***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 Previous , uncontrolled studies have suggested that first-line treatment with gefitinib would be efficacious in selected patients with non-small-cell lung cancer . METHODS In this phase 3 , open-label study , we r and omly assigned previously untreated patients in East Asia who had advanced pulmonary adenocarcinoma and who were nonsmokers or former light smokers to receive gefitinib ( 250 mg per day ) ( 609 patients ) or carboplatin ( at a dose calculated to produce an area under the curve of 5 or 6 mg per milliliter per minute ) plus paclitaxel ( 200 mg per square meter of body-surface area ) ( 608 patients ) . The primary end point was progression-free survival . RESULTS The 12-month rates of progression-free survival were 24.9 % with gefitinib and 6.7 % with carboplatin-paclitaxel . The study met its primary objective of showing the noninferiority of gefitinib and also showed its superiority , as compared with carboplatin-paclitaxel , with respect to progression-free survival in the intention-to-treat population ( hazard ratio for progression or death , 0.74 ; 95 % confidence interval [ CI ] , 0.65 to 0.85 ; P<0.001 ) . In the subgroup of 261 patients who were positive for the epidermal growth factor receptor gene ( EGFR ) mutation , progression-free survival was significantly longer among those who received gefitinib than among those who received carboplatin-paclitaxel ( hazard ratio for progression or death , 0.48 ; 95 % CI , 0.36 to 0.64 ; P<0.001 ) , whereas in the subgroup of 176 patients who were negative for the mutation , progression-free survival was significantly longer among those who received carboplatin-paclitaxel ( hazard ratio for progression or death with gefitinib , 2.85 ; 95 % CI , 2.05 to 3.98 ; P<0.001 ) . The most common adverse events were rash or acne ( in 66.2 % of patients ) and diarrhea ( 46.6 % ) in the gefitinib group and neurotoxic effects ( 69.9 % ) , neutropenia ( 67.1 % ) , and alopecia ( 58.4 % ) in the carboplatin-paclitaxel group . CONCLUSIONS Gefitinib is superior to carboplatin-paclitaxel as an initial treatment for pulmonary adenocarcinoma among nonsmokers or former light smokers in East Asia . The presence in the tumor of a mutation of the EGFR gene is a strong predictor of a better outcome with gefitinib . ( Clinical Trials.gov number , NCT00322452 . BACKGROUND Activating mutations in EGFR are important markers of response to tyrosine kinase inhibitor ( TKI ) therapy in non-small-cell lung cancer ( NSCLC ) . The OPTIMAL study compared efficacy and tolerability of the TKI erlotinib versus st and ard chemotherapy in the first-line treatment of patients with advanced EGFR mutation-positive NSCLC . METHODS We undertook an open-label , r and omised , phase 3 trial at 22 centres in China . Patients older than 18 years with histologically confirmed stage IIIB or IV NSCLC and a confirmed activating mutation of EGFR ( exon 19 deletion or exon 21 L858R point mutation ) received either oral erlotinib ( 150 mg/day ) until disease progression or unacceptable toxic effects , or up to four cycles of gemcitabine plus carboplatin . Patients were r and omly assigned ( 1:1 ) with a minimisation procedure and were stratified according to EGFR mutation type , histological subtype ( adenocarcinoma vs non-adenocarcinoma ) , and smoking status . The primary outcome was progression-free survival , analysed in patients with confirmed disease who received at least one dose of study treatment . The trial is registered at Clinical Trials.gov , number NCT00874419 , and has completed enrolment ; patients are still in follow-up . FINDINGS 83 patients were r and omly assigned to receive erlotinib and 82 to receive gemcitabine plus carboplatin ; 82 in the erlotinib  group and 72 in the  chemotherapy group were included in analysis of the primary endpoint . Median progression-free survival was significantly longer in erlotinib-treated patients than in those on chemotherapy ( 13.1 [ 95 % CI 10.58 - 16.53 ] vs 4.6 [ 4.21 - 5.42 ] months ; hazard ratio 0.16 , 95 % CI 0.10 - 0.26 ; p<0.0001 ) . Chemotherapy was associated with more grade 3 or 4 toxic effects than was erlotinib ( including neutropenia in 30 [ 42 % ] of 72 patients and thrombocytopenia in 29 [ 40 % ] patients on chemotherapy vs no patients with either event on erlotinib ) ; the most common grade 3 or 4 toxic effects with erlotinib were increased alanine aminotransferase concentrations ( three [ 4 % ] of 83 patients ) and skin rash ( two [ 2 % ] patients ) . Chemotherapy was also associated with increased