despite the overall incidence of gastric cancer ( gc ) has declined in recent decades , it still represents the second cause of cancer - related death worldwide . the highest rates of survival have been recorded in japan , where its high incidence has led to implement screening measures among the population at high risk . these measures have achieved higher rates of earlier detection with an excellent prognosis [ 35 ] . spain records a survival rate above the european average , with 23% of patients alive at 5 years , except in one of its areas with higher incidence rates ( castilla and len ) where it has been registered the highest mortality . nowadays , the radical resection is still the mainstay of treatment and despite the progress made in surgical techniques and development of new therapeutic strategies with chemotherapy or perioperative chemoradiotherapy , there have not been a significant improvement in the overall survival ( os ) [ 3 , 7 ] .   in the recent years , there has been a change in the pattern of presentation of gc , with a relative increase in the incidence of proximal tumors . despite differences in their biological behavior with a more aggressive clinical course than distal tumours therefore , there is a wide heterogeneity among individuals with the same tumor stage . at this time , it would be necessary to have additional classification parameters or biomarkers to identify subgroups of patients with different biological profiles that correlate more closely with a prognosis and/or response to treatment .   in this context , recently , many biological factors involved in the genesis of sporadic gc have been known , although their clinical relevance has not been confirmed for most of them . protein is a transmembrane tyrosine kinase receptor and a member of the epidermal growth factor receptors ( egfrs ) family . all except her-3 share the same molecular structure with an extracellular domain of ligand binding , a short transmembrane domain , and an intracellular domain with tyrosine kinase activity . her-3 is a distinctive member of this family because its kinase domain lacks certain residues that are known to be essential for catalytic activity in other kinases . ligand binding to its receptor triggers a cascade of signals that influence many aspects of tumor biology as important as cell differentiation , proliferation , and cell survival [ 11 , 12 ] . her-2 protein is encoded by a gene located on chromosome 17q21 that acts as oncogene in carcinomas because its overexpression induces amplification of the protein in the cell membrane , and consequently the malignant cell gets favorable for their growth properties . the role of her-2 in the development of many types of cancer is well known , especially in invasive breast cancer in which overexpression of the protein in the cell membrane and/or gene amplification has been detected in 1034% , correlating with worse prognosis and being a predictor of poor response to chemotherapy and hormonal treatments . although this overexpression has also been detected in other tumors , including gc , its prognostic impact has not been definitively established [ 13 , 14 ] . the interest in this biological factor has been increased by the presence of trastuzumab , a humanized igg1 monoclonal antibody that specifically binds the extracellular domain of her-2 and increases survival rates in breast tumors early and at advanced stage . these results encourage to investigate the prognostic significance of her-2 protein in other types of tumors with high incidence and few therapeutic options , such as gc . overexpression of her-2 in this disease was first described in 1986 by immunohistochemistry ( ihc ) . several published series have shown positivity rates varying between 6.8% and 34% for ihc and 7.1% to 42.6% for the amplification of gene copy number by fluorescence in situ hybridization or fish [ 1517 ] . they have also shown higher positivity rates in intestinal type tumors and proximal location ( gastroesophageal junction ) . on the other hand , funato et al . , using gc cell lines that overexpress her-2 , found that this conferred sensitivity to cisplatin , suggesting that positivity could be a predictor of response to this drug . although several studies have attempted to demonstrate its prognostic role , this has not been definitively proven [ 13 , 14 ] . some studies have suggested that overexpression and/or amplification in gc after radical resection would be an independent prognostic factor related to the depth of gastric wall invasion , lymph node involvement , undifferentiated tumours , and reduced disease - free survival ( dfs ) or os [ 1517 , 19 ] . this study tries to demonstrate the relationship between her-2 positivity and survival in a specific population of patients living in an area of high risk of gc in the center of spain who underwent a complete resection . this was designed as a retrospective study of patients diagnosed with gc in the period from 2003 to 2005 which were analysed histopathologically at the department of pathology of the clinical university hospital of valladolid ( castilla and len , spain ) . men and women older than 18 years of age were eligible for inclusion if they had histologically confirmed adenocarcinoma of the stomach or gastrooesophageal junction . all of them had to be undergone a complete radical resection r0 and followed our institutional standard followup . the analyses were performed in tissue sections of 3 mm tissue blocks conventionally fixed in formalin and embedded in paraffin . these samples were subjected to analysis of overexpression by ihc , and in cases with + /++/+++ these samples underwent also an analysis of her-2 amplification using the techniques described below . tumours were tested for her-2 status with ihc through herceptest kit ( dako k5207 manual process number of the sample ) according to manufacturer protocols . for the assessment by ihc , we used the membrane stain