***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: Are meta-analyses the brave new world , or are the critics of such combined analyses right to say that the biases inherent in clinical trials make them uncombinable ? Negative trials are often unreported , and hence can be missed by meta-analysts . And how much heterogeneity between trials is acceptable ? A recent major criticism is that large r and omised trials do not always agree with a prior meta- analysis . Neither individual trials nor meta-analyses , reporting as they do on population effects , tell how to treat the individual patient . Here we take a more rounded approach to meta-analyses , arguing that their strengths outweigh their weaknesses , although the latter must not be brushed aside BACKGROUND We undertook to determine whether adjuvant vinorelbine plus cisplatin prolongs overall survival among patients with completely resected early-stage non-small-cell lung cancer . METHODS We r and omly assigned patients with completely resected stage IB or stage II non-small-cell lung cancer to vinorelbine plus cisplatin or to observation . The primary end point was overall survival ; principal secondary end points were recurrence-free survival and the toxicity and safety of the regimen . RESULTS A total of 482 patients underwent r and omization to vinorelbine plus cisplatin ( 242 patients ) or observation ( 240 ) ; 45 percent of the patients had pathological stage IB disease and 55 percent had stage II , and all had an Eastern Cooperative Oncology Group performance status score of 0 or 1 . In both groups , the median age was 61 years , 65 percent were men , and 53 percent had adenocarcinomas . Chemotherapy caused neutropenia in 88 percent of patients ( including grade 3 febrile neutropenia in 7 percent ) and death from toxic effects in two patients ( 0.8 percent ) . Nonhematologic toxic effects of chemotherapy were fatigue ( 81 percent of patients ) , nausea ( 80 percent ) , anorexia ( 55 percent ) , vomiting ( 48 percent ) , neuropathy ( 48 percent ) , and constipation ( 47 percent ) , but severe ( grade 3 or greater ) toxic effects were uncommon ( < 10 percent ) . Overall survival was significantly prolonged in the chemotherapy group as compared with the observation group ( 94 vs. 73 months ; hazard ratio for death , 0.69 ; P=0.04 ) , as was relapse-free survival ( not reached vs. 46.7 months ; hazard ratio for recurrence , 0.60 ; P<0.001 ) . Five-year survival rates were 69 percent and 54 percent , respectively ( P=0.03 ) . CONCLUSIONS Adjuvant vinorelbine plus cisplatin has an acceptable level of toxicity and prolongs disease-free and overall survival among patients with completely resected early-stage non-small-cell lung cancer BACKGROUND On the basis of a previous meta- analysis , the International Adjuvant Lung Cancer Trial was design ed to evaluate the effect of cisplatin-based adjuvant chemotherapy on survival after complete resection of non-small-cell lung cancer . METHODS We r and omly assigned patients either to three or four cycles of cisplatin-based chemotherapy or to observation . Before r and omization , each center determined the pathological stages to include , its policy for chemotherapy ( the dose of cisplatin and the drug to be combined with cisplatin ) , and its postoperative radiotherapy policy . The main end point was overall survival . RESULTS A total of 1867 patients underwent r and omization ; 36.5 percent had pathological stage I disease , 24.2 percent stage II , and 39.3 percent stage III . The drug allocated with cisplatin was etoposide in 56.5 percent of patients , vinorelbine in 26.8 percent , vinblastine in 11.0 percent , and vindesine in 5.8 percent . Of the 932 patients assigned to chemotherapy , 73.8 percent received at least 240 mg of cisplatin per square meter of body-surface area . The median duration of follow-up was 56 months . Patients assigned to chemotherapy had a significantly higher survival rate than those assigned to observation ( 44.5 percent vs. 40.4 percent at five years [ 469 deaths vs. 504 ] ; hazard ratio for death , 0.86 ; 95 percent confidence interval , 0.76 to 0.98 ; P<0.03 ) . Patients assigned to chemotherapy also had a significantly higher disease-free survival rate than those assigned to observation ( 