treatment-related serious adverse events ( ten [ 14 % ] of 72 patients [ decreased platelet count , n=8 ; decreased neutrophil count , n=1 ; hepatic dysfunction , n=1 ] vs two [ 2 % ] of 83 patients [ both hepatic dysfunction ] ) . INTERPRETATION Compared with st and ard chemotherapy , erlotinib conferred a significant progression-free survival benefit in patients with advanced EGFR mutation-positive NSCLC and was associated with more favourable tolerability . These findings suggest that erlotinib is important for first-line treatment of patients with advanced EGFR mutation-positive NSCLC . FUNDING F Hoffmann-La Roche Ltd ( China ) ; Science and Technology Commission of Shanghai Municipality PURPOSE The phase III Iressa Survival Evaluation in Lung Cancer ( ISEL ) trial compared gefitinib with placebo in 1,692 patients with refractory advanced non-small-cell lung cancer . We analyzed ISEL tumor biopsy sample s to examine relationships between biomarkers and clinical outcome after gefitinib treatment in a placebo-controlled setting . METHODS Biomarkers included epidermal growth factor receptor ( EGFR ) gene copy number by fluorescence in situ hybridization ( n = 370 ) ; EGFR ( n = 379 ) and phosphorylated Akt ( p-Akt ) protein expression ( n = 382 ) by immunohistochemistry ; and mutations in EGFR ( n = 215 ) , KRAS ( n = 152 ) , and BRAF ( n = 118 ) . RESULTS High EGFR gene copy number was a predictor of a gefitinib-related effect on survival ( hazard ratio [ HR ] , 0.61 for high copy number and HR , 1.16 for low copy number ; comparison of high v low copy number HR , P = .045 ) . EGFR protein expression was also related to clinical outcome ( HR for positive , 0.77 ; HR for negative , 1.57 ; comparison of high v low protein expression HR , P = .049 ) . Patients with EGFR mutations had higher response rates than patients without EGFR mutations ( 37.5 % v 2.6 % ) ; there were insufficient data for survival analysis . No relationship was observed between p-Akt protein expression and survival outcome , and the limited amount of data collected for KRAS and BRAF mutations prevented any meaningful evaluation of clinical outcomes in relation to these mutations . CONCLUSION EGFR gene copy number was a predictor of clinical benefit from gefitinib in ISEL . Additional studies are warranted to assess these biomarkers fully for the identification of patients most likely to benefit from gefitinib treatment Diagnosis is a critical component of health care , and clinicians , policymakers , and patients routinely face a range of questions regarding diagnostic tests . They want to know whether testing improves outcome ; what test to use , purchase , or recommend in practice guidelines ; and how to interpret test results . Well- design ed  diagnostic test accuracy studies can help in making these decisions , provided that they transparently and fully report their participants , tests , methods , and results as facilitated , for example , by the STARD ( St and ards for Reporting of Diagnostic Accuracy ) statement ( 1 ) . That 25-item checklist was published in many journals and is now adopted by more than 200 scientific journals worldwide . As in other areas of science , systematic review s and meta- analysis of accuracy studies can be used to obtain more precise estimates when small studies addressing the same test and patients in the same setting are available . Review s can also be useful to establish whether and how scientific findings vary by particular subgroups , and may provide summary estimates with a stronger generalizability than estimates from a single study . Systematic review s may help identify the risk for bias that may be present in the original studies and can be used to address questions that were not directly considered in the primary studies , such as comparisons between tests . The Cochrane Collaboration is the largest international organization preparing , maintaining , and promoting systematic review s to help people make well-informed decisions about health care ( 2 ) . The Collaboration decided in 2003 to make preparations for including systematic review s of diagnostic test accuracy in their Cochrane Data base of Systematic Review s. To enable this , a working group ( Appendix ) . was formed to develop methodology , software , and a h and book The first diagnostic test accuracy review was published in the Cochrane Data base in October 2008 . In this paper , we review recent method ological developments concerning problem formulation , location of literature , quality assessment , and meta- analysis of diagnostic accuracy