***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: Objective The purpose of this study was to investigate whether a long proximal oesophageal resection margin ( PRM ) is associated with improved survival after oesophagectomy for cancer and to identify the optimal margin to aim for in this patient group . Methods A prospect ively maintained data base identified 174 patients who underwent Ivor-Lewis oesophagectomy for cancer . Demographic , clinical , and pathological data were collected . X-tile software was used to identify the optimal resection point . Two models were analysed : single point resection with comparison of two groups ( short and long ) , and two resection points with three groups ( short , medium , and long ) to provide a range . Results The median PRM was 4.0 cm ( interquartile range : 2.5–6.0 cm ) . After adjustment for significant confounders , multivariable Cox PH analysis demonstrated that the optimal resection margin was 1.7 cm , and in the three-group analysis the optimum PRM was between 1.7 and 3 cm . In the two-group analysis , the long margin had no effect on DFS ( p = 0.37 ) , but carried a significantly improved overall survival ( hazard ratio [ HR ] = 0.46 , 95 % confidence interval [ CI ] 0.25–0.87 , p = 0.02 ) . In the three-group analysis , the medium and long groups had improved OS compared with the short group ( on average 54 % , HR ≥ 0.45 , p ≤ 0.04 ) . The 5-year disease-free and overall survival rates were highest in the medium PRM group ( 48 and 57 % respectively ) . Conclusions Optimal survival following oesophagectomy for cancer is achieved with a PRM > 1.7 cm , but a PRM > 3 cm does not yield a further survival advantage . Thus , the optimal PRM is likely to be between 1.7 and 3 cm Aims Neoadjuvant chemotherapy ( NAC ) remains an important therapeutic option for advanced oesophageal cancer ( OC ) . Pathological tumour regression grade ( TRG ) may offer additional information by directing adjuvant treatment and /or follow‐up but its clinical value remains unclear . We analysed the prognostic value of TRG and associated pathological factors in OC patients enrolled in the Medical Research Council ( MRC ) OE02 trial . Methods and results Histopathology was review ed in 497 resections from OE02 trial participants r and omised to surgery ( S group ; n = 244 ) or NAC followed by surgery [ chemotherapy plus surgery ( CS ) group ; n = 253 ] . The association between TRG groups [ responders ( TRG1–3 ) versus non‐responders ( TRG4–5 ) ] , pathological lymph node ( LN ) status and overall survival ( OS ) was analysed . One hundred and ninety‐five of 253 ( 77 % ) CS patients were classified as ‘ non‐responders ’ , with a significantly higher mortality risk compared to responders [ hazard ratio ( HR ) = 1.53 , 95 % confidence interval ( CI ) = 1.05–2.24 , P = 0.026 ] . OS was significantly better in patients without LN metastases irrespective of TRG [ non‐responders HR = 1.87 , 95 % CI = 1.33–2.63 , P < 0.001 versus responders HR = 2.21 , 95 % CI = 1.11–4.10 , P = 0.024 ] . In multivariate analyses , LN status was the only independent factor predictive of OS in CS patients ( HR = 1.93 , 95 % CI = 1.42–2.62 , P < 0.001 ) . Exploratory subgroup analyses excluding radiotherapy‐exposed patients ( n = 48 ) showed similar prognostic outcomes . Conclusion  Lymph node status post‐NAC is the most important prognostic factor in patients with resectable oesophageal cancer , irrespective of TRG . Potential clinical implication s , e.g. adjuvant treatment or intensified follow‐up , reinforce the importance of LN dissection for staging and prognostication OBJECTIVE To assess the clinical significance of circumferential resection margins according to current criteria of the College of American Pathologists ( CAP ) and the Royal College of Pathology ( RCP ) in esophageal and esophagogastric cancer . DESIGN Prospect i ve study . SETTING Single-surgeon data base . PATIENTS One hundred thirty-five patients ( mean age , 64 years ) with T3 tumors who underwent esophageal resection for cancer between 1991 and 2006 . Main Outcome Measure Resection margins criteria and survival . RESULTS Three hundred seventy-four consecutive patients were prospect ively identified from an institutional review board-approved data base between 1991 and 