39.4 percent vs. 34.3 percent at five years [ 518 events vs. 577 ] ; hazard ratio , 0.83 ; 95 percent confidence interval , 0.74 to 0.94 ; P<0.003 ) . There were no significant interactions with prespecified factors . Seven patients ( 0.8 percent ) died of chemotherapy-induced toxic effects . CONCLUSIONS Cisplatin-based adjuvant chemotherapy improves survival among patients with completely resected non-small-cell lung cancer BACKGROUND Little prospect i ve , multiinstitutional data exist regarding the morbidity and mortality after major pulmonary resections for lung cancer or whether a mediastinal lymph node dissection increases morbidity and mortality . METHODS Prospect ively collected 30-day postoperative data was analyzed from 1,111 patients undergoing pulmonary resection who were enrolled from July 1999 to February 2004 in a r and omized trial comparing lymph node sampling versus mediastinal lymph node dissection for early stage lung cancer . RESULTS Of the 1,111 patients r and omized , 1,023 were included in the analysis . Median age was 68 years ( range , 23 to 89 years ) ; 52 % were men . Lobectomy was performed in 766 ( 75 % ) and pneumonectomy in 42 ( 4 % ) . Pathologic stage was IA in 424 ( 42 % ) , IB in 418 ( 41 % ) , IIA in 37 ( 4 % ) , IIB in 97 ( 9 % ) , and III in 45 ( 5 % ) . Lymph node sampling was performed in 498 patients and lymph node dissection in 525 . Operative mortality was 2.0 % ( 10 of 498 ) for lymph node sampling and 0.76 % ( 4 of 525 ) for lymph node dissection . Complications occurred in 38 % of patients in each group . Lymph node dissection had a longer median operative time and greater total chest tube drainage ( 15 minutes , 121 mL , respectively ) . There was no difference in the median hospitalization , which was 6 days in each group ( p = 0.404 ) . CONCLUSIONS Complete mediastinal lymphadenectomy adds little morbidity to a pulmonary resection for lung cancer . These data from a current , multiinstitutional cohort of patients who underwent a major pulmonary resection constitute a new baseline with which to compare results in the future BACKGROUND Mediastinal lymph node dissection ( MLND ) is an integral part of surgery for non-small cell lung cancer ( NSCLC ) . To compare the impact of systematic sampling ( SS ) and complete MLND on the identification of mediastinal lymph node metastases and patient survival , the Eastern Cooperative Oncology Group ( ECOG ) stratified patients by type of MLND before participation in ECOG 3590 ( a r and omized prospect i ve trial of  adjuvant therapy in patients with completely resected stages II and IIIa NSCLC ) . METHODS Eligibility requirements for study entry included a thorough investigation of the mediastinal lymph nodes with either SS or complete MLND . The former was defined as removal of at least one lymph node at levels 4 , 7 , and 10 during a right thoracotomy and at levels 5 and /or 6 and 7 during a left thoracotomy , while the latter required complete removal of all lymph nodes at those levels . RESULTS Three hundred seventy-three eligible patients were accrued to the study . Among the 187 patients who underwent SS  , N1 disease was identified in 40 % and N2 disease in 60 % . This was not significantly different than the 41 % of N1 disease and 59 % of N2 disease found among the 186 patients who underwent complete MLND . Among the 222 patients with N2 metastases , multiple levels of N2 disease were documented in 30 % of patients who underwent complete MLND and in 12 % of patients who had SS ( p = 0.001 ) . Median survival was 57.5 months for those patients who had undergone complete MLND and 29.2 months for those patients who had SS ( p = 0.004 ) . However , the survival advantage was limited to patients with right lung tumors ( 66.4 months vs 24.5 months , p<0.001 ) . CONCLUSIONS In this nonr and omized comparison , SS was as efficacious as complete MLND in staging patients with NSCLC . However , complete MLND identified significantly more levels of N2 disease . Furthermore , complete MLND was associated with improved survival with right NSCLC when compared with SS PURPOSE We conducted a r and omized trial to investigate whether systematic nodal dissection ( SND ) is superior to mediastinal lymph nodal sampling ( MLS ) in surgical treatment