***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 The objectives of the Prostate , Lung , Colorectal and Ovarian Cancer Screening Trial are to determine in screenees ages 55 - 74 at entry whether screening with flexible sigmoidoscopy ( 60-cm sigmoidoscope ) can reduce mortality from colorectal cancer , whether screening with chest X-ray can reduce mortality from lung cancer , whether screening men with digital rectal examination ( DRE ) plus serum prostate-specific antigen ( PSA ) can reduce mortality from prostate cancer , and whether screening women with CA125 and transvaginal ultrasound ( TVU ) can reduce mortality from ovarian cancer . Secondary objectives are to assess screening variables other than mortality for each of the interventions including sensitivity , specificity , and positive predictive value ; to assess incidence , stage , and survival of cancer cases ; and to investigate biologic and /or prognostic characterizations of tumor tissue and biochemical products as intermediate endpoints . The design is a multicenter , two-armed , r and omized trial with 37,000 females and 37,000 males in each of the two arms . In the intervention arm , the  PSA and CA125 tests  are performed at entry , then annually for 5 years . The  DRE , TVU , and chest X-ray exams  are performed at entry and then annually for 3 years . Sigmoidoscopy is performed at entry and then at the 5-year point . Participants in the control arm follow their usual medical care practice s. Participants will be followed for at least 13 years from r and omization to ascertain all cancers of the prostate , lung , colorectum , and ovary , as well as deaths from all causes . A pilot phase was undertaken to assess the r and omization , screening , and data collection procedures of the trial and to estimate design parameters such as compliance and contamination levels . This paper describes eligibility , consent , and other design features of the trial , r and omization and screening procedures , and an outline of the follow-up procedures . Sample -size calculations are reported , and a data analysis plan is presented BACKGROUND Results of r and omized clinical trials ( RCTs ) are needed to assess the efficacy of lung cancer screening with low-dose chest computed tomography ( CT ) in reducing lung cancer mortality . We report design and results of enrolment and baseline screening test in the ITALUNG trial , a RCT . METHODS Invitation letters were sent to subjects of 55 - 69 years of age clients of 269 general practitioners . Smokers or former smokers of at least 20 pack/years were eligible and after written consent were r and omized in an active arm undergoing a low-dose CT annually for 4 years and in a control arm receiving no screening . Management of positive screening test was carried out using follow-up low-dose CT , fluorodeoxyglucose positron emission tomography , fine needle aspiration cytology and fiber optic bronchoscopy . RESULTS A sample of 3206 eligible subjects was achieved by sending 71,232 letters ( enrolment efficacy = 4.5 % ) . Subjects in control ( n = 1593 ) and active ( n = 1613 ) arm were balanced for age , gender and smoking history . Two-hundred and seven ( 12.8 % ) subjects did not undergo CT after r and omization . The baseline screening test was positive in 426 ( 30.3 % ) of 1406 subjects . Twenty-one lung cancers ( prevalence = 1.5 % ) were found in 20 subjects : 18 non-small cell lung cancer ( NSCLC ) , 2 small cell lung cancer ( SCLC ) and a case of typical carcinoid . Ten NSCLC ( 47.6 % ) were in Stage I. Sixteen fine needle aspirations were performed in 15 lung cancers , with a positive result in 12 ( 75 % ) cases . One biopsy only ( 6.3 % ) was performed on a benign lesion . Seventeen lung cancers ( 81 % ) were treated with surgical resection in 16 subjects . One subject underwent surgery for a benign lesion ( 5.5 % of all surgical resections ) . CONCLUSIONS Recruitment by mail of high risk subjects for a lung cancer screening RCT is feasible but not efficient . Results of the baseline screening test in the active arm of the ITALUNG trial are substantially in line with those of RCT and observational studies Results are reported of a prospect i ve study , carried out by the  Mass Radiography Service of the North-West Metropolitan Region for the purpose of evaluating early lung cancer detection by six-monthly chest radiographs . The lung cancer experience of a test group of 29,723 men aged 40 and over who were offered six-monthly chest radiographs over a period of three years is compared with a similarly constituted control group of 25,311 men who were radiographed only at the beginning and the end of the study . In the test group 29,416 men ( 98·9 % ) and in the control