Jerome M Reich1, Jong S Kim2, James W Asaph3. 1. Thoracic Oncology Program, Earle A. Chiles Research Institute, Portland, OR. Electronic address: Reichje@isp.com. 2. Fariborz Maseeh Department of Mathematics and Statistics, Portland State University, Portland, OR. 3. Thoracic Oncology Program, Earle A. Chiles Research Institute, Portland, OR.
Abstract
BACKGROUND: The aim of this study was to estimate the effect of lobectomy on life expectancy in healthy smokers and consider the implications for lung cancer screening. MATERIALS AND METHODS: In a retrospective cohort study that provided a minimum of 15 years of follow-up, we analyzed lung cancer survival, all-cause survival, and fatality (1-survival) of 261 persons with stage I non-small-cell lung cancer who underwent lobectomy at Portland Providence Medical Center between 1978 and 1994. We: (1) compared 5-year disease-free fatality (non-lung-cancer fatality) with lung cancer fatality; and (2) based on actuarial data that demonstrated life expectancy equivalence of the healthiest smokers (whom we assumed would be comparable with subjects judged eligible for lobectomy) in the US population, we compared their long-term, disease-free survival (our primary end point) with actuarial expectations by computing the Kaplan-Meier survival function of the differences between lifetimes since surgery in disease-free persons versus matched, expected remaining lifetimes in the US population. RESULTS: (1) Five-year disease-free fatality (16.1%) was 58% as high as 5-year lung cancer fatality (27.6%); (2) disease-free survival was reduced by 6.9-years (95% confidence interval, 5.5-8.3), 41% of actuarial life expectancy (17 years). The divergence from expected survival took place largely after 6 years of follow-up. CONCLUSION: Lobectomy materially diminishes long-term disease-free survival in the healthiest smokers--persons judged healthy enough to tolerate major surgery and to have sufficient pulmonary reserve to sustain loss of one-fifth of their lung tissue. In screened populations, diminished survival in overdiagnosed persons will offset, to an undetermined extent, the mortality benefit imparted by preemption of advanced lung cancer.
BACKGROUND: The aim of this study was to estimate the effect of lobectomy on life expectancy in healthy smokers and consider the implications for lung cancer screening. MATERIALS AND METHODS: In a retrospective cohort study that provided a minimum of 15 years of follow-up, we analyzed lung cancer survival, all-cause survival, and fatality (1-survival) of 261 persons with stage I non-small-cell lung cancer who underwent lobectomy at Portland Providence Medical Center between 1978 and 1994. We: (1) compared 5-year disease-free fatality (non-lung-cancer fatality) with lung cancer fatality; and (2) based on actuarial data that demonstrated life expectancy equivalence of the healthiest smokers (whom we assumed would be comparable with subjects judged eligible for lobectomy) in the US population, we compared their long-term, disease-free survival (our primary end point) with actuarial expectations by computing the Kaplan-Meier survival function of the differences between lifetimes since surgery in disease-free persons versus matched, expected remaining lifetimes in the US population. RESULTS: (1) Five-year disease-free fatality (16.1%) was 58% as high as 5-year lung cancer fatality (27.6%); (2) disease-free survival was reduced by 6.9-years (95% confidence interval, 5.5-8.3), 41% of actuarial life expectancy (17 years). The divergence from expected survival took place largely after 6 years of follow-up. CONCLUSION: Lobectomy materially diminishes long-term disease-free survival in the healthiest smokers--persons judged healthy enough to tolerate major surgery and to have sufficient pulmonary reserve to sustain loss of one-fifth of their lung tissue. In screened populations, diminished survival in overdiagnosed persons will offset, to an undetermined extent, the mortality benefit imparted by preemption of advanced lung cancer.