High Lung Cancer Incidence in Heavy Smokers Following Hospitalization due to Pneumonia

Abstract Introduction The rate of lung cancer incidence following pneumonia in heavy smokers is unknown. Heavy smokers hospitalized due to community-acquired pneumonia might be at high risk for subsequent lung cancer. The primary objective of this study was to determine lung cancer incidence in this high-risk population. Patients and Methods This was a single-center, retrospective cohort study that included heavy smokers hospitalized due to community-acquired pneumonia between January 1, 2007 and December 31, 2011 in Beilinson hospital, a large community hospital and tertiary center. Patients were identified by International Classification of Diseases, Ninth Revision coding from the hospital's registry. Two physicians reviewed every patient's medical file for patient demographics, smoking history, lung cancer risk factors, and anatomical location of pneumonia. Data were cross-checked with the database at the national cancer registry for new diagnoses of cancer. Results There were 381 admissions for community-acquired pneumonia included in the final analysis. Thirty-one cases (8.14%; 95% confidence interval [CI], 5.9%-11.2%) of lung cancer were diagnosed during the first year after hospitalization. Lung cancer incidence was significantly higher in patients who had upper-lobe pneumonia (23.8%; 95% CI, 14.9%-40%). Lung cancer was located within the lobe involved by the pneumonia in 75.8% of patients. Conclusions A high lung cancer rate was found in heavy smokers admitted due to community-acquired pneumonia. The association was especially strong for patients with upper-lobe pneumonia. Screening with chest computed tomography should be strongly considered for these patients.