***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The effects of low-dose CT screening on disease stage shift , mortality and overdiagnosis are unclear . Lung cancer findings and mortality rates are reported at the end of screening in the Danish Lung Cancer Screening Trial . Methods 4104 men and women , healthy heavy smokers/former smokers were r and omised to five annual low-dose CT screenings or no screening . Two experienced chest radiologists read all CT scans and registered the location , size and morphology of nodules . Nodules between 5 and 15 mm without benign characteristics were rescanned after 3 months . Growing nodules ( > 25 % volume increase and /or volume doubling time<400 days ) and nodules > 15 mm were referred for diagnostic workup . In the control group , lung cancers were diagnosed and treated outside the study by the usual clinical practice . Results Participation rates were high in both groups ( screening : 95.5 % ; control : 93.0 % ; p<0.001 ) . Lung cancer detection rate was 0.83 % at baseline and mean annual detection rate was 0.67 % at incidence rounds ( p=0.535 ) . More lung cancers were diagnosed in the screening group ( 69 vs 24 , p<0.001 ) , and more were low stage ( 48 vs 21 stage I – IIB non-small cell lung cancer ( NSCLC ) and limited stage small cell lung cancer ( SCLC ) , p=0.002 ) , whereas frequencies of high-stage lung cancer were the same ( 21 vs 16 stage IIIA – IV NSCLC and extensive stage SCLC , p=0.509 ) . At the end of screening , 61 patients died in the screening group and 42 in the control group ( p=0.059 ) . 15 and 11 died of lung cancer , respectively ( p=0.428 ) . Conclusion CT screening for lung cancer brings forward early disease , and at this point no stage shift or reduction in mortality was observed . More lung cancers were diagnosed in the screening group , indicating some degree of overdiagnosis and need for longer follow-up Background : In  lung cancer CT screening  , participants often have an indeterminate screening result at baseline requiring a follow-up CT . In subjects with either an indeterminate or a negative result after screening , we investigated whether health-related quality of life ( HRQoL ) changed over time and differed between groups in the short term . Methods : A total of 733 participants in the NELSON trial received four question naires : T0 , before r and omisation ; T1 , 1 week before the baseline screening ; T2 , 1 day after the screening ; and T3 , 2 months after the screening results but before the 3-month follow-up CT .  HRQoL was measured as generic HRQoL ( the 12-item Short Form , SF-12 ; the EuroQol question naire , EQ-5D ) , anxiety ( the Spielberger State-Trait Anxiety Inventory , STAI-6 ) , and lung-cancer-specific distress ( the Impact of Event Scale , IES ) . For analyses , repeated- measures analysis of variance was used , adjusted for covariates . Results : Response to each question naire was 88 % or higher . Scores on SF-12 , EQ-5D , and STAI-6 showed no clinical ly relevant changes over time . At T3 , IES scores that were clinical ly relevant increased after an indeterminate result , whereas these scores showed a significant decrease after a negative result . At T3 , differences in IES scores between the two baseline result groups were both significant and clinical ly relevant ( P<0.01 ) . Conclusion : This longitudinal study among participants of a lung cancer screening programme showed that in the short term recipients of an indeterminate result experienced increased lung-cancer-specific distress , whereas the HRQoL changes after a negative baseline screening result may be interpreted as a relief Background : The effect of low-dose CT screening for lung cancer on smoking habits has not been reported in large r and omised controlled trials . Methods : This study evaluated the effect on smoking habits of screening with low-dose CT at 1-year follow up in the Danish Lung Cancer Screening Trial ( DLCST ) , a 5-year r and omised controlled trial comprising 4104 subjects ; 2052 subjects received annual low-dose CT scan ( CT group ) and 2052 received no intervention ( control group ) . Participants were healthy current and former smokers ( > 4 weeks since smoking cessation ) with a tobacco consumption of > 20 pack years .  