human
***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 survival benefit of adjuvant radiotherapy and 5-fluorouracil versus observation alone after surgery was investigated in patients with pancreatic head and periampullary cancers . SUMMARY BACKGROUND DATA A previous study of adjuvant radiotherapy and chemotherapy in these cancers by the Gastrointestinal Tract Cancer Cooperative Group of EORTC has been followed by other studies with conflicting results . METHODS Eligible patients with T1 - 2N0 - 1aM0 pancreatic head or T1 - 3N0 - 1aM0 periampullary cancer and histologically proven adenocarcinoma were r and omized after resection . RESULTS Between 1987 and 1995 , 218 patients were r and omized ( 108 patients in the observation group , 110 patients in the treatment group ) . Eleven patients were ineligible ( five in the observation group and six in the treatment group ) . Baseline characteristics were comparable between the two groups . One hundred fourteen patients ( 55 % ) had pancreatic cancer ( 54 in the observation group and 60 in the treatment group ) . In the treatment arm , 21 patients ( 20 % ) received no treatment because of postoperative complications or patient refusal . In the treatment group , only minor toxicity was observed . The median duration of survival was 19.0 months for the observation group and 24.5 months in the treatment group ( log-rank , p = 0.208 ) . The 2-year survival estimates were 41 % and 51 % , respectively . The results when stratifying for tumor location showed a 2-year survival rate of 26 % in the observation group and 34 % in the treatment group ( log-rank , p = 0.099 ) in pancreatic head cancer ; in periampullary cancer , the 2-year survival rate was 63 % in the observation group and 67 % in the treatment group ( log-rank , p = 0.737 ) . No reduction of locoregional recurrence rates was apparent in the groups . CONCLUSIONS Adjuvant radiotherapy in combination with 5-fluorouracil is safe and well tolerated . However , the benefit in this study was small ; routine use of adjuvant chemoradiotherapy is not warranted as st and ard treatment in cancer of the head of the pancreas or periampullary region The efficacy of combined radiation and fluorouracil as adjuvant therapy for pancreatic cancer is suggested by a prospect i ve r and omized study conducted by the Gastrointestinal Tumor Study Group ( GITSG ) . Twenty-two patients r and omized to no adjuvant treatment and 21 to combined therapy were analyzed . Neither life-threatening toxic reaction nor death due to toxic effect was encountered . The study was terminated prematurely because of an unacceptably low rate of accrual combined with the observation of increasingly large survival differences between the study arms . Median survival for the treatment group ( 20 months ) was significantly longer than that observed for the control group ( 11 months ) . Four patients , three in the treated and one in the control group , have survived five years or longer following surgery . The extent of the tumor and initial performance status were significantly and independently related to survival OBJECTIVE This study was design ed to evaluate prospect ively survival after pancreaticoduodenectomy for pancreatic adenocarcinoma , comparing two different postoperative adjuvant chemoradiation protocol to those of no adjuvant therapy . SUMMARY BACKGROUND DATA Based on limited data from the Gastrointestinal Tumor Study Group , adjuvant chemoradiation therapy has been recommended after pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancrease . However , many patients continue to receive no such therapy . METHODS From October 1991 through September 1995 , all patients with resected , pathologically confirmed adenocarcinoma of the head , neck , or uncinate process of the pancreas were review ed by a multidisciplinary group ( surgery , radiation oncology , medical oncology , and pathology ) and were offered three options for postoperative treatment after pancreaticoduodenectomy : 1 ) st and ard therapy : external beam radiation therapy to the pancreatic bed ( 4000 - 4500 cGy ) given with two 3-day fluorouracil ( 5-FU ) courses and followed by weekly bolus 5-FU ( 500 mg/m2 per day ) for 4 months ; 2 ) intensive therapy : external beam radiation therapy to the pancreatic bed ( 5040 - 5760 cGy ) with prophylactic hepatic irradiation ( 2340 - 2700 cGy ) given with and followed by infusional 5-FU ( 200 mg/m2 per day ) plus leucovorin ( 5 mg/m2 per day ) for 5 of 7 days for 4 months ; or 3 ) no therapy : no postoperative radiation therapy or chemotherapy . RESULTS Pancreaticoduodenectomy was performed in 174 patients , with 1 in-hospital death ( 0.6 % ) . Ninety-nine patients elected st and ard therapy , 21 elected intensive therapy , and 53 patients declined therapy . The three groups were comparable with respect to race , gender , intraoperative blood loss , tumor differentiation , lymph node status , tumor diameter , and resection margin status . Univariate analyses indicated that tumor diameter < 3 cm , intraoperative blood loss < 700 mL , absence of intraoperative blood transfusions , and use of adjuvant chemoradiation therapy  were associated with significantly longer survival ( p < 0.05 ) . By Cox proportional hazards survival analysis , the most powerful predictors of outcome were tumor diameter , intraoperative blood loss , status of resection margins , and use of postoperative adjuvant therapy . The use of postoperative adjuvant chemoradiation therapy was a predictor of improved survival ( median survival , 19.5 months compared to 13.5 months without therapy ; p = 0.003 ) . The intensive therapy group had no survival advantage when compared to that of the st and ard therapy group ( median survival , 17.5 months vs. 21 months , p = not significant ) . CONCLUSIONS Adjuvant chemoradiation therapy significantly improves survival after pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas . Based on these survival data , st and ard adjuvant chemoradiation therapy appears to be indicated for patients treated by pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas .  Intensive therapy conferred no survival advantage over st and ard therapy in this analysis This large-volume , single-institution review examines factors influencing long-term survival after resection in patients with adenocarcinoma of the head , neck , uncinate process , body , or tail of the pancreas . Between January 1984 and July 1999 inclusive , 616 patients with adenocarcinoma of the pancreas underwent surgical resection .  A retrospective analysis of a prospect ively collected data base was performed . Both univariate and multivariate models were used to determine the factors influencing survival . Of the 616 patients , 526 ( 85 % ) underwent pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas , 52 ( 9 % ) underwent distal pancreatectomy  for adenocarcinoma of the body or tail , and 38 ( 6 % ) underwent total pancreatectomy for adenocarcinoma extensively involving the gl and . The mean age of the patients was 64.3 years , with 54 % being male and 91 % being white . The overall perioperative mortality rate was 2.3 % , whereas the incidence of postoperative complications was 30 % . The median postoperative length of stay was 11 days . The mean tumor diameter was 3.2 cm , with 72 % of patients having positive lymph nodes , 30 % having positive resection margins , and 36 % having poorly differentiated tumors . Patients undergoing distal pancreatectomy for left-sided lesions had larger tumors ( 4.7 vs. 3.1 cm , P < 0.0001 ) , but fewer node-positive resections ( 59 % vs. 73 % , P = 0.03 ) and fewer poorly differentiated tumors ( 29 % vs. 36 % , P<0.001 ) , as compared to those undergoing pancreaticoduodenectomy for right-sided lesions . The overall survival of the entire cohort was 63 % at 1 year and 17 % at 5 years , with a median survival of 17 months . For right-sided lesions the 1- and 5-year survival rates were 64 % and 17 % , respectively , compared to 50 % and 15 % for left-sided lesions . Factors shown to have favorable independent prognostic significance by multivariate analysis were negative resection margins ( hazard ratio [ HR ] = 0.64 , confidence interval [ CI ] = 0.50 to 0.82 , P = 0.0004 ) , tumor diameter less than 3 cm ( HR = 0.72 , CI = 0.57 to 0.90 , P = 0.004 ) , estimated blood loss less than 750 ml ( HR = 0.75 , CI = 0.58 to 0.96 , P = 0.02 ) , well/moderate tumor differentiation ( HR = 0.71 , CI = 0.56 to 0.90 , P = 0.005 ) , and postoperative chemoradiation ( HR = 0.50 , CI = 0.39 to 0.64 , P } < 0.0001 ) . Tumor location in head , neck , or uncinate process approached significance in the final multivariate model ( HR = 0.60 , CI = 0.35 to 1.0 , P = 0.06 ) . Pancreatic resection remains the only hope for long-term survival in patients with adenocarcinoma of the pancreas . Completeness of resection and tumor characteristics including tumor size and degree of differentiation are important independent prognostic indicators . Adjuvant chemoradiation is a strong predictor of outcome and likely decreases the independent significance of tumor location and nodal status PURPOSE The addition of radiation to adjuvant 5-fluorouracil for the treatment of pancreatic cancer has not yet shown any definite benefit . Gemcitabine ( GEM ) has potential activity in advanced pancreatic cancer and is a powerful radiosensitizer . We evaluated the feasibility of postoperative administration of GEM alone , followed by concurrent GEM and irradiation ( RT ) after curative resection for pancreatic adenocarcinoma . METHODS AND MATERIAL S GEM 1000 mg/m(2 ) on Days 1 and 8 every 21 days for three courses was given within 8 weeks after surgery and