Sputum cytologic diagnosis of upper respiratory tract cancer.

Sputum cytologic testing has been applied in the screening of high-risk individuals for presymptomatic lung cancer. This same screening procedure sometimes identifies patients with upper respiratory tract cancers and thereby may permit earlier treatment. Patients enrolled in the Mayo Lung Project undergo sputum cytologic and chest roentgenographic screening at four-month intervals and are compared with matched controls who are not intensively screened. Experience to date indicates an incidence rate of approximately 1 per 1,000 per year of cancer in the upper respiratory and alimentary passages among males more than 45 years old who are heavy cigarette smokers. This compares with a rate of approximately 4 per 1,000 per year of lung cancer. Recognition of early cancer of the upper respiratory tract is an additional benefit of screening for lung cancer. Since cigarette smoking represents an etiologic agent common to both upper and lower respiratory tract cancers, tumors should be searched for in both sites in this high-risk population.