Smoking habits were determined at baseline and at annual screening . Smoking status was verified using exhaled carbon monoxide levels . Lung function tests , nicotine dependency and motivation to quit smoking were assessed . Quit rates and relapse rates were determined at 1-year follow-up for all subjects . Results : At 1 year the quit rates among smokers were 11.9 % in the CT group and 11.8 % in the control group ( p = 0.95 ) . Relapse rates for former smokers were 10.0 % and 10.5 % in the CT and control groups , respectively ( p = 0.81 ) . Significant predictors ( p<0.05 ) for smoking cessation were : high motivation to quit , low dependency , low ratio of forced expiratory volume in 1 s to forced vital capacity , low pack years , higher age , longer period of abstinence and CT findings necessitating 3-month repeat CT scans . Conclusions : Overall , quit rates were similar in the CT and control group at 1-year follow-up , with a net quit rate of 6.0 % . Quit rates were higher and relapse rate lower among subjects with initial CT findings that necessitated a repeat scan 3 months later BACKGROUND External validation of existing lung cancer risk prediction models is limited . Using such models in clinical practice to guide the referral of patients for computed tomography ( CT ) screening for lung cancer depends on external validation and evidence of predicted clinical benefit . OBJECTIVE To evaluate the discrimination of the Liverpool Lung Project ( LLP ) risk model and demonstrate its predicted benefit for stratifying patients for CT screening  by using data from 3 independent studies from Europe and North America . DESIGN Case-control and prospect i ve cohort study . SETTING Europe and North America . PATIENTS Participants in the European Early Lung Cancer ( EUELC ) and Harvard case-control studies and the LLP population -based prospect i ve cohort ( LLPC ) study . MEASUREMENTS 5-year absolute risks for lung cancer predicted by the  LLP model .  RESULTS The LLP risk model had good discrimination in both the Harvard ( area under the receiver-operating characteristic curve [ AUC ] , 0.76 [ 95 % CI , 0.75 to 0.78 ] ) and the LLPC ( AUC , 0.82 [ CI , 0.80 to 0.85 ] ) studies and modest discrimination in the EUELC ( AUC , 0.67 [ CI , 0.64 to 0.69 ] ) study . The decision utility analysis , which incorporates the harms and benefit of using a risk model to make clinical decisions , indicates that the LLP risk model performed better than smoking duration or family history alone in stratifying high-risk patients for lung cancer CT screening . LIMITATIONS The model can not assess whether including other risk factors , such as lung function or genetic markers , would improve accuracy . Lack of information on asbestos exposure in the LLPC limited the ability to vali date the complete LLP risk model . CONCLUSION Validation of the LLP risk model in 3 independent external data sets demonstrated good discrimination and evidence of predicted benefits for stratifying patients for lung cancer CT screening . Further studies are needed to prospect ively evaluate model performance and evaluate the optimal population risk thresholds for initiating lung cancer screening OBJECTIVE At present , even when early-stage , small-sized non-small cell lung cancers are being increasingly detected , lesser resection has not become the treatment of choice . We sought to compare sublobar resection ( segmentectomy or wedge resection ) with lobar resection to test which one is the appropriate procedure for such lesions . METHODS From 1992 to 2001 , a nonr and omized study was performed in 3 institutes for patients with a peripheral cT1N0M0 non-small cell lung cancer of 2 cm or less who were able to tolerate a lobectomy . The results of the  sublobar resection group  enrolled preoperatively ( n = 305 ) were compared with those of the  lobar resection group ( n = 262 ) . RESULTS Except for distribution of tumor location , there were no significant differences in any variable , patient characteristics , curability , pathologic stage , morbidity , or recurrence rate . Median follow-up was more than 5 years . Disease-free and overall survivals were similar in both groups with 5-year survivals of 85.9 % and 89.6 % for the sublobar resection group and 83.4 % and 89.1 % for the lobar resection group , respectively . Multivariate analysis confirmed that the recurrence rate and prognosis associated with sublobar resection were not inferior to those obtained with lobar resection . Postoperative lung function was significantly better in patients who underwent sublobar resection . CONCLUSIONS Sublobar resection should be considered as an alternative