Abstract 3628: Benign disease prevalence after surgical lung resection varies geographically in the US Medicare population, implications for lung cancer screening.
Authors: Deppen Stephen A. , Phillips Sharon , McPheeters Melissa , Aldrich Melinda C. , Blume Jeffery , Penson David F. , Shyr Yu , Grogan Eric L. 
Published: August 2014

Abstract
Purpose: The National Lung Screening Trial (NLST) demonstrated that screening computed tomography (CT) reduces mortality caused by lung cancer and clinical societies and patient advocacy groups have recommended screening high risk individuals. Screening CT scan of the chest reduced lung cancer mortality in this trial but 96% of anomalies were false positives, 24% of lung surgeries resulted in a benign diagnosis. The overall mortality rate from procedures was 1.2% in the trail. The benign disease prevalence after surgical biopsy is not known at the state level and if these prevalences differ across the United States, then a nationwide screening regimen may have geographically varying success. The purpose of this study is to determine the benign disease point prevalence after surgical lung resection at the state level using a national dataset.
Methods: We examined the point prevalence of benign disease after lung surgery in a retrospective cohort being evaluated for known or suspected lung cancer. The MEDPAR Hospital National Limited Data Set from 2009 was used to identify patients who had undergone lung surgery by ICD-9CM codes. Patients less than 19 years old or who had diseases not arising from a lung lesion were excluded. Malignancy and benign disease were determined by ICD-9CM codes. The benign diagnosis prevalence was estimated at the state level by dividing the total number of benign cases by the sum of the benign cases and malignant cases. Benign disease point prevalence was compared between states using Pearson chi-square test.
Results: There were 25,362 patients who had a lung operation for known or suspected lung cancer. Among these, 2,312 (9.1%) had a benign diagnosis. Benign diagnosis was more frequent among women (9.8%) than men (8.5%) after surgery. Crude in hospital mortality rate for all patients was 2.3%. The mortality rate for patients with benign disease was 2.1%. Prevalence of benign disease varied significantly (chi-sq p&lt;0.001) across states from a low of 1.3% in Vermont to a high of 25.0% in Hawaii. Median benign disease by state was 8.8% (IQR: 7.8 - 10.9).
Conclusion: Benign disease prevalence after lung surgery varies widely by state and resulted in a mortality rate of 2.1 percent. Cause of observed differences is not known but may be due to practice variation or locally endemic lung diseases and should be investigated to determine the impact to a national lung cancer screening program.
Citation Format: Stephen A. Deppen, Sharon Phillips, Melissa McPheeters, Melinda C. Aldrich, Jeffery Blume, David F. Penson, Yu Shyr, Eric L. Grogan. Benign disease prevalence after surgical lung resection varies geographically in the US Medicare population, implications for lung cancer screening. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3628. doi:10.1158/1538-7445.AM2013-3628