***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: The role of the spleen in tumor immunology is still controversial in that it can either enhance or suppress the antitumor immune response depending on the tumor-bearing host . To clarify this biphasic effect of the spleen , a clinical evaluation of splenectomy in conjunction with immunotherapy and the host immune status was performed in gastric cancer patients . The effect of splenectomy and immunotherapy in 253 gastric cancer patients enrolled in a prospect i ve r and omized trial ( SIP ) was analyzed using the Cox ’s proportional hazards model in terms of the covariate interaction of the preoperative immunosuppressive acidic protein ( IAP ) level . In patients with high IAP levels ( > 580 μg/ml ) with predicted negative antitumor immune reactions splenectomy improved the prognosis . In patients with lower IAP values , conversely , the preservation of the spleen and immunotherapy demonstrated a significant benefit to survival . The spleen was shown to have a biphasic activity in terms of its antitumor immune response depending on the IAP level of the patient . The effect of immunotherapy is significantly influenced by the activity of spleen cells . The preoperative IAP level is therefore considered to be a possible indicator for the effectiveness of splenectomy and immunotherapy in curatively resected gastric cancer patients The following treatments show promise but are as yet to be established as st and ard . They should be prospect ively evaluated in appropriate clinical research setting s. Patient consent for investigational treatments should be sought and the rationale behind them given ( Refer to the Sect . 6 ‘ ‘ Commentary on investigational treatments ’ ’ for details ) . The following constitute investigational treatments : – Endoscopic submucosal dissection under exp and ed criteria – Laparoscopic gastrectomy – Local tumor resection – Neoadjuvant chemotherapy – Adjuvant chemotherapy using agents other than S-1 – Neoadjuvant chemoradiotherapy – Adjuvant chemoradiotherapy – Debulking surgery To compare the outcomes after D1 gastrectomy with those after modified D2 gastrectomy ( preserving pancreas and spleen ) performed by specialist surgeons for gastric cancer in a large UK NHS Trust . In all , 118 consecutive patients with gastric adenocarcinoma were referred by postcode , to undergo either a D1 gastrectomy  ( North Gwent ( RJ ) , n=36 , median age 76 years , 21 m ) or a modified D2 gastrectomy  ( South Gwent ( WL ) , n=82 , 70 years , 57 m ) . Operative mortality in the two groups of patients was similar ( D1 8.3 % vs D2 7.3 % , χ2 0.286 , DF 1 , P=0.593 ) . Overall cumulative survival at 5 years was 32 % after D1 gastrectomy compared to 59 % after D2 gastrectomy ( χ2 4.25 , DF 1 , P=0.0392 ) . In patients with stage III cancers  , survival was 8 % after D1 , compared with 33 % after D2 gastrectomy ( χ2 6.43 , DF 1 , P=0.0112 ) . In a multivariate analysis , T stage ( hazard ratio 2.339 , 95 % CI 1.683–2.995 , P=0.01 ) , N stage ( hazard ratio 4.026 , 95 % CI 3.536–4.516 , P=0.0001 ) and the extent of lymphadenectomy ( hazard ratio 0.258 , 95 % CI –0.426–0.942 , P=0.0001 ) were independently associated with duration s of survival . In conclusion , modified D2 gastrectomy  can improve survival four-fold for patients with stage III gastric cancer , without significantly increasing morbidity and mortality when compared with a D1 gastrectomy BACKGROUND In Japan the surgical approach to treatment of potentially curable gastric cancer , including extended lymphadenectomy , seems in retrospective surveys to give better results than the less radical procedures favoured in Western countries . There has , however , been no evidence from r and omised trials that extended lymphadenectomy ( D2 gastric resection ) confers a survival advantage . This question was addressed in a trial involving thirty-two surgeons in Europe . METHODS In a prospect i ve r and omised controlled trial , D1 resection ( level 1 lymphadenectomy ) was compared with D2 resection ( levels 1 and 2 