***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 
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    ***EXAMPLES*** 
    Input: In 1973 the observation was published that in patients who had received non specific blood transfusions before kidney transplantation graft survival was improved . An immunosuppressive effect of blood transfusion was suggested . Indeed , modulation on the cellular and humoral immunologic system has been demonstrated during the last decade . But this immunomodulation effect might worsen the prognosis after cancer surgery . Whereas in several experimental studies in animals the negative influence was confirmed , clinical investigations on the other h and are contradictive . In our retrospective study we analysed the follow-up of 273 patients ( 158 men , 115 women ; average age 66 years ) on which we had performed a curative resection of their colorectal carcinoma . 182 patients had received nonspecific r and om blood transfusions .  The survival rate for patients with blood transfusions  was significantly worse in comparison to the non-transfused group ( 43 % versus 73 % , respectively ) . Even when we subdivided our patients into tumor stage , differentiation and localisation , the negative influence of transfused blood was confirmed . We conclude that beside the risk of transmitting hepatitis or HIV the immunosuppressive effect is a strong argument to restrict the indication for blood transfusion After curative resection of colorectal cancer , immediate short-term postoperative intraportal adjuvant chemotherapy reduces the relative risk of recurrence and death in the non-transfused patient significantly , when compared to transfused patients without chemotherapy . This is demonstrated in a multivariate analysis using the Cox model on a group of 469 patients who have been intraoperatively r and omized to receive either intraportal chemotherapy for 7 days or no further treatment .  The transfused patients with chemotherapy and those receiving neither transfusions nor chemotherapy had a relative risk of recurrence and death situated in between the two groups mentioned above , not statistically different from either of them . In the setting of this study , 7 days postoperative intraportal chemotherapy seems particularly effective in the non-transfused patients BACKGROUND Benchmarking transfusion activity may help to eliminate inappropriate use of blood products . The goal of this study was to measure and to compare the current transfusion  practice and to identify predictors of transfusion in public hospitals to develop strategies to optimize transfusion practice s. STUDY DESIGN AND METHODS This was a prospect i ve observational study in 18 r and omly selected public hospitals from April 2004 to February 2005 . Primary outcome measures were the amount of intra- and postoperative blood components transfused and intercenter variability of transfusion rate . Secondary outcome measures were prevalence of preoperative anemia , calculated perioperative blood loss , and lowest measured perioperative hemoglobin ( Hb ) level . RESULTS Adult patients undergoing primary unilateral total hip replacement ( THR , n = 1401 ) , primary unilateral knee replacement ( TKR , n = 1296 ) , hemicolectomy ( HECOC , n = 148 ) , and coronary artery bypass graft ( CABG ) surgery ( n = 777 ) were enrolled . Due to the small number , data of HECOC patients were not fully analyzed . In the remaining procedures , there was a large intercenter variability in the percentage of patients who received transfusions : THR 16 to 85 percent , TKR 12 to 87 percent , and CABG 37 to 63 percent . In the patients who received transfusions , the number of red blood cells ( RBC ) units transfused varied significantly . There was also a considerable intercenter variability in RBC loss . The prevalence of preoperative anemia was 19 percent and identical in both sexes . The incidence of preoperative anemia was three times higher in patients who received transfusions compared to those who did not . CONCLUSION This study demonstrates a high intercenter variability in RBC transfusions and RBC loss in st and ard surgical procedures . Whereas the variability in blood loss remains largely unexplained , the main predictors for allogeneic RBC transfusions are preoperative and nadir Hb and surgical RBC loss The aim of this prospect i ve study was to evaluate if there was a statistical correlation between allogeneic blood transfusion and postoperative infections , and if this could have a dose-dependent pattern . The evaluation was based on multiple logistic and receiver operating characteristics ( ROC ) curve analyses . On hospital admission the following parameters were determined in 267 consecutive patients with colorectal cancer : hemoglobin , serum albumin , serum cholinesterase activity , total iron binding capacity and weight loss . Duration of operation , operative blood loss , amount of transfused blood , Dukes ' cancer stage and occurrence of postoperative infections were also recorded . One hundred and thirty-two patients ( 49.4 % ) were given perioperatively allogeneic blood .  