for stage IA non-small cell lung cancers 2 cm or less , even in low-risk patients . These results could lay the foundation for starting r and omized controlled trials anew , which would bring great changes of lung cancer surgery in this era of early detection of lung cancer BACKGROUND The aggressive and heterogeneous nature of lung cancer has thwarted efforts to reduce mortality from this cancer through the use of screening . The advent of low-dose helical computed tomography ( CT ) altered the l and scape of lung-cancer screening , with studies indicating that low-dose CT detects many tumors at early stages . The National Lung Screening Trial ( NLST ) was conducted to determine whether screening with low-dose CT could reduce mortality from lung cancer . METHODS From August 2002 through April 2004 , we enrolled 53,454 persons at high risk for lung cancer at 33 U.S. medical centers . Participants were r and omly assigned to undergo three annual screenings with either low-dose CT ( 26,722 participants ) or single-view posteroanterior chest radiography ( 26,732 ) . Data were collected on cases of lung cancer and deaths from lung cancer that occurred through December 31 , 2009 . RESULTS The rate of adherence to screening was more than 90 % . The rate of positive screening tests was 24.2 % with low-dose CT and 6.9 % with radiography over all three rounds . A total of 96.4 % of the positive screening results in the low-dose CT group and 94.5 % in the radiography group were false positive results . The incidence of lung cancer was 645 cases per 100,000 person-years ( 1060 cancers ) in the low-dose CT group , as compared with 572 cases per 100,000 person-years ( 941 cancers ) in the radiography group ( rate ratio , 1.13 ; 95 % confidence interval [ CI ] , 1.03 to 1.23 ) . There were 247 deaths from lung cancer per 100,000 person-years in the low-dose CT group and 309 deaths per 100,000 person-years in the radiography group , representing a relative reduction in mortality from lung cancer with low-dose CT screening of 20.0 % ( 95 % CI , 6.8 to 26.7 ; P=0.004 ) . The rate of death from any cause was reduced in the low-dose CT group , as compared with the radiography group , by 6.7 % ( 95 % CI , 1.2 to 13.6 ; P=0.02 ) . CONCLUSIONS Screening with the use of low-dose CT reduces mortality from lung cancer . ( Funded by the National Cancer Institute ; National Lung Screening Trial Clinical Trials.gov number , NCT00047385 . ) BACKGROUND The 5-year overall survival rate of lung cancer patients is approximately 15 % . Most patients are diagnosed with advanced-stage disease and have shorter survival rates than patients with early-stage disease . Although screening for lung cancer has the potential to increase early diagnosis , it has not been shown to reduce lung cancer mortality rates . In 1993 , the Prostate , Lung , Colorectal , and Ovarian ( PLCO ) Cancer Screening Trial was initiated specifically to determine whether screening would reduce mortality rates from PLCO cancers . METHODS A total of 77 464 participants , aged 55 - 74 years , were r and omly assigned to the intervention arm of the PLCO Cancer Screening Trial between November 8 , 1993 , and July 2 , 2001 . Participants received a  baseline chest radiograph ( CXR ) , followed by three annual single-view CXRs at the 10 US screening centers . Cancers were classified as screen detected and nonscreen detected ( interval or never screened ) and according to tumor histology . The positivity rates of screen-detected cancers and positive predictive values ( PPVs ) were calculated . Because 51.6 % of the participants were current or former smokers , logistic regression analysis was performed to control for smoking status . All statistical tests were two-sided . RESULTS Compliance with screening decreased from 86.6 % at baseline to 78.9 % at the last screening . Overall positivity rates were 8.9 % at baseline and 6.6%-7.1 % at subsequent screenings ; positivity rates increased modestly with smoking risk categories ( P(trend ) < .001 ) . The PP 
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Harms included radiation exposure , overdiagnosis , and a high rate of false-positive findings that typically were resolved with further imaging .
Smoking cessation was not affected .
Incidental findings were common .
No studies reported results in women or minority population s. CONCLUSION Strong evidence shows that LDCT screening can reduce lung cancer and all-cause mortality .