***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: PURPOSE The first planned interim analysis ( median follow-up , 3 years ) of the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer confirmed that the oral fluoropyrimidine derivative S-1 significantly improved overall survival , the primary end point . The results were therefore opened at the recommendation of an independent data and safety monitoring committee . We report 5-year follow-up data on patients enrolled onto the ACTS-GC study . PATIENTS AND METHODS Patients with histologically confirmed stage II or III gastric cancer who underwent gastrectomy with D2 lymphadenectomy were r and omly assigned to receive S-1 after surgery or surgery only . S-1 ( 80 to 120 mg per day ) was given for 4 weeks , followed by 2 weeks of rest . This 6-week cycle was repeated for 1 year . The primary end point was overall survival , and the secondary end points were relapse-free survival and safety . RESULTS The overall survival rate at 5 years was 71.7 % in the S-1 group and 61.1 % in the surgery-only group ( hazard ratio [ HR ] , 0.669 ; 95 % CI , 0.540 to 0.828 ) . The relapse-free survival rate at 5 years was 65.4 % in the S-1 group and 53.1 % in the surgery-only group ( HR , 0.653 ; 95 % CI , 0.537 to 0.793 ) . Subgroup analyses according to principal demographic factors such as sex , age , disease stage , and histologic type showed no interaction between treatment and any characteristic . CONCLUSION On the basis of 5-year follow-up data , postoperative adjuvant therapy with S-1 was confirmed to improve overall survival and relapse-free survival in patients with stage II or III gastric cancer who had undergone D2 gastrectomy Background Radical surgery is the cornerstone in the treatment of resectable gastric cancer . The Intergroup 0116 and MAGIC trials have shown benefit of postoperative chemoradiation and perioperative chemotherapy , respectively . Since these trials can not be compared directly , both regimens are evaluated prospect ively in the CRITICS trial . This study aims to obtain an improved overall survival for patients treated with preoperative chemotherapy and surgery  by incorporating radiotherapy concurrently with chemotherapy postoperatively . Methods / design In this phase III multicentre study , patients with resectable gastric cancer are treated with three cycles of preoperative ECC ( epirubicin , cisplatin and capecitabine ) , followed by surgery with adequate lymph node dissection , and then either another three cycles of ECC or concurrent chemoradiation ( 45 Gy , cisplatin and capecitabine ) . Surgical , pathological , and radiotherapeutic quality control is performed . The primary endpoint is overall survival , secondary endpoints are disease-free survival ( DFS ) , toxicity , health-related quality of life ( HRQL ) , prediction of response , and recurrence risk assessed by genomic and expression profiling . Accrual for the CRITICS trial is from the Netherl and s , Sweden , and Denmark , and more countries are invited to participate . Conclusion Results of this study will demonstrate whether the combination of preoperative chemotherapy and postoperative chemoradiotherapy will improve the clinical outcome of the current European st and ard of perioperative chemotherapy , and will therefore play a key role in the future management of patients with resectable gastric cancer . Trial registration clinical trials.gov PURPOSE The Intergroup 0116 trial has demonstrated that postoperative chemoradiotherapy ( CRT ) improves survival in gastric cancer . We retrospectively compared survival and recurrence patterns in two phase I/II studies evaluating more intensified postoperative CRT with those from the Dutch Gastric Cancer Group Trial ( DGCT ) that r and omly assigned patients between D1 and D2 lymphadenectomy . PATIENTS AND METHODS Survival and recurrence patterns of 91 patients with adenocarcinoma of the stomach who had received surgery followed by radiotherapy combined with fluorouracil and leucovorin ( n = 5 ) , capecitabine ( n = 39 ) , or capecitabine and cisplatin ( n = 47 ) were analyzed and compared with survival and  recurrence patterns  of 694 patients from the DGCT ( D1 , n = 369 ; D2 , n = 325 ) . For both groups , the Maruyama Index of Unresected Disease ( MI ) was calculated and correlated with survival and recurrence patterns . RESULTS With a median follow-up of 19 months in the CRT group , local recurrence rate after 2 years was significantly higher in the surgery only ( DGCT ) group ( 17 % v 5 % ; P = .0015 ) . Separate analysis of CRT patients who underwent a D1 dissection ( n = 39 ) versus DGCT-D1 ( n = 369 ) showed fewer local recurrences after chemoradiotherapy ( 2 % v 8 % ; P = .001 ) , whereas comparison of CRT-D2 ( n = 25 ) versus DGCT-D2 ( n = 325 ) demonstrated no significant difference . CRT significantly improved survival after a microscopically irradical ( R1 ) resection . The MI was found to be a strong independent predictor of survival . CONCLUSION After D1 surgery , the addition of postoperative CRT had a major impact on local recurrence in resectable gastric cancer INTRODUCTION Worldwide , gastric cancer remains one of the most common malignancies . Discouraging survival rates after surgical treatment promote the study of adjuvant therapy . A prospect ively , r and omized , controlled clinical trial was performed in order to determine whether pre-operative and intraoperative radiotherapy improves treatment results of gastrectomy for stomach carcinoma . METHODS From 1993 to 1998 , 112 patients were r and omized and underwent exploratory laparotomy ; among them 78 satisfied protocol requirements and entered in the trial . Patients in the experimental group were treated with pre-operative radiotherapy ( 20 Gy/5 days ) , gastrectomy and intraoperative radiotherapy ( 20 Gy using 8 - 12 electrons ) . Patients in the control group underwent surgery alone . RESULTS Incidence and distribution of post-operative complications were similar in both groups except significantly higher incidence of pancreatitis after surgical treatment . No late radiation-related morbidity was registered . There was no significant difference in survival between the two treatment groups ( Chi(2)=1.026 , df=1 , P=0 . 311 ) as well as in N0 ( Chi(2)=0.0029 , df=1 , P=0.956 ) and T1 - 2 subgroups ( Chi(2)=0.1928 , df=1 , P=0.660 ) . In contrast , combined treatment had marked survival advantage in more advanced stages : in the case of lymph-node involvement ( Chi(2)=4.19 , df=1 , P=0.04 ) and extragastric tumour extension ( Chi(2)=4.118 , df=1 , P=0.042 ) . CONCLUSION The proposed intensive treatment programme is feasible , shows good acute and late tolerance and has the potential to improve survival in patients with locally advanced gastric cancer PURPOSE Preoperative chemotherapy is an accepted st and ard in the treatment of localized esophagogastric adenocarcinoma . Adding radiation therapy to preoperative chemotherapy appears promising , but its definitive value remains unknown . PATIENTS AND METHODS Patients with locally advanced ( uT3 - 4NXM0 ) adenocarcinoma of the lower esophagus or gastric cardia were r and omly allocated to one of two treatment groups : induction chemotherapy ( 15 weeks ) followed by surgery ( arm A ) ; or chemotherapy ( 12 weeks ) followed by chemoradiotherapy ( 3 weeks ) followed by surgery ( arm B ) . Primary outcome was overall survival time . A total of 354 patients were needed to detect a 10 % increase in 3-year survival from 25 % to 35 % by addition of radiation therapy . The study was prematurely closed due to low accrual . RESULTS The median observation time was 46 months . A total of 126 patients were r and omly assigned and 119 eligible patients were evaluated . The number of patients undergoing complete tumor resection was not different between treatment groups ( 69.5 % v 71.5 % ) . Patients in arm B had a significant higher probability of showing pathologic complete response ( 15.6 % v 2.0 % ) or tumor-free lymph nodes ( 64.4 % v 37.7 % ) at resection . Preoperative radiation therapy improved 3-year survival rate from 27.7 % to 47.4 % ( log-rank P = .07 , hazard ratio adjusted for r and omization strata variables 0.67 , 95 % CI , 0.41 to 1.07 ) . Postoperative mortality was nonsignificantly increased in the chemoradiotherapy group ( 10.2 % v 3.8 % ; P = .26 ) . CONCLUSION Although the study was closed early and statistical significance was not achieved , results point to a survival advantage for preoperative chemoradiotherapy compared with preoperative chemotherapy in adenocarcinomas of the esophagogastric junction BACKGROUND AND PURPOSE The role of postoperative chemoradiotherapy in the treatment of patients with gastric cancer with D2 lymph node curative dissection is not well established . In this study , we compared postoperative intensity-modulated radiotherapy plus chemotherapy ( IMRT-C ) with chemotherapy-only in this patient population . MATERIAL S AND METHODS We r and omly assigned patients with D2 lymph node dissection in gastric cancer to  IMRT-C or chemotherapy-only groups . The adjuvant IMRT-C consisted of 400 mg of fluorouracil per square meter of body-surface area per day plus 20 mg of leucovorin per square meter of body-surface area per day for 5 days , followed by 45 Gy of IMRT for 5 weeks , with fluorouracil and leucovorin on the first 4 and the last 3 days of radiotherapy . Two 5-day cycles of fluorouracil and leucovorin were given 4 weeks after the completion of IMRT . Chemotherapy-only group was given the same chemotherapy regimens as IMRT-C group . RESULTS The median overall survival ( OS ) in the chemotherapy-only group was 48 months , as compared with 58 months in the IMRT-C group ; the hazard ratio for death was 1.24 ( 95 % confidence interval , 0.94 - 1.65 ; P=0.122 ) . IMRT-C was associated with increases in the median duration of recurrence-free survival ( RFS ) ( 36 months vs. 50 months ) , the hazard ratio for recurrence was 1.35 ( 95 % confidence interval , 1.03 - 1.78 ; P=0.029 ) . COX multivariate regression analysis showed that lymph node metastasis and TNM stage were both the independent prognostic factors . Rates of all grade adverse events were similar in the two treatment groups . CONCLUSIONS IMRT-C improved RFS , but did not significantly improve OS among patients with D2 lymph node dissection in gastric cancer . Using IMRT plus chemotherapy was feasible and well tolerated in patients with gastric cancer after D2 resection Sixty-two patients with resectable but poor-prognosis gastric carcinoma were r and omized to either no surgical adjuvant therapy or treatment with 5-fluorouracil ( 15 mg/kg by rapid intravenous injection X 3 ) plus radiation ( 3,750 rad in 24 fractions ) initiated 3 1/2 to six weeks postoperatively . Informed consent was obtained after r and omization and only from the 39 r and omized to treatment . Ten patients refused their treatment assignment . The five-year survival rate for patients r and omized to treatment was 23 % , and for those r and omized to no treatment , 4 % ( P less than .05 ) . Both the survival distributions and the alive-without-recurrence distributions were significantly different for the two groups ( P = .024 ) and favored treatment assignment . When the treatment assignment group was broken down to those patients actually receiving treatment and those refusing , five-year survival rates were : treated , 20 % ; treatment refusal , 30 % ; controls , 4 % ; the three survival distributions were not significantly different . Thirty-nine percent of patients actually treated had a local-regional component of first clinical recurrence compared with 54 % of those who received no treatment . This study does not establish 5-fluorouracil plus radiation  as effective surgical adjuvant therapy  for gastric cancer but suggests this approach as a possible fruitful area for continued research . This study also illustrates the potential problems that may be encountered in interpreting results when patients are r and omized to a study before consent is obtained BACKGROUND Adjuvant chemoradiotherapy does not represent the st and ard of care in patients with resected high-risk gastric cancer ; however , results from phase 2 and r and omized trials suggest improvement in overall survival . We assessed the feasibility and toxic effects of chemoradiotherapy as adjuvant treatment in locally advanced gastric cancer . DESIGN Pilot study . SETTING University hospital . PATIENTS Twenty-nine patients with T4N+ or any TN23 gastric cancer previously treated with potentially curative surgery were enrolled . All 
    Output:
    
We provide a critical , non- systematic review of gastric cancer and discuss the role of perioperative radiation therapy in its treatment