was followed by GEM 300 mg/m(2 ) weekly + 40 Gy in a split course . Twenty-two patients ( median age 59 years , range 39 - 74 , Performance Status 0 - 1 ) with Stage II and III curatively resected pancreatic head adenocarcinoma were included . RESULTS For GEM alone , all patients received the three planned courses , with dose reductions in 7 ( 32 % ) of 22 patients . All patients , except two , completed full chemoradiation ; one received only 20 Gy because of both World Health Organization Grade 4 vomiting and thrombopenia and the other stopped RT after 32 Gy because of early disease progression . No reduction in GEM during RT was necessary ; no toxic death was noted ; and World Health Organization Grade 3 - 4 hematologic and nonhematologic toxicities occurred in 8 ( 36 % ) and 7 ( nausea , vomiting ) ( 32 % ) of 22 patients respectively . No late toxicity developed . After a median follow-up of 15 months , 11 patients were alive , and 2 patients had died of causes unrelated to their disease or toxicity , The median disease-free survival and overall survival was 6 and 15 months , respectively . CONCLUSION This adjuvant regimen was well tolerated and can be easily administered after curative surgery for pancreatic cancer . Its intensification with continuous RT is currently being investigated Purpose To evaluate in a prospect i ve r and omized study the long-term results of adjuvant locoregional chemoimmunotherapy in a number of patients with stage III pancreatic duct cancer who underwent pancreatic resection between November 1993 and October 2000 . Methods One hundred twenty-eight patients were divided into three groups . Group A ( n = 40 ) patients had surgical resection alone . Group B ( n = 45 ) patients had , using a side arterial branch of the jejunal artery , an arterial catheter advanced under fluoroscopic control into the superior mesenteric artery . Group B patients also received adjuvant chemotherapy . Group C ( n = 43 ) patients had the same kind of arterial catheter and received as an adjuvant treatment locoregional chemoimmunotherapy . During the initial surgical exploration , all patients underwent pancreatic resection . Pancreatic resection involved a st and ard technique of extended duodenopancreatectomy with regional lymphadenectomy and was carried out in all patients by the first author . At the end of intervention , all patients were r and 
    Output:
    
agent
***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 survival benefit of adjuvant radiotherapy and 5-fluorouracil versus observation alone after surgery was investigated in patients with pancreatic head and periampullary cancers . SUMMARY BACKGROUND DATA A previous study of adjuvant radiotherapy and chemotherapy in these cancers by the Gastrointestinal Tract Cancer Cooperative Group of EORTC has been followed by other studies with conflicting results . METHODS Eligible patients with T1 - 2N0 - 1aM0 pancreatic head or T1 - 3N0 - 1aM0 periampullary cancer and histologically proven adenocarcinoma were r and omized after resection . RESULTS Between 1987 and 1995 , 218 patients were r and omized ( 108 patients in the observation group , 110 patients in the treatment group ) . Eleven patients were ineligible ( five in the observation group and six in the treatment group ) . Baseline characteristics were comparable between the two groups . One hundred fourteen patients ( 55 % ) had pancreatic cancer ( 54 in the observation group and 60 in the treatment group ) . In the treatment arm , 21 patients ( 20 % ) received no treatment because of postoperative complications or patient refusal . In the treatment group , only minor toxicity was observed . The median duration of survival was 19.0 months for the observation group and 24.5 months in the treatment group ( log-rank , p = 0.208 ) . The 2-year survival estimates were 41 % and 51 % , respectively . The results when stratifying for tumor location showed a 2-year survival rate of 26 % in the observation group and 34 % in the treatment group ( log-rank , p = 0.099 ) in pancreatic head cancer ; in periampullary cancer , the 2-year survival rate was 63 % in the observation group and 67 % in the treatment group ( log-rank , p = 0.737 ) . No reduction of locoregional recurrence rates was apparent in the groups . CONCLUSIONS Adjuvant radiotherapy in combination with 5-fluorouracil is safe and well tolerated . However , the benefit in this study was small ; routine use of adjuvant chemoradiotherapy is not warranted as st and ard treatment in cancer of the head of the pancreas or periampullary region The efficacy of combined radiation and fluorouracil as adjuvant therapy for pancreatic cancer is suggested by a prospect i ve r and omized study conducted by the Gastrointestinal Tumor Study Group ( GITSG ) . Twenty-two patients r and omized to no adjuvant treatment and 21 to combined