group 25,044 men ( 99 % ) were followed up . The methods employed to achieve this result are analysed . The six-monthly surveys of the test group yielded 65 cases of lung cancer , giving an annual incidence and detection rate of 0·9 per thous and examined . Of these cases 65 % were resected . Of all cases of lung cancer in the test group , irrespective of their source of detection , 43·6 % were operable , compared with 29 % in the control group . The difference ( P=0·03 ) is statistically significant . The annual mortality rate from lung cancer based on 62 deaths in the test group and 59 deaths in the control was 0·7 and 0·8 per thous and respectively . The conclusions are reached that since early detection by six-monthly chest radiographs has not significantly reduced the mortality from lung cancer in a population at risk , a policy of such large-scale surveys of men in the cancer age would not seem justified , but that the increased discovery of resectable lung cancer by this method forms a reasonable basis for encouraging individuals in high-risk groups to make regular use of existing mass radiography facilities Survival of patients with lung carcinoma is very poor , particularly for patients with advanced disease . There are no early clinical symptoms , and screening with chest radiography has not been recommended . Computed tomography ( CT ) is superior to radiography for detection of pulmonary nodules but usually is associated with relatively high radiation exposure . Recently , accuracy of low dose CT has been shown to be similar to conventional dose CT . The goal of the current study was to assess the findings of low dose CT of the chest in heavy smokers 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 The aim of this study was analysis of incidence results in a prospect i ve one-arm feasibility study of lung cancer screening with low-radiation-dose spiral computed tomography in heavy smokers . Eight hundred seventeen smokers ( ≥40 years , ≥20 pack years of smoking history ) underwent baseline low-dose CT . Biopsy was recommended in nodules > 10 mm with CT morphology suggesting malignancy . In all other lesions follow-up with low-dose CT was recommended . Annual repeat CT was offered to all study participants . Six hundred sixty-eight ( 81.8 % ) of the 817 subjects underwent annual repeat CT  with a total of 1735 follow-up years . Follow-up of non-calcified nodules present at baseline CT demonstrated growth in 11 of 792 subjects . Biopsy was performed in 8 of 11 growing nodules 7 of which represented lung cancer . Of 174 new nodules , 3 represented lung cancer . The 10 screen-detected lung cancers were all non-small cell cancer ( 6 stage IA , 1 stage IB , 1 stage IIIA , 2 stage IV ) . Five symptom-diagnosed cancers ( 2 small cell lung cancer : 1 limited disease , 1 extensive disease , 3 central /endobronchial non-small cell lung cancer , 2 stage IIIA , 1 stage IIIB ) were diagnosed because of symptoms in the 12-month interval between two annual CT scans . Incidence of lung cancer was lower than prevalence , screen-detected cancers were smaller , and stage I was found in 70 % ( 7 of 10 ) of screen-detected tumors . Only 27 % ( 4 of 15 ) of invasive procedures was performed for benign lesions ; however , 33 % ( 5 of 15 ) of all cancers diagnosed in the population were symptom-diagnosed cancers ( 3 central NSCLC , all stage III , 2 SCLC ) demonstrating the limitations of CT screening BACKGROUND Low-dose spiral CT of the chest effectively detects early-stage  lung cancer in high-risk individuals . The high rate of benign nodules and issues of making a differential diagnosis are critical factors that currently hamper introduction of large-scale screening programmes . We investigated the efficacy of repeated yearly spiral CT and selective use of positron emission tomography ( PET ) in a large cohort of high-risk volunteers . METHODS We enrolled 1035 individuals aged 50 years or older who had smoked for 20 pack-years or more . All patients underwent annual low-dose CT , with or without PET , for 5 years . Lesions up to 5 mm were deemed non-suspicious and low-dose CT was repeated after 12 months ( year 2 ) . FINDINGS By year 2 , 22 cases of lung cancer had been diagnosed ( 11 at baseline , 11 at year 2 ) . 440 lung lesions were identified in 298 ( 29 % ) participants , and 95 were recalled for high-resolution contrast CT . PET scans were positive in 18 of 20 of the identified cancer cases . Six patients underwent surgical biopsy for benign disease because of false-positive results ( 6 % of recalls , 22 % of invasive procedures ) . Complete resection was achieved in 21 ( 95 % ) lung cancers , 17 
    Output:
    
Major complications in those with benign conditions were rare .