***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 Patients with metastatic colorectal cancer that harbors KRAS mutations in exon 2 do not benefit from anti-epidermal growth factor receptor ( EGFR ) therapy . Other activating RAS mutations may also be negative predictive biomarkers for anti-EGFR therapy . METHODS In this prospect ive-retrospective analysis , we assessed the efficacy and safety of panitumumab plus oxaliplatin , fluorouracil , and leucovorin ( FOLFOX4 ) as compared with FOLFOX4 alone , according to RAS ( KRAS or NRAS ) or BRAF mutation status . A total of 639 patients who had metastatic colorectal cancer without KRAS mutations in exon 2 had results for at least one of the following : KRAS exon 3 or 4 ; NRAS exon 2 , 3 , or 4 ; or BRAF exon 15 . The overall rate of ascertainment of RAS status was 90 % . RESULTS Among 512 patients without RAS mutations , progression-free survival was 10.1 months with panitumumab-FOLFOX4 versus 7.9 months with FOLFOX4 alone ( hazard ratio for progression or death with combination therapy , 0.72 ; 95 % confidence interval [ CI ] , 0.58 to 0.90 ; P=0.004 ) . Overall survival was 26.0 months in the panitumumab-FOLFOX4 group versus 20.2 months in the FOLFOX4-alone group ( hazard ratio for death , 0.78 ; 95 % CI , 0.62 to 0.99 ; P=0.04 ) . A total of 108 patients ( 17 % ) with nonmutated KRAS exon 2 had other RAS mutations . These mutations were associated with inferior progression-free survival and overall survival with panitumumab-FOLFOX4 treatment , which was consistent with the findings in patients with KRAS mutations in exon 2 .  BRAF mutations were a negative prognostic factor . No new safety signals were identified . CONCLUSIONS Additional RAS mutations predicted a lack of response in patients who received panitumumab-FOLFOX4 . In patients who had metastatic colorectal cancer without RAS mutations , improvements in overall survival were observed with panitumumab-FOLFOX4 therapy . ( Funded by Amgen and others ; PRIME Clinical Trials.gov number , NCT00364013 . ) BACKGROUND Cetuximab , an IgG1 chimeric monoclonal antibody against epidermal growth factor receptor ( EGFR ) , has activity against colorectal cancers that express EGFR . METHODS From December 2003 to August 2005 , 572 patients who had colorectal cancer expressing immunohistochemically detectable EGFR and who had been previously treated with a fluoropyrimidine , irinotecan , and oxaliplatin or had contraindications to treatment with these drugs underwent r and omization to an initial dose of 400 mg of cetuximab per square meter of body-surface area followed by a weekly infusion of 250 mg per square meter plus best supportive care  ( 287 patients ) or best supportive care alone  ( 285 patients ) . The primary end point was overall survival . RESULTS In comparison with best supportive care alone , cetuximab treatment was associated with a significant improvement in overall survival ( hazard ratio for death , 0.77 ; 95 % confidence interval [ CI ] , 0.64 to 0.92 ; P=0.005 ) and in progression-free survival ( hazard ratio for disease progression or death , 0.68 ; 95 % CI , 0.57 to 0.80 ; P<0.001 ) . These benefits were robust after adjustment in a multivariable Cox proportional-hazards model . The median overall survival was 6.1 months in the cetuximab group and 4.6 months in the group assigned to supportive care alone . Partial responses occurred in 23 patients ( 8.0 % ) in the cetuximab group but in none in the group assigned to supportive care alone ( P<0.001 ) ; the disease was stable in an additional 31.4 % of patients assigned to cetuximab and in 10.9 % of patients assigned to supportive care alone ( P<0.001 ) . Quality of life was better preserved in the cetuximab group , with less deterioration in physical function and global health status scores ( both P<0.05 ) . Cetuximab treatment was associated with a characteristic rash ; a rash of grade 2 or higher was strongly associated with improved survival ( hazard ratio