therapy were analyzed . Neither life-threatening toxic reaction nor death due to toxic effect was encountered . The study was terminated prematurely because of an unacceptably low rate of accrual combined with the observation of increasingly large survival differences between the study arms . Median survival for the treatment group ( 20 months ) was significantly longer than that observed for the control group ( 11 months ) . Four patients , three in the treated and one in the control group , have survived five years or longer following surgery . The extent of the tumor and initial performance status were significantly and independently related to survival OBJECTIVE This study was design ed to evaluate prospect ively survival after pancreaticoduodenectomy for pancreatic adenocarcinoma , comparing two different postoperative adjuvant chemoradiation protocol to those of no adjuvant therapy . SUMMARY BACKGROUND DATA Based on limited data from the Gastrointestinal Tumor Study Group , adjuvant chemoradiation therapy has been recommended after pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancrease . However , many patients continue to receive no such therapy . METHODS From October 1991 through September 1995 , all patients with resected , pathologically confirmed adenocarcinoma of the head , neck , or uncinate process of the pancreas were review ed by a multidisciplinary group ( surgery , radiation oncology , medical oncology , and pathology ) and were offered three options for postoperative treatment after pancreaticoduodenectomy : 1 ) st and ard therapy : external beam radiation therapy to the pancreatic bed ( 4000 - 4500 cGy ) given with two 3-day fluorouracil ( 5-FU ) courses and followed by weekly bolus 5-FU ( 500 mg/m2 per day ) for 4 months ; 2 ) intensive therapy : external beam radiation therapy to the pancreatic bed ( 5040 - 5760 cGy ) with prophylactic hepatic irradiation ( 2340 - 2700 cGy ) given with and followed by infusional 5-FU ( 200 mg/m2 per day ) plus leucovorin ( 5 mg/m2 per day ) for 5 of 7 days for 4 months ; or 3 ) no therapy : no postoperative radiation therapy or chemotherapy . RESULTS Pancreaticoduodenectomy was performed in 174 patients , with 1 in-hospital death ( 0.6 % ) . Ninety-nine patients elected st and ard therapy , 21 elected intensive therapy , and 53 patients declined therapy . The three groups were comparable with respect to race , gender , intraoperative blood loss , tumor differentiation , lymph node status , tumor diameter , and resection margin status . Univariate analyses indicated that tumor diameter < 3 cm , intraoperative blood loss < 700 mL , absence of intraoperative blood transfusions , and use of adjuvant chemoradiation therapy  were associated with significantly longer survival ( p < 0.05 ) . By Cox proportional hazards survival analysis , the most powerful predictors of outcome were tumor diameter , intraoperative blood loss , status of resection margins , and use of postoperative adjuvant therapy . The use of postoperative adjuvant chemoradiation therapy was a predictor of improved survival ( median survival , 19.5 months compared to 13.5 months without therapy ; p = 0.003 ) . The intensive therapy group had no survival advantage when compared to that of the st and ard therapy group ( median survival , 17.5 months vs. 21 months , p = not significant ) . CONCLUSIONS Adjuvant chemoradiation therapy significantly improves survival after pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas . Based on these survival data , st and ard adjuvant chemoradiation therapy appears to be indicated for patients treated by pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas .  Intensive therapy conferred no survival advantage over st and ard therapy in this analysis This large-volume , single-institution review examines factors influencing long-term survival after resection in patients with adenocarcinoma of the head , neck , uncinate process , body , or tail of the pancreas . Between January 1984 and July 1999 inclusive , 616 patients with adenocarcinoma of the pancreas underwent surgical resection .  A retrospective analysis of a prospect ively collected data base was performed . Both univariate and multivariate models were used to determine the factors influencing survival . Of the 616 patients , 526 ( 85 % ) underwent pancreaticoduodenectomy for adenocarcinoma of the head , neck , or uncinate process of the pancreas , 52 ( 9 % ) underwent distal pancreatectomy  for adenocarcinoma of the body or tail , and 38 ( 6 % ) underwent total pancreatectomy for adenocarcinoma extensively involving the gl and . The mean age of the patients was 64.3 years , with 54 % being male and 91 % being white . The overall perioperative mortality rate was 2.3 % , whereas the incidence of postoperative complications was 30 % . The median postoperative length of