Postoperative infections developed in 47 ( 17.6 % ) patients . Multivariate analysis identified  allogeneic blood transfusion  as the only variable related to the occurrence of postoperative infections ( p < 0.05 ) . ROC curve analysis showed that the risk for the occurrence of infection was significantly higher in patients transfused one unit of blood ( p < 0.01 ) . Moreover , a significant trend between increasing number of transfused blood units and susceptibility to infection was found ( p < 0.00019 ) R and om‐donor blood transfusions are deliberately given before  cadaver renal allografting to improve allograft survival . Since host modifications that improve the outcome of an allograft might be associated with a decreased ability of the host to control cancer growth , the relationship between blood transfusions and the outcome of 146 Dukes ' stages A , B , and C colon cancers treated by resection during the years 1974 to 1979 was studied . It was found that 65 patients ( 45 % ) had been transfused and that at 5 years , overall survival was significantly better in the nontransfused patients compared to the transfused patients ( 0.68 and 0.51 5‐year product limit survival fractions respectively ; P = 0.03 for unadjusted log‐rank comparison of entire survival curves ) . Relative risk of death due to cancer in transfused patients versus nontransfused patients was 2.3 ( P = 0.05 ) when controlled for sex , age , stage , histologic differentiation , cancer location , and preresection hemoglobin level using Cox regression analysis . Thus , blood transfusion appears to be an additional important prognostic variable . The hypothesis suggested but not proven by these data that the outcome for some malignancies may be related to the immunomodulating effects of blood transfusions needs further study . Cancer 55:1195‐1201 , 1985 Clinical studies report reduced recurrence-free survival and increased cancer-related death after surgical treatment for cancer , when peri-operative blood transfusions were given . In this study we collected  transfusion data of 212 patients who participated in a prospect i ve study of two different resection techniques for colorectal cancer . One hundred and fifty-eight patients were transfused and 54 were not . The follow-up period for almost all patients was 5 years . The 5-year survival rate was 52 % both for the transfused patients and the nontransfused patients . For subgroups of patients with Dukes ' B and Dukes ' C tumours no statistically significant differences were found . In the group of patients that were transfused the number of transfusions did not affect survival . In this study we could not confirm the deleterious effect of peri-operative blood transfusions on survival PURPOSE Allogeneic blood transfusions have reportedly been associated with a poor prognosis in patients with curatively resected cancer . To control for immunosuppression induced by a speculatively causal allogeneic blood transfusion , we design ed a r and omized study in which the control group received autologous blood transfusions not related to any condition of immunosuppression . PATIENTS AND METHODS One hundred twenty patients with potentially curative resectable colorectal cancer and the capability to predeposit autologous blood were r and omly selected to receive either  st and ard allogeneic blood transfusion or predeposited autologous blood . RESULTS In curatively resected cancer patients , the number who needed allogeneic blood transfusions  was reduced from 60 % in the allogeneic blood group to 33 % in the autologous blood group ( P = .009 ) . After a median follow-up duration of 22 months ( range , 8 to 48 ) tumor recurrence was observed in 28.9 % of the allogeneic blood group and 16.7 % of the autologous blood group . Life-table analysis established a tendency toward a shorter tumor-free survival for the allogeneic blood group ( log-rank P = .11 ) . The problem with this analysis was the strong association of allogeneic blood transfusions  with tumor recurrence , which interfered in 33 % of patients in the autologous blood group who required additional allogeneic blood transfusions . Multivariate analysis of established risk factors for tumor recurrence and surgery-related variables reflecting potential immunosuppressive conditions showed that only pT stage ( relative risk , 6.61 ; 95 % confidence interval [ CI ] , 1.82 to 23.99 ; P = .004 ) , pN stage ( relative risk , 8.39 ; 95 % CI , 3.15 to 22.33 ; P < .001 ) , and the need for allogeneic blood  ( relative risk , 6.18 ; 95 % CI , 2.20 to 17.37 ; P < .001 ) were independent predictors of tumor recurrence . Subgroup analysis of