for death , 0.33 ; 95 % CI , 0.22 to 0.50 ; P<0.001 ) . The incidence of any adverse event of grade 3 or higher was 78.5 % in the cetuximab group and 59.1 % in the group assigned to supportive care alone ( P<0.001 ) . CONCLUSIONS Cetuximab improves overall survival and progression-free survival and preserves quality -of-life measures in patients with colorectal cancer in whom other treatments have failed . ( Clinical Trials.gov number , NCT00079066 [ Clinical Trials.gov ] . ) Summary Background Therapeutic antibodies targeting EGFR have activity in advanced colorectal cancer , but results from clinical trials are inconsistent and the population in which most benefit is derived is uncertain . Our aim was to assess the addition of panitumumab to irinotecan in pretreated advanced colorectal cancer . Methods In this open-label , r and omised trial , we enrolled patients who had advanced colorectal cancer progressing after fluoropyrimidine treatment with or without oxaliplatin from 60 centres in the UK . From December , 2006 until June , 2008 , molecularly unselected patients were recruited to a three-arm design including irinotecan ( control ) , irinotecan plus ciclosporin , and irinotecan plus panitumumab ( IrPan ) groups . From June 10 , 2008 , in response to new data , the trial was amended to a prospect ively stratified design , restricting panitumumab r and omisation to patients with KRAS wild-type tumours ; the results of the comparison between the irinotcan and IrPan groups are reported here . We used a computer-generated r and omisation sequence ( stratified by previous EGFR targeted therapy and then minimised by centre , WHO performance status , previous oxaliplatin , previous bevacizumab , previous dose modifications , and best previous response ) to r and omly allocate patients to either irinotecan or IrPan . Patients in both groups received 350 mg/m2 intravenous irinotecan every 3 weeks ( 300 mg/m2 if aged ≥70 years or a performance status of 2 ) ; patients in the IrPan group also received intravenous panitumumab 9 mg/kg every 3 weeks . The primary endpoint was overall survival in KRAS wild-type patients who had not received previous EGFR targeted therapy , analysed by intention to treat . Tumour DNA was pyrosequenced for KRASc.146 , BRAF , NRAS , and PIK3CA mutations , and predefined molecular subgroups were analysed for interaction with the effect of panitumumab . This study is registered , number IS RCT N93248876 . Results Between Dec 4 , 2006 , and Aug 31 , 2010 , 1198 patients were enrolled , of whom 460 were included in the primary population of patients with KRASc.12–13,61 wild-type tumours and no previous EGFR targeted therapy . 230 patients were r and omly allocated to irinotecan and 230 to IrPan . There was no difference in overall survival between groups ( HR 1·01 , 95 % CI 0·83–1·23 ; p=0·91 ) , but individuals in the IrPan group had longer progression-free survival ( 0·78 , 0·64–0·95 ; p=0·015 ) and a greater number of responses ( 79 [ 34 % ] patients vs 27 [ 12 % ] ; p<0·0001 ) than did individuals in the irinotecan group . Grade 3 or worse diarrhoea ( 64 [ 29 % ] of 219 patients vs 39 [ 18 % ] of 218 patients ) , skin toxicity ( 41 [ 19 % ] vs none ) , lethargy ( 45 [21]% vs 24 [ 11 % ] ) , infection ( 42 [ 19 % ] vs 22 [ 10 % ] ) and haematological toxicity ( 48 [ 22 % ] vs 27 [ 12 % ] ) were reported more commonly in the IrPan group than in the irinotecan group . We recorded five treatment-related deaths , two in the IrPan group and three in the irinotecan group . Interpretation Adding panitumumab to irinotecan did not improve the overall survival of patients with wild-type KRAS tumours . Further refinement of molecular selection is needed for substantial benefits to be derived from EGFR targeting agents . Funding Cancer Research UK , Amgen 
    Output:
    
The choice of an anti-EGFR MoAb as first-line biologic is a valid option in RAS wild-type patients c and i date to a doublet with infusional 5-FU .