THE IMPORTANCE OF SPUTUM CYTOLOGY IN THE DIAGNOSIS OF LUNG-CANCER - ACOST-EFFECTIVENESS ANALYSIS

Study objective: To assess the potential health and cost effects of in itial testing with sputum cytology to diagnose lung cancer. Design: Co st-effectiveness analysis. Data sources: Surveillance Epidemiology and End Results (SEER) program; cost data from Northern California Kaiser Permanente Hospitals and Universities of Stanford and Iowa; National Center for Health Statistics; and a MEDLINE search.Interventions: The use of sputum cytologies preceding other tests (ie, fine-needle aspira tion, bronchoscopy, thoracoscopy) in patients with suspected lung canc er. Main outcome measures: Mortality associated with testing and initi al surgical treatment (eg, performance of thoracoscopy to remove a loc al-stage, centrally located cancer), cost of testing and initial treat ment, life expectancy, lifetime cost of medical care, and cost-effecti veness. Results: In central lesions, sputum cytology as the first test was the dominant strategy because it both lowers medical-care costs ( $2,516 per patient) and lowers the mortality risk (19 deaths in 100,00 0 patients) of the evaluation without adversely affecting long-term su rvival. In peripheral lesions, sputum cytology costs less then $25,000 per year of life saved if the pretest probability of cancer exceeds 5 0%, The estimated annual savings of adopting sputum cytology as the fi rst test for diagnosing lung cancer in the United States is at least $ 30 million. Conclusions: Experience in regional centers indicates that sputum cytologic testing is infrequently ordered before implementing invasive diagnostic techniques, even in patients with central lung mas ses, The study findings suggest that sputum cytology as the first test in suspected lung cancer is likely to be cost saving without adversel y affecting patient outcomes.