of non-small cell lung cancer ( NSCLC ) . METHODS The patients resectable clinical Stage I-IIIA NSCLC were r and omly assigned to lung resection combined with SND or lung resection combined with MLS . After postoperative pathological re-staging , eligible cases were followed up until 30 November 2000 . The Kaplan-Meier method was used for survival analysis . COX proportional hazards model was used for prognostic analysis . RESULTS Of the 532 patients who were enrolled in the study , 268 patients were assigned to lung resection combined with SND and 264 were assigned to lung resection combined with MLS . After surgical restaging only 471 cases were eligible for follow-up . The median survival was 59 months in the group given SND and 34 months in the group given MLS ( P=0.0000 by the log rank test ) . There was significant difference in survival in Stage I ( 5-year survival 82.16 vs. 57.49 % ) and Stage IIIA ( 26.98 vs. 6.18 % ) by the log rank test and Breslow test . There was no significant yet marginal difference in survival by log rank test ( 10-year survival 32.04 vs. 26.92 % , P=0.0523 ) but significant difference in survival by Breslow test ( 5-year survival 50.42 vs. 34.05 % , P=0.0284 ) in Stage II . Types of mediastinal lymph node dissection , pTNM stage , tumor size and number of lymph node metastasis were four factors that influenced long-term survival rate by multivariate analysis . CONCLUSIONS As compared with MLS , lobectomy ( pneumonectomy ) combined with SND can improve survival in resectable NSCLC Abstract . The value of radical systematic lymphadenectomy for treatment of early-stage bronchial carcinoma is controversial . We performed a prospect i ve r and omized study to address this question . Altogether 115 patients with peripheral non-small-cell lung cancers smaller than 2 cm in diameter were enrolled in this study . They were r and omly assigned into a lobectomy with lymph node sampling group ( sampling group , n= 56 ) or a lobectomy with radical systematic lymph node dissection group ( dissection group , n= 59 ) . Inclusion criteria were based only on preoperative clinical studies . Four tumors were larger than 2 cm postoperatively . One patient had disseminated disease , and two had intrapulmonary metastases discovered at surgery . Two patients had small-cell carcinoma . There were four with pathologic N1 disease and seven with N2 disease in the dissection group and three with N1 and eight with N2 disease in the sampling group . The numbers of local and distant recurrences were two and six , respectively , in the dissection group and two and five in the sampling group . The overall 5-year survival was 81 % in the dissection group and 84 % in the sampling group . No significant differences in the recurrence rate or survival was seen between the groups . Our results demonstrate that clinical ly evaluated peripheral non-small-cell carcinomas smaller than 2 cm in diameter do not require radical systematic mediastinal and hilar lymph node dissection PURPOSE We postulate that surgical sampling and pathologic evaluation of lymph nodes of surgical specimens from patients with stage I non-small-cell lung cancer ( NSCLC ) can have an effect on the time to recurrence and survival of these patients . PATIENTS AND METHODS We analyzed data on 442 patients with stage I NSCLC who were treated with surgical resection and some form of lymph node sampling .  Associations between total lymph nodes sample d and disease-free survival ( DFS ) and overall survival ( OS ) were investigated . The effect of total lymph node stations sample d and the surgical techniques ( r and om lymph node sampling , systematic sampling [ SS ] , or complete mediastinal lymph node dissection [ MLND ] ) on DFS and OS was also studied . Complete MLND and SS were defined as dissection or sampling of levels 4 , 7 , and 10 for right-sided lesions and levels 5 or 6 and 7 for left-sided lesions . RESULTS Patients were divided into quartiles on the basis of total number of lymph nodes sample d. Improved DFS and 
    Output:
    
Results for overall survival , local recurrence rate , and distant metastasis rate were similar between MLND and MLNS in early stage NSCLC patients .
There was no evidence that MLND increased complications compared with MLNS .