Finding needles in a haystack: annual low-dose computed tomography screening reduces lung cancer mortality in a high-risk group.
ABSTRACT Lung cancer is a global health issue. Compared with other common malignancies, the prognosis is poor as many patients present with advanced disease. The National Lung Screening Trial (NLST) aimed to identify and treat early lung cancers using annual low-dose computed tomography (CT) screening in a high-risk group. When compared with chest x-ray screening, low-dose CT screening reduced lung cancer mortality by 20%; the NLST is the first lung cancer screening trial to demonstrate such a mortality benefit. However, we must wait for cost-effectiveness data from the NLST, as well as the results of ongoing European studies comparing low-dose CT with observation alone, before firm conclusions can be drawn regarding the overall benefits of introducing a CT screening program to clinical practice.
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ABSTRACT: Lung cancer is a substantial public health problem in western countries. Previous studies have examined different screening strategies for lung cancer but there have been no published systematic reviews. A systematic review of controlled trials was conducted to determine whether screening for lung cancer using regular sputum examinations or chest radiography or computed tomography (CT) reduces lung cancer mortality. The primary outcome was lung cancer mortality; secondary outcomes were lung cancer survival and all cause mortality. One non-randomised controlled trial and six randomised controlled trials with a total of 245 610 subjects were included in the review. In all studies the control group received some type of screening. More frequent screening with chest radiography was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23). A non-statistically significant trend to reduced mortality from lung cancer was observed when screening with chest radiography and sputum cytological examination was compared with chest radiography alone (RR 0.88, 95% CI 0.74 to 1.03). Several of the included studies had potential methodological weaknesses. Controlled studies of spiral CT scanning have not been reported. The current evidence does not support screening for lung cancer with chest radiography or sputum cytological examination. Frequent chest radiography might be harmful. Further methodologically rigorous trials are required before any new screening methods are introduced into clinical practice.Thorax 10/2003; 58(9):784-9. · 8.38 Impact Factor
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ABSTRACT: Although smoking is widely recognized as a major cause of cancer, there is little information on how it contributes to the global and regional burden of cancers in combination with other risk factors that affect background cancer mortality patterns. We used data from the American Cancer Society's Cancer Prevention Study II (CPS-II) and the WHO and IARC cancer mortality databases to estimate deaths from 8 clusters of site-specific cancers caused by smoking, for 14 epidemiologic subregions of the world, by age and sex. We used lung cancer mortality as an indirect marker for accumulated smoking hazard. CPS-II hazards were adjusted for important covariates. In the year 2000, an estimated 1.42 (95% CI 1.27-1.57) million cancer deaths in the world, 21% of total global cancer deaths, were caused by smoking. Of these, 1.18 million deaths were among men and 0.24 million among women; 625,000 (95% CI 485,000-749,000) smoking-caused cancer deaths occurred in the developing world and 794,000 (95% CI 749,000-840,000) in industrialized regions. Lung cancer accounted for 60% of smoking-attributable cancer mortality, followed by cancers of the upper aerodigestive tract (20%). Based on available data, more than one in every 5 cancer deaths in the world in the year 2000 were caused by smoking, making it possibly the single largest preventable cause of cancer mortality. There was significant variability across regions in the role of smoking as a cause of the different site-specific cancers. This variability illustrates the importance of coupling research and surveillance of smoking with that for other risk factors for more effective cancer prevention.International Journal of Cancer 11/2005; 116(6):963-71. · 6.20 Impact Factor
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ABSTRACT: Low-dose CT scan screening greatly improves the likelihood of detecting small nodules and, thus, of detecting lung cancer at a potentially more curable stage. To evaluate the cost-effectiveness of a single baseline low-dose CT scan for lung cancer screening in high-risk individuals, data from the Early Lung Cancer Action Project (ELCAP) was incorporated into a decision analysis model comparing low-dose CT scan screening of high-risk individuals (ie, those > or = 60 years with at least 10 pack-years of cigarette smoking and no other malignancies) to observation without screening. Cost-effectiveness was expressed as the incremental cost per year of life saved. The analysis adopted the perspectives of the health-care system. The probability of the different outcomes following the decision either to screen or not to screen an individual at risk was based on data from ELCAP and the Surveillance, Epidemiology, and End Results Registry or published data, respectively. The cost of the screening and treatment of patients with lung cancer was established based on data from the New York Presbyterian Hospital's financial system. The base-case analysis was conducted under the assumption of similar aggressiveness of screen-detected and incidentally discovered lung cancers and then was followed by multiple sensitivity analyses to relax these assumptions. The incremental cost-effectiveness ratio of a single baseline low-dose CT scan was 2,500 US dollars per year of life saved. The base-case analysis showed that screening would be expected to increase survival by 0.1 year at an incremental cost of approximately 230 US dollars. Only when the likelihood of overdiagnosis was > 50% did the cost effectiveness ratio exceed 50,000 US dollars per year of life saved. The cost-effectiveness ratios were also relatively insensitive to estimates of the potential lead-time bias. A baseline low-dose CT scan for lung cancer screening is potentially highly cost-effective and compares favorably to the cost-effectiveness ratios of other screening programs.Chest 08/2003; 124(2):614-21. · 5.85 Impact Factor