studies by using our experience from the work on the Cochrane H and book . The information presented here is based on the recent literature and up date s previously published guidelines by Irwig and colleagues ( 3 ) . Definition of the Objectives of the Review Diagnostic test accuracy refers to the ability of a test to distinguish between patients with disease ( or more generally , a specified target condition ) and those without . In a study of test accuracy , the results of the test under evaluation , the index test , are compared with those of the reference st and ard determined in the same patients . The reference st and ard is an agreed-on and accurate method for identifying patients who have the target condition . Test results are typically categorized as positive or negative for the target condition . By using such binary test outcomes , the accuracy is most often expressed as the test 's sensitivity ( the proportion of patients with positive results on the reference st and ard that are also positive on the index test ) and specificity ( the proportion of patients with negative results on the reference st and ard that are also negative on the index test ) . Other measures have been proposed and are in use ( 46 ) . It has long been recognized that test accuracy is not a fixed property of a test . It can vary between patient subgroups , with their spectrum of disease , with the clinical setting , or with the test interpreters and may depend on the results of previous testing . For this reason , inclusion of these elements in the study question is essential . In order to make a policy decision to promote use of a new index test , evidence is required that using the new test increases test accuracy over other testing options , including current practice , or that the new test has equivalent accuracy but offers other advantages ( 79 ) . As with the evaluation of interventions , systematic review s need to include comparative analyses between alternative testing strategies and should not focus solely on evaluating the performance of a test in isolation . In relation to the existing situation , 3 possible roles for a new test can be defined : replacement , triage , and add-on ( 7 ) . If a new test is to replace an existing test , then comparing the accuracy of both tests on the same population and with the same reference st and ard provides the most direct evidence . In triage , the new test is used before the existing test or testing pathway , and only patients with a particular result on the triage test continue the testing pathway . When a test is needed to rule out disease in patients who then need no further testing , a test that gives a minimal proportion of falsenegative results and thus a relatively high sensitivity should be used . Triage tests may be less accurate than existing ones , but they have other advantages , such as simplicity or low cost . A third possible role of a new test is add-on . The new test is then positioned after the existing testing pathway to identify false-positive or false-negative results after the existing pathway . The review should provide data to assess the incremental change in accuracy made by adding the new test . An example of a replacement question can be found in a systematic review of the diagnostic accuracy of urinary markers for primary bladder cancer ( 10 ) . Clinicians may use cytology to triage patients before they undergo invasive cystoscopy  , the reference st and ard for bladder cancer . Because cytology combines high specificity with low sensitivity ( 11 ) , the goal of the review was to identify a tumor marker with sufficient accuracy to either replace cytology or be used in addition to cytology . For a marker to replace cytology , it has to achieve equally high specificity with improved sensitivity . New markers that are sensitive but not specific may have roles as adjuncts to conventional testing . The review included studies in which the test under evaluation ( several different tumor markers and cytology ) was evaluated against cystoscopy or histopathology . Included studies compared 1 or more of the markers , cytology only , or a combination of markers and cytology . Although information on accuracy can help clinicians make decisions about tests , good diagnostic accuracy is a desirable but not sufficient condition for the effectiveness of a test ( 8) . To demonstrate that using a new 
    Output:
    
The meta- analysis suggests that detection of EGFR mutation by cfDNA is of adequate diagnostic accuracy and cfDNA analysis could be a promising screening test for NSCLC