***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 . PURPOSE Epidermal growth factor receptor ( EGFR ) mutations have been associated with tumor response to treatment with single-agent EGFR inhibitors in patients with relapsed non-small-cell lung cancer ( NSCLC ) . The implication s of EGFR mutations in patients treated with EGFR inhibitors plus first-line chemotherapy are unknown . KRAS is frequently activated in NSCLC . The relationship of KRAS mutations to outcome after EGFR inhibitor treatment has not been described . PATIENTS AND METHODS Previously untreated patients with advanced NSCLC in the phase III TRIBUTE study who were r and omly assigned to carboplatin and paclitaxel with erlotinib or placebo  were assessed for survival , response , and time to progression ( TTP ) . EGFR exons 18 through 21 and KRAS exon 2 were sequenced in tumors from 274 patients . Outcomes were correlated with EGFR and KRAS mutations in retrospective subset analyses . RESULTS EGFR mutations were detected in 13 % of tumors and were associated with longer survival , irrespective of treatment ( P < .001 ) . Among erlotinib-treated patients , EGFR mutations were associated with improved response rate ( P < .05 ) and there was a trend toward an erlotinib benefit on TTP ( P = .092 ) , but not improved survival ( P = .96 ) . KRAS mutations ( 21 % of tumors ) were associated with significantly decreased TTP and survival in erlotinib plus chemotherapy-treated patients . CONCLUSION EGFR mutations may be a positive prognostic factor for survival in advanced NSCLC patients treated with chemotherapy with or without erlotinib , and may predict greater likelihood of response . Patients with KRAS-mutant NSCLC showed poorer clinical outcomes when treated with erlotinib and chemotherapy . Further studies are needed to confirm the findings of this retrospective subset analysis PURPOSE This study attempted to determine the prognostic value for survival of various pretreatment characteristics in patients with nonresectable non-small-cell lung cancer in the context of more than 10 years of experience of a European Cooperative Group . PATIENTS AND METHODS We included in the analysis all eligible patients ( N = 1,052 ) with advanced non-small-cell lung cancer registered onto one of seven trials conducted by the European Lung Cancer Working Party ( ELCWP ) during one decade . The patients were treated by chemotherapy regimens based on platinum derivatives . We prospect ively collected 23 variables and analyzed them by univariate and multivariate methods . RESULTS The global estimated median survival time was 29 weeks , with a 95 % confidence interval of 27 to 30 weeks . After univariate analysis , we applied two multivariate statistical techniques . In a Cox regression model , the selected explanatory variables were disease extent , Karnofsky performance status , WBC and neutrophil counts , metastatic involvement of skin , serum calcium level , age , and sex . These results were confirmed by application of recursive partitioning and amalgamation algorithms ( RECPAM ) , which led to classification of the patients into four homogeneous subgroups . CONCLUSION We confirmed by our analysis the role of well-known independent prognostic factors for survival , but also identified the effect of the neutrophil count , rarely studied , with the use of two methods : a classical Cox regression model and a RECPAM analysis . The classification of patients into the four subgroups we obtained needs to be vali date d in other series BACKGROUND This study prospect ively assessed the efficacy of gefitinib and the survival benefit for non-small cell lung cancer ( NSCLC ) patients with epidermal growth factor receptor ( EGFR ) mutations . METHOD Patients with either recurrent disease after undergoing surgery or advanced NSCLC disease ( IIIB or IV ) which demonstrated EGFR mutations were eligible for this study . EGFR mutations in exons 19 - 21 were examined . The patients with EGFR mutations were enrolled in this study after obtaining their informed consent a second time , and they were thereafter treated with gefitinib . RESULTS EGFR mutations were detected in 20 of 48 patients with NSCLC , and 19 patients were enrolled onto this study and treated with gefitinib . Seven patients had an exon 19 deletion , 10 had L858R , 1 had both , and 1 had an exon 19 deletion and G796A . The overall response rate was 63.2 % , and the disease control rate was 89.5 % . In patients with an exon 19 del and L858R , the response rates were 71.4 % and 60.0 % , respectively . The median progression-free survival time was 7.1 months , and the median survival time was 20.0 months . No life-threatening toxicity was observed . Four of five acquired resistant tumors showed an acquired T790 M mutation . CONCLUSIONS EGFR mutations in exons 19 or 21 are considered to be a good predictor of the efficacy of gefitinib 
    Output:
    
The subgroup analysis based on univariate and multivariate analyses in DFS and OS showed no statistically significant difference .
There was also no statistically significant difference in DFS and OS of stage I NSCLC patients .
The systematic review with meta- analysis showed that EGFR mutations were not a prognostic factor in patients with surgically resected non-small cell lung cancer .