2006 . All patients with T3 tumors ( n = 135 ) had their original pathologic slides reassessed by a single gastrointestinal pathologist . Operative mortality was 0.7 % and mean follow-up was 3.1 years . Follow-up was complete in 81 % of patients . Positive margins were identified in 16 cases in the CAP group vs 83 cases in the RCP group . Five-year Kaplan-Meier survival curves in the CAP group demonstrated a significant ( P < .001 ) difference in survival , whereas the RCP group showed no difference ( P = .20 ) . In comparisons of negative vs positive margins , respectively , median survival in the CAP group ( 29.8 months [ 95 % confidence interval ( CI ) , 22.7 - 36.9 ] vs 8.33 months [ 95 % CI , 4.4 - 12.3 ] ) was significantly different from the RCP group ( 28.47 months [ 95 % CI , 19.7 - 37.2 ] vs 22.23 months [ 95 % CI , 13.6 - 30.8 ] ) . At 60-month follow-up , the positive predictive value with respect to survival was 100 % in the CAP group vs 81 % in the RCP group . Univariate and multivariate analyses identified R1 margins in the CAP group and lymph node ratio as being directly linked to survival . CONCLUSIONS Positive circumferential resection margins are prognostically important and the CAP criteria provide a more clinical ly meaningful assessment . Universal adoption of the CAP system can improve interpretation of international clinical trials and allow more accurate comparisons of outcomes SUMMARY . The failure of adjuvant therapy to significantly improve the prognosis of patients undergoing esophago-gastrectomy for cancer may be because of poor patient selection . We sought prognostic factors that would identify those patients who could benefit from adjuvant therapy . Data on 15 possible prognostic factors were prospect ively collected on 225 patients undergoing esophago-gastrectomy at a single institution , and univariate and multivariate analyzes performed . T , N , M and overall UICC stage , differentiation , involvement of the circumferential resection margin and number of metastatic of lymph nodes were identified as significant prognostic factors by univariate analysis . Multivariate analysis revealed that the completeness of resection ( R-category ) , ratio of metastatic to total nodes resected and the presence of vascular invasion were independently significant prognostic factors . Following R0 or R1 resection , patients with a metastatic to total lymph node ratio > 0.2 and ⁄or the presence of vascular invasion have a poor prognosis , and the effects of adjuvant therapy in these patients should be studied Background Controversy exists over the Sixth Edition of the International Union Against Cancer ( UICC ) TNM staging system for esophageal cancer . Inclusion of additional information such as the number of metastatic lymph nodes and extracapsular lymph node invasion may improve the current staging system and lead to optimization of patient treatment . Methods All patients in Adelaide who underwent resection for esophageal cancer between 1997 and 2007 were identified from a prospect i ve data base . Two independent observers then reexamined all pathology slides from the original resection . Univariate and multivariate analysis was performed to identify significant prognostic factors . The goodness of fit and accuracy of additional prognostic factors were assessed , and the staging system was modified according to this information . Results There were 240 patients ( mean age , 62 years ) who met the inclusion criteria . The 5-year overall survival rate was 36 % ( median , 24 months ) . Only histological grade and a refined pN stage were found to be independent prognostic factors that could then be used to improve current TNM staging . Subdivision of pN stage into three groups ( 0 , 1–2 , and > 2 positive nodes ) showed significant differences in 5-year survival between all three groups : 53 % vs 27 % vs 6 % , respectively ( P < .01 ) . The optimal staging model was the same for patients who received neoadjuvant therapy and surgery ( n = 116 ) , and those who underwent surgery alone ( n = 124 ) . Conclusion A staging model that incorporates a refined pN stage and histological grade appears to be more accurate than the current UICC-TNM staging system . This staging model is still applicable in patients who receive neoadjuvant