***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: OBJECTIVE Our objective was to investigate the surgical management of primary lung cancer by board-certified thoracic surgeons participating in the general thoracic surgery portion of The Society of Thoracic Surgeons data base . METHODS We identified all pulmonary resections recorded in the general thoracic surgery prospect i ve data base from 1999 to 2006 . Among the 49,029 recorded operations , 9033 pulmonary resections for primary lung cancer were analyzed . RESULTS There were 4539 men and 4494 women with a median age of 67 years ( range 20 - 94 years ) . Comorbidity affected 79 % of patients and included hypertension in 66 % , coronary artery disease in 26 % , body mass index of 30 kg/m2 or more in 25.7 % , and diabetes mellitus in 13 % . The type of resection was a wedge resection in 1649 ( 18.1 % ) , segmentectomy in 394 ( 4.4 % ) , lobectomy in 6042 ( 67 % ) , bilobectomy in 357 ( 4.0 % ) , and pneumonectomy in 591 ( 6.5 % ) . Mediastinal lymph nodes were evaluated in 5879 ( 65 % ) patients ; via mediastinoscopy in 1928 ( 21 % ) , nodal dissection 3722 ( 41 % ) , nodal sampling in 1124 ( 12.4 % ) , and nodal biopsy in 729 ( 8 % ) . Median length of stay was 5 days ( range 0 - 277 days ) . Operative mortality was 2.5 % ( 179 patients ) . One or more postoperative events occurred in 2911 ( 32 % ) patients . CONCLUSION The patients in the general thoracic surgery data base are elderly , gender balanced , and afflicted by multiple comorbid conditions .  Mediastinal lymph node evaluation is common and the pneumonectomy rate is low . The length of stay is short and operative mortality is low , despite frequent postoperative events CONTEXT Current and former smokers are currently being screened for lung cancer with computed tomography ( CT ) , although there are limited data on the effect screening has on lung cancer outcomes . R and omized controlled trials assessing CT screening are currently under way . OBJECTIVE To assess whether screening may increase the frequency of lung cancer diagnosis and lung cancer resection or may reduce the risk of a diagnosis of advanced lung cancer or death from lung cancer . DESIGN , SETTING , AND PARTICIPANTS Longitudinal analysis of 3246 asymptomatic current or former smokers screened for lung cancer beginning in 1998 either at 1 of 2 academic medical centers in the United States or an academic medical center in Italy with follow-up for a median of 3.9 years . INTERVENTION Annual CT scans with comprehensive evaluation and treatment of detected nodules . MAIN OUTCOME MEASURES Comparison of predicted with observed number of new lung cancer cases , lung cancer resections , advanced lung cancer cases , and deaths from lung cancer . RESULTS There were 144 individuals diagnosed with lung cancer compared with 44.5 expected cases ( relative risk [ RR ] , 3.2 ; 95 % confidence interval [ CI ] , 2.7 - 3.8 ; P<.001 ) . There were 109 individuals who had a lung resection compared with 10.9 expected cases ( RR , 10.0 ; 95 % CI , 8.2 - 11.9 ; P<.001 ) . There was no evidence of a decline in the number of diagnoses of advanced lung cancers ( 42 individuals compared with 33.4 expected cases ) or deaths from lung cancer ( 38 deaths due to lung cancer observed and 38.8 expected ; RR , 1.0 ; 95 % CI , 0.7 - 1.3 ; P = .90 ) . CONCLUSIONS Screening for lung cancer with low-dose CT may increase the rate of lung cancer diagnosis and treatment , but may not meaningfully reduce the risk of advanced lung cancer or death from lung cancer . Until more conclusive data are available , asymptomatic individuals should not be screened outside of clinical research studies that have a reasonable likelihood of further clarifying the potential benefits and risks 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 Two r and omized controlled trials of lung cancer screening initiated in the 1970s , the Johns Hopkins Lung Project and the Memorial Sloan‐Kettering Lung Study , compared 1 arm that received annual chest X‐ray and 4‐monthly sputum cytology ( dual‐screen ) to a second arm that received annual chest X‐ray only . Previous publications from these trials reported similar lung cancer mortality between the 2 groups . However , these findings were based on incomplete follow‐up , and each trial on its own was underpowered to detect a modest mortality benefit BACKGROUND The use of multidetector computed tomography ( CT ) in lung-cancer screening trials involving subjects with an increased risk of lung cancer has highlighted the problem for the clinician of deciding on the best course of action when noncalcified pulmonary nodules are detected by CT . METHODS A total of 7557 participants underwent CT screening in years 1 , 2 , and 4 of a r and omized trial of lung-cancer screening . We used software to evaluate a noncalcified nodule according to its volume or volume-doubling time . Growth was defined as an increase in volume of at least 25 % between two scans . The first-round screening test was considered to be negative if the volume of a nodule was less than 50 mm(3 ) , if it was 50 to 500 mm(3 ) but had not grown by the time of the 3-month follow-up CT , or if , in the case of those that had grown , the volume-doubling time was 400 days or more . RESULTS In the first and second rounds of screening , 2.6 % and 1.8 % of the participants , respectively , had a positive test result . In round one , the sensitivity of the screen was 94.6 % ( 95 % confidence interval [ CI ] , 86.5 to 98.0 ) and the negative predictive value 99.9 % ( 95 % CI , 99.9 to 100.0 ) . In the 7361 subjects with a negative screening result in round one , 20 lung cancers were detected after 2 years of follow-up . CONCLUSIONS Among subjects at high risk for lung cancer who were screened in three rounds of CT scanning and in whom noncalcified pulmonary nodules were evaluated according to volume and volume-doubling time , the chances of finding lung cancer 1 and 2 years after a negative first-round test were 1 in 1000 and 3 in 1000 , respectively . ( Current Controlled Trials number , IS RCT N63545820 . 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 The Memorial Sloan-Kettering lung cancer screening program was begun in 1974 to evaluate sputum cytology as a supplement to the annual chest x-ray examination for early detection and diagnosis . The 10,040 adult , male cigarette smokers who enrolled were r and omly assigned to receive annual chest x-ray examinations only or a dual screen with annual chest x-ray examination and four monthly sputum cytology evaluation . Over 40 percent of the 288 who developed lung cancer were diagnosed in stage I , and their survival was 76 percent at five years ; overall survival was 35 percent . Nearly one third of the lung cancers detected on first examination on the dual screen , and 14 percent of those on subsequent examinations were found by cytologic examination . The same number of cancers developed in the x-ray screen only group , and were diagnosed at a later date . Despite the delay , survival and mortality were the same , suggesting that the squamous carcinomas detected by cyt 
    Output:
    
Conclusions : Screening is a complex interplay of selection ( a population with suffi cient risk and few serious comorbidities ) , the value of the screening test , the interval between screening tests , the availability of effective treatment , the risk of complications or harms as a result of screening , and the degree with which the screened individuals comply with screening and treatment recommendations .
Screening with LDCT of appropriate individuals in the context of a structured process is associated with a signifi ca nt reduction in the number of lung cancer deaths in the screened population .