study. Material and Methods: Seve nty-three sputum slides from the Mayo portion of the National Cancer I nstitute Cooperative Early Lung Cancer Study were restained by a modif ied Feulgen method. We examined 40 slides from 9 patients in whom squa mous carcinoma developed and 33 slides from 11 patients in whom no can cer developed during a follow-up of at least 5 years. Images of normal epithelial nuclei were collected by using an automated image cytomete r. Discriminant analysis was used to determine differences in DNA dist ribution of normal nuclei in sputum specimens from noncancer patients versus normal nuclei in sputum samples from patients in whom carcinoma developed. Results: By using features based on DNA distribution, 74% correct classification of nuclei was possible without human review of the material and without the use of visually abnormal nuclei. A receiv er operating characteristic curve demonstrated sensitivities and speci ficities, including 40% sensitivity and 90% specificity. Conclusion: A lthough this study was limited to 20-year-old slides and squamous cell carcinoma, automated image cytometry detected a substantial proportio n of patients with squamous cell cancer without using visually abnorma l nuclei.