stay was 11 days . The mean tumor diameter was 3.2 cm , with 72 % of patients having positive lymph nodes , 30 % having positive resection margins , and 36 % having poorly differentiated tumors . Patients undergoing distal pancreatectomy for left-sided lesions had larger tumors ( 4.7 vs. 3.1 cm , P < 0.0001 ) , but fewer node-positive resections ( 59 % vs. 73 % , P = 0.03 ) and fewer poorly differentiated tumors ( 29 % vs. 36 % , P<0.001 ) , as compared to those undergoing pancreaticoduodenectomy for right-sided lesions . The overall survival of the entire cohort was 63 % at 1 year and 17 % at 5 years , with a median survival of 17 months . For right-sided lesions the 1- and 5-year survival rates were 64 % and 17 % , respectively , compared to 50 % and 15 % for left-sided lesions . Factors shown to have favorable independent prognostic significance by multivariate analysis were negative resection margins ( hazard ratio [ HR ] = 0.64 , confidence interval [ CI ] = 0.50 to 0.82 , P = 0.0004 ) , tumor diameter less than 3 cm ( HR = 0.72 , CI = 0.57 to 0.90 , P = 0.004 ) , estimated blood loss less than 750 ml ( HR = 0.75 , CI = 0.58 to 0.96 , P = 0.02 ) , well/moderate tumor differentiation ( HR = 0.71 , CI = 0.56 to 0.90 , P = 0.005 ) , and postoperative chemoradiation ( HR = 0.50 , CI = 0.39 to 0.64 , P } < 0.0001 ) . Tumor location in head , neck , or uncinate process approached significance in the final multivariate model ( HR = 0.60 , CI = 0.35 to 1.0 , P = 0.06 ) . Pancreatic resection remains the only hope for long-term survival in patients with adenocarcinoma of the pancreas . Completeness of resection and tumor characteristics including tumor size and degree of differentiation are important independent prognostic indicators . Adjuvant chemoradiation is a strong predictor of outcome and likely decreases the independent significance of tumor location and nodal status PURPOSE The addition of radiation to adjuvant 5-fluorouracil for the treatment of pancreatic cancer has not yet shown any definite benefit . Gemcitabine ( GEM ) has potential activity in advanced pancreatic cancer and is a powerful radiosensitizer . We evaluated the feasibility of postoperative administration of GEM alone , followed by concurrent GEM and irradiation ( RT ) after curative resection for pancreatic adenocarcinoma . METHODS AND MATERIAL S GEM 1000 mg/m(2 ) on Days 1 and 8 every 21 days for three courses was given within 8 weeks after surgery and was followed by GEM 300 mg/m(2 ) weekly + 40 Gy in a split course . Twenty-two patients ( median age 59 years , range 39 - 74 , Performance Status 0 - 1 ) with Stage II and III curatively resected pancreatic head adenocarcinoma were included . RESULTS For GEM alone , all patients received the three planned courses , with dose reductions in 7 ( 32 % ) of 22 patients . All patients , except two , completed full chemoradiation ; one received only 20 Gy because of both World Health Organization Grade 4 vomiting and thrombopenia and the other stopped RT after 32 Gy because of early disease progression . No reduction in GEM during RT was necessary ; no toxic death was noted ; and World Health Organization Grade 3 - 4 hematologic and nonhematologic toxicities occurred in 8 ( 36 % ) and 7 ( nausea , vomiting ) ( 32 % ) of 22 patients respectively . No late toxicity developed . After a median follow-up of 15 months , 11 patients were alive , and 2 patients had died of causes unrelated to their disease or toxicity , The median disease-free survival and overall survival was 6 and 15 months , respectively . CONCLUSION This adjuvant regimen was well tolerated and can be easily administered after curative surgery for pancreatic cancer . Its intensification with continuous RT is currently being investigated Purpose To evaluate in a prospect i ve r and omized study the long-term results of adjuvant locoregional chemoimmunotherapy in a number of patients with stage III pancreatic duct cancer who underwent pancreatic resection between November 1993 and October 2000 . Methods One hundred twenty-eight patients were divided into three groups . Group A ( n = 40 ) patients had surgical resection alone . Group B ( n = 45 ) patients had , using a side arterial branch of the jejunal artery , an arterial catheter advanced under fluoroscopic control into the superior mesenteric artery . Group B patients also received adjuvant chemotherapy . Group C ( n = 43 ) patients had the same kind of arterial catheter and received as an adjuvant treatment locoregional chemoimmunotherapy . During the initial surgical exploration , all patients underwent pancreatic resection . Pancreatic resection involved a st and ard technique of extended duodenopancreatectomy with regional lymphadenectomy and was carried out in all patients by the first author . At the end of intervention , all patients were r and 
    Output:
    