therapy BACKGROUND For rectal carcinoma , the presence of tumour within 1 mm of the circumferential margin is an important independent prognostic factor for both local recurrence and survival . Similar prospect i ve data have not been reported for oesophageal carcinoma and we wished to ascertain the prognostic importance of this variable following potentially curative resection for oesophageal carcinoma . AIM To prospect ively assess the impact of circumferential margin involvement ( tumour within 1 mm ) following potentially curative resection for oesophageal carcinoma . PATIENTS AND METHODS In a prospect i ve study , resection specimens of 135 patients treated with potentially curative oesophageal resection alone  were studied for the presence of tumour within 1 mm of the circumferential margin ( margin positive ) , using inked margins and cross sectional slicing of the specimen . All tumours were also staged using the 1987 UICC TNM classification . Patients were followed for a mean of 19 months , and overall and cancer specific survival analysed . RESULTS The finding of tumour cells within 1 mm of the circumferential margin ( CRM+ ) was a significant and independent predictor of survival following potentially curative oesophageal resection . Overall , 64 ( 47 % ) patients were CRM+ . Median survival in this group was 21 months compared with 39 months in the CRM− group ( p=0.015 ) . The impact of CRM status on survival was only seen in patients with a low nodal metastatic burden ( < 25 % nodes positive ) . The odds ratio for the risk of dying from oesophageal cancer was 2.08 when the CRM was involved ( p=0.013 ) . CONCLUSIONS The presence of tumour within 1 mm of the circumferential margin following potentially curative resection for oesophageal carcinoma is an important independent prognostic variable and should be reported routinely Objective : To evaluate prognostic factors and tumor  staging  in patients after esophagectomy for cancer . Summary Background Data : Several reports have question ed the appropriateness of the sixth edition of the International Union Against Cancer ( UICC ) TNM guidelines for staging esophageal cancer . Additional pathologic characteristics , besides the 3 basic facets of anatomic spread ( tumor , node , metastases ) , might also have prognostic value . Methods : All patients who underwent resection of the esophagus for carcinoma between January 1995 and March 2003 were extracted from a prospect i ve data base . Univariate and multivariate analysis was performed to identify prognostic factors for survival . The goodness of fit and accuracy of 3 staging models ( UICC-TNM , Korst classification , Rice classification ) predicting survival were assessed . Results : A total of 292 patients ( mean age , 63 years ) underwent esophagectomy .  The 5-year overall survival rate was 29 % ( median , 21 months ) . pT- , pN- , pm-stage , and radicality of the resection were independent prognostic factors . Subdivision of T1 tumors into mucosal and submucosal showed significant differences in 5-year survival between both groups : 90 % versus 47 % , respectively ( P = 0.01 ) . Subdivision of pN-stage into 3 groups based on the number of positive nodes ( 0 , 1–2 , and > 3 nodes positive ) or the lymph node ratio ( 0 , 0.01–0.2 , and > 0.2 ) also refined staging ( P = 0.001 and P < 0.001 , respectively ) . The current subclassification of M1 ( M1a and M1b ) is not warranted ( P = 0.41 ) . The staging model of Rice was more accurate than the UICC-TNM classification in predicting survival . Conclusion : This study supports the view that the current ( 6th edition ) UICC-TNM staging model for esophageal cancer needs to be revised BACKGROUND A number of clinicopathological characteristics can influence survival following esophagectomy for cancer . The aim of this study was to determine the factors affecting survival in a consecutive series of patients undergoing esophagectomy for cancer at a single tertiary centre over a 7 year period . MATERIAL S & METHODS We analyzed a prospect i ve data base of 314 consecutive patients ( 247 males and  
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Conclusion A positive CRM is associated with a worse prognosis regardless of classification system , T category , tumour type or neoadjuvant therapy