graduations on a scale of 4 grades : 0 , 1 + , 2 + , 3 + according to the recommendations of the panel scoring gc   ( see table 1 ) . the rate of her-2 amplification was determined by the ratio between the number of copies of her-2/number of centromeres ( ratio of her-2/cep 17 ( centromeric probe 17 ) ) . polysomy of chromosome 17 was defined as 3 cep 17 signals per cell on average . if no consistent assessment , the case was analyzed by both of them , and the result was obtained by consensus . this technique was used in conjunction with ihc routinely in all patients with at least + ihc to assess concordance as it has been explained above . dfs was defined as time from radical surgery until recurrence , death of any cause other than cancer , or last followup . secondary endpoints included frequency of overexpression and/or amplification in gc , time to progression , and correlation between   the status of the overexpression and/or amplification with other pathological , anatomic , or relevant demographic features . we reviewed the medical records of each case and collected the clinical , demographic and pathological data . demographic data were area of origin of patients , age , and sex .   clinical and pathological data are , for example , tumor location , endoscopic appearance , histologic type of lauren , endoscopic diagnosis date , date of radical resection , tnm pathologic stage , ratio of metastatic nodes / analyzed nodes , adjuvant treatment , date of recurrence , location of recurrence , relapse type ( single / multiple ) , date of withdrawal or last follow - up visit schedule , patient status at the last visit , date of death , and cause . the data were included in a database designed for this purpose for subsequent statistical analysis using spss version 8.0 . we conducted a descriptive study of case characteristics in a pooled analysis stratified according to her-2 status . the survival data were analyzed according to kaplan - meier method , and statistical significance was tested using log - rank test . we have performed univariate and multivariate analysis to identify the role of overexpression and/or amplification of her-2 and other factors as prognostic indicators independently associated with dfs and os . high expression of her-2 protein by ihc 3 + was recorded in 8 cases , and overall expression ( ihc 3 + or ihc 2 +   and fish positive ) was detected in 7.5% of tumours . the incidence of c - erbb-2 positive was higher in women with tumors located primarily antropyloric ( although at this point has not been detected statistical significance ) and intestinal type . also a greater proportion of patients detected with advanced tumors ( pt3 - 4 and nodes involved ) in the subgroup of c - erbb-2 positive , as shown in table 4 .   after a median followup of 38 months ( range 1567 months ) , in patients with her-2 positive 66.6% recurrences were recorded ( 6 patients out of 9 ) .   in these cases , the median time to recurrence was 9 months ( range 216 months ) compared to 19 months ( range 1538 months ) in the sample of patients with her-2 negative , these differences being statistically significant ( p = 0.04 ) . most of recurrences in her-2 positive tumours were at distance or combined ( locoregional and distant ) , while in 1 of them only locoregional recurrence was detected in a control endoscopy although he was unfit to radical treatment . among patients who had recurrence of their tumour , it was observed a statistically significant difference in time to recurrence according to the status of c - erbb-2 . thus , the proportion of patients falling on the first year ( early relapse ) after diagnosis was higher in the her-2 positive subgroup ( 4 out of 6 patients ) than in the negative one ( 66.6% versus 35.4% , p = 0.048 ) . throughout the study period , we documented two ( 22.3% ) deaths due to tumor disease in the subgroup of patients with c - erbb-2 positive . in this subgroup , there were three people alive without evidence of disease . the median dfs for the population c - erbb-2 positive was 15 months ( range 267 months ) meanwhile for her-2 negative was 27 months ( range 567 months ) ( p = 0.04 ) . os for her-2 positive was 25 months ( range 1067 months ) but with c - erbb-2 negative was 47 months ( range 2967 months ) ( p = 0.039 ) . our univariate analysis showed that the status of her-2 , sex , advanced stage , and lymph node metastases were associated with poor survival . a multivariate cox analysis only identified the status of c - erbb-2 and the advanced stage as independent prognostic factors ( data not included ) . our results have found that overexpression of the protein her-2 by ihc confirmed by amplification of the her-2/neu oncogene in cases of ihc + + , and are independent prognostic factors in gc after radical resection , correlated statistically significant with early relapse ( during a year after radical resection ) .   in this regard , we found that , among recurrences that appear in this time period , 66.6% were in the her-2 positive subgroup compared to 35.4% detected in the c - erbb-2 negative ( p = 0.048 ) .   on the other hand , the univariate and multivariate analyses also revealed that it is an independent factor that correlates with worse survival . both facts make our results consistent with other published studies , prospective or retrospective , suggesting that the routine assessment of her-2/neu gene status should be a rule as it is a new prognostic factor in gc . this analysis detected also a statistically significant difference in the median time to relapse according to her-2 status subgroups . in this way we have obtained a shorter time in patients with her-2 positive ( median 9 months ) compared to her-2 negative sample ( 19 months ) . similarly there are differences in dfs or os favoring those cases in which overexpression and/or amplification of c - erbb-2 was not detected . , published in ann of surg oncol 2003 , revealed that survival data were also favorable to patients with her-2 negative in a statistically significant way   as our study found . we have also identified a statistically significant association between positivity for c - erbb-2 and female sex , undifferentiated histological - grade tumours , intestinal histological type , and presence of nodal metastases , showing an interesting correlation with the presence of more than 6 nodes metastatic ( p = 0.052 ) although with a marginal significance .   on the contrary we have not detected significant association with tumor location ( antropyloric versus other locations ) we differ from other published studies which have found a significant correlation between positivity for c - erbb-2 and the presence of tumours at the gastroesophageal junction . tanner et al . found that positive rates ranged from 24% to 12% for tumours located at the union or in other areas of the stomach , respectively , . the toga trial revealed in the same way and got a range between 32% and 18% , respectively .   on the other hand , recent studies have reported a high correlation between both overexpression by ihc and amplification by fish . the study by yano et al . found an overall concordance rate of 87% ( 58.8% for ihc + + and 88% in cases of ihc + + + ) . and all these studies have also showed high rates of agreement between surgical specimens and biopsy specimens .   against the others , the overall agreement we have obtained was 42.8% , which means that only 9 cases of 21 positive by ihc ( + to + + + ) showed oncogene amplification by fish . in the literature it is thought to be due to cases with ihc 0/1 + which had also gene amplification by fish . in toga trial this fact was detected in almost the same percentage of ihc + + and fish positive ( 23% and 26% , resp . ) . we have identified a concordance of 100% in cases with tumours her-2   with + + + by ihc so that all patients had oncogene amplification by fish . by contrast , in cases of ihc + + concordance was much lower , only found in 16.6% of patients . this finding could support the hypothesis that the amplification of the oncogene c - erbb-2 may not be the only mechanism involved in the overexpression of the protein in the cell membrane in gc as suggested kameda et al . . on the other hand , the work of hollywood and hurst   also suggested that overexpression of her-2 may occur through other molecular strategies such as transcriptional activation by other genes . another plausible explanation for this discrepancy could be related to the fact of low her-2 overexpression in cg . this may involve a higher rate of false positives to the nonspecific binding of primary antibody or to the overvaluation of the union . in summary , our study showed a low positivity rate of her-2 but similar to other series published in the literature , approaching to the initial series published in the 1990s or even the latest   grvalos and jimeno study . this is probably due to the exclusion of patients with metastases at diagnosis or even the extended period of time considered for the inclusion of patients in our project , with many differences in the protocols of fixation of the specimens that might contribute somewhat to the appearance of false negatives . the cg is the second leading cause of cancer death worldwide because most are diagnosed in advanced stages with no chance of cure . in this context , the systemic chemotherapy remains the only treatment option , although with poor results , so new strategies are needed . every time there is more evidence of the importance of her-2 in these patients , with the positivity correlated with poor survival outcomes due to the increased aggressiveness of the disease . there are experimental models showing that trastuzumab ( a monoclonal antibody that inhibits her-2 ) suppresses the growth of human gc . as a result of these promising data , there have been conducted clinical trials of this antibody in combination with platinum - based chemotherapy with good results . our work contributes to emphasize the importance of this biomarker in the context of a high - risk gc population in the center of spain . although this is a retrospective study with the limitations already described , the results provide us with a better understanding of the relevance of this protein as a prognostic marker and indirectly as a therapeutic target and encourage us to continue researching in molecular pathways to improve the overall results and to optimize the clinical application .
gastric cancer ( gc ) still represents the second cause of cancer - related death worldwide . 
 radical resection is the mainstay of early stages treatment with little impact on overall survival ( os )   in the advanced ones . 
 her-2 is the most relevant biological factor   involved . 
 purpose . 
 this study aims to show the relationship between her-2 positivity and survival in patients with completely resected gc . methods . 
 retrospective study of gc patients diagnosed in 20032005 at our institution . 
 surgical specimens underwent immunohistochemistry ( ihc ) , and in cases + /++/+++ samples underwent also fluorescence in situ hybridisation ( fish ) analyses of her-2 and graduated according to experts ' consensus . 
 results . 
 120 cases included . 
 overall expression detected in 7.5% . correlation between her-2 positive and female sex , advanced stages or histological grades , or intestinal type was detected . 
 early recurrences higher in her-2 positive   ( 66.6% versus 35.4% , p = 0.048 ) . 
 the median dfs for c - erbb-2 positive was 15 months ( range 267 months ) , and os was 25 months ( range 1067 months ) . in the case of patients with c - erbb-2 , 
 negative median dfs was 27 months ( range 567 months ) and os for this sample is 47 months ( range 2967 months ) . conclusions . 
 these results emphasize the relevance of her-2 positivity in gc as independent prognostic factor and support its current analyses in daily practice .