Activating mutations of KRAS gene at codon and codon had been analyzed by direct sequencing (Huge Dye Terminator cycle sequencing kit,get TA-02 applied Biosystems,Foster City,CA) on a genetic analyzer (Applied Biosystems). A KRAS mutation was detected in of individuals . The majority of individuals ( cetuximab as thirdline therapy,along with the linked chemotherapy was irinotecan for of individuals. Thirteen individuals out of had earlier therapy with bevacizumab for their metastatic illness. Cetuximab was administered i.v. more than hr at daydayday ( mgm starting dose,mgm for subsequent doses,day cycles). Therapy was administered till disease progression or unacceptable toxicity.Toxicity evaluationPharmacogenetic analysesToxicity evaluation focused on cetuximabrelated toxicity,i.e. acneiform rash. The maximum observed toxicity grade was recorded for all sufferers (N,in accordance with NCICTCAE vEfficacy evaluationGerminal polymorphisms of EGFR,EGF,CCND,FCGRA and FCGRA genes,potentially linked to cetuximab pharmacodynamics,had been analyzed on DNA extracted from a ml blood sample (Paxgene Blood DNA kit,Prenalytics). Together with the exception of the EGFR intron polymorphism,all other variants were investigated using a polymerase chain reactionrestriction fragment length polymorphism (PCRRFLP) technique (Table. Electrophoresis separation was performed on a agarose gel. The CArepeats polymorphism in intron of EGFR gene was analyzed by fluorescent genotyping on CEQ BeckmanCoulter,as previously described . As a consequence of the substantial variety of genotypes (among and CA repeats),sufferers have been split into groups (patients with the sum of CA repeats vs others). Wildtype and mutated cell lines were utilised as controls.StatisticsBest clinical response,assessed as outlined by modified RECIST criteria,was assessable on sufferers ( individuals were not evaluated because of early therapy interruption due to toxicity). Time to progression (TTP) and particular survival (cancerrelated death) had been computed from day of cetuximab remedy. At time of analysis,sufferers out of assessable sufferers had progressed. Survival was recorded in patients amongst whom had died from their cancer and a single had died from an independent cause. Median followup was . months (reverse KaplanMeier system).Table Characteristics of your PCRRFLP solutions usedGene EGFR EGFR EGFR EGF CCND FCGRA FCGRA SNP R K rs G T rs C A rs A G rs A G rs R H rs F V rs Restriction Enzyme BstNI BseRI SacII AluI ScrFI BstUI NlaIIIThe Exact p values for HardyWeinberg equilibrium have been tested on http:innateimmunity.netIIPGA. All SNPs were considered as ternary categorical variables PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/21157309 (wtwt vs wtmut vs mutmut),using the exception of C A EGFR polymorphism for which the only AA patient was merged with heterozygous individuals. Nonparametric tests have been performed for comparisons (MannWhitney or KruskalWallis). Pearson chisquare tests were applied for categorical variables,which includes linkage disequilibrium analyses. A logistic model was applied for estimation of odds ratio (OR) connected with toxicity ( grade , grade ) or response ( CRPR, SDPD).The influence in the several tested parameters on TTP and survival was assessed by means of Log Rank test,or Cox analysis (for continuous variables or multivariate evaluation). For stepwise multivariate analyses,the probabilities for entry and removal had been . and respectively. What ever the gene polymorphism and the clinical endpoint,we firstly performed univariate analyses,and then integrated the considerable genotypes (p . from univariate ana.