lymphadenectomy ) . Central r and omisation ( 200 patients in each arm ) followed a staging laparotomy . FINDINGS The D2 group had greater postoperative hospital mortality ( 13 % vs 6.5 % ; p=0.04 [ 95 % Cl 9 - 18 % for D2 , 4 - 11 % for D1 ] and higher overall postoperative morbidity ( 46 % vs 28 % ; p<0.001 ) ; their postoperative stay was also longer . The excess postoperative morbidity and mortality in the D2 group was accounted for by distal pancreaticosplenectomy and splenectomy . In the whole group ( 400 patients ) , survival beyond three years was 30 % in patients whose gastrectomy included en-bloc pancreatico-splenic resection versus 50 % in the remainder . INTERPRETATION D2 gastric resections are followed by higher morbidity and mortality than D1 resections . These disadvantages are consequent upon additional pancreatectomies and distal splenectomies , and in long-term follow-up the higher mortality when the pancreas and spleen are resected may prove to nullify any survival benefit from D2 procedures BACKGROUND / AIMS This study was conducted to clarify the impact of pancreaticosplenectomy on the prognosis of patients with gastric carcinoma . METHODOLOGY Two hundred and seventy-two patients who underwent total gastrectomy with distal pancreatectomy and splenectomy  were retrospectively review ed . RESULTS Lymph node metastases at the splenic hilum ( # 10 ) and along the splenic artery ( # 11 ) occurred in 12.4 % and 19.2 % of cases , respectively . The 5-year survival rate of those without metastasis at # 10 was 62.8 % . Once nodal metastasis occurred , the prognosis became very poor ; only 18.2 % in those with a single positive node and 15.4 % of those with two or more positive nodes at this location survived 5 years . Similar trends in survival were observed with respect to nodes at # 11 . When stratified by nodal status as currently determined by microscopic examination , pancreaticosplenectomy saved 4.5 % of patients with positive nodes , but was insufficient in 17.3 % of cases and was not necessary in the 78.2 % of cases who were node negative at these locations . CONCLUSIONS The data indicate that pancreaticosplenectomy can save some patients with positive nodes in these regions ; however , the small survival benefit does not provide a basis for the general application of this highly morbid procedure . To further evaluate these results in a r and omized study , selection of a subset of patients who are likely to have metastasis is the key BACKGROUND Complete surgical ( R0 ) resection remains the only potentially curative intervention for patients with localised gastric cancer . To achieve a curative resection , patients may require complex operations with resection of contiguous organs . The aim of this study was to assess how the extent of surgical resection influenced morbidity , mortality and survival in an aged non-selected population with significant comorbid disease . PATIENTS AND METHODS Data were extracted from the Scottish Audit of Gastric and Oesophageal Cancer ( SAGOC ) , a prospect i ve population -based audit of all oesophageal and gastric cancers in Scotl and between 1997 and 1999 with a minimum of 1-year follow-up . RESULTS A total of 646 patients underwent surgical exploration for gastric cancer . A significantly higher incidence of chest infections ( 18.5 vs 11 % , p < 0.05 ) and anastomotic leaks ( 14.3 vs 2.2 % , p < 0.05 ) were associated with total gastrectomy ( n=168 ) when compared to distal gastrectomy ( n=272 ) resections . A 9.2 % mortality rate and a 60 % 1-year survival were associated with gastric resection alone . Removal of the spleen ( n=131 ) , pancreas ( n=30 ) or liver resection ( n=5 ) was associated with a significantly higher mortality rates , 18.3 , 23.3 and 40 % , respectively ( p < 0.05 ) , and significantly lower 1-year survival rates , 50.9 , 39.1 and 20 % , respectively ( p < 0.05 ) . CONCLUSIONS The risk of more extensive resection is not balanced by improved survival in this population based series . Extending gastric resection to involve contiguous organs should be confined to highly selected cases Extended  lymphadenectomy for gastric carcinoma has been associated with high mortality and morbidity rates in several multicentre r and omized trials BACKGROUND Historical data and recent studies show that st and ardised extended ( D2 ) lymphadenectomy leads to better results than st and ardised limited ( D1 ) lymphadenectomy . Based on these findings , the Dutch D1D2 trial , a nationwide prospect ively r and omised clinical trial , was undertaken to compare D2 with D1 lymphadenectomy in patients with resectable primary adenocarcinoma of the stomach . The aim of the study was to assess the effect of D2 compared with D1 surgery on disease recurrence and survival in patients treated with curative intent . METHODS Between August , 1989 , and July , 1993 , patients were entered and r and omised at 80 participating hospitals by means of a telephone call to the central data centre of the trial . The sequence of r and omisation was in blocks of six with stratification for the participating centre . Eligibility criteria were a histologically proven adenocarcinoma of the stomach without evidence of distance metastasis , age younger than 85 years , and adequate physical condition for D1 or D2 lymphadenectomy . Patients were excluded if they had previous or coexisting cancer or had undergone gastrectomy for benign tumours . Strict quality control measures for pathological assessment were implemented and monitored . Analyses were by intention to treat . This study is registered with the NCI trial register , as DUT-KWF-CKVO-8905 , EU-90003 . FINDINGS A total of 1078 patients were entered in the study , of whom 996 were eligible . 711 patients underwent the r and omly assigned treatment with curative intent ( 380 in the D1 group and 331 in the D2 group ) and 285 had palliative treatment . Data were collected prospect ively and all patients were followed up for a median time of 15.2 years ( range 6.9 - 17.9 years ) . Analyses were done for the 711 patients treated with curative intent and were according to the allocated treatment group . Of the 711 patients , 174 ( 25 % ) were alive , all but one without recurrence . Overall 15-year survival was 21 % ( 82 patients ) for the D1 group and 29 % ( 92 patients ) for the D2 group ( p=0.34 ) . Gastric-cancer-related death rate was significantly higher in the D1 group ( 48 % , 182 patients ) compared with the D2 group ( 37 % , 123 patients ) , whereas death due to other diseases was similar in both groups . Local recurrence was 22 % ( 82 patients ) in the D1 group versus 12 % ( 40 patients ) in D2 , and regional recurrence was 19 % ( 73 patients ) in D1 versus 13 % ( 43 patients ) in D2 . Patients who had the D2 procedure had a significantly higher operative mortality rate than those who had D1 ( n=32 [ 10 % ] vs n=15 [ 4 % ] ; 95 % CI for the difference 2 - 9 ; p=0.004 ) , higher complication rate ( n=142 [ 43 % ] vs n=94 [ 25 % ] ; 11 - 25 ; p<0.0001 ) , and higher reoperation rate ( n=59 [ 18 % ] vs n=30 [ 8 % ] ; 5 - 15 ; p=0.00016 ) . INTERPRETATION After a median follow-up of 15 years , D2 lymphadenectomy is associated with lower locoregional recurrence and gastric-cancer-related death rates than D1 surgery . The D2 procedure was also associated with significantly higher postoperative mortality , morbidity , and reoperation rates . Because a safer , spleen-preserving D2 resection technique is currently available in high-volume centres , D2 lymphadenectomy is the recommended surgical approach for patients with resectable ( curable ) gastric cancer . FUNDING Dutch Health Insurance Funds Council and The Netherl and s Cancer Foundation BACKGROUND Resection of the spleen en bloc with the stomach for gastric cancer is still widely performed for a curative resection ( R0 ) , but the presence of the spleen may have a favorable effect on recurrence control and surv 
    Output:
    
Conclusions Preservation of the spleen and pancreas during extended lymphadenectomy for gastric cancer decreases complications with no clear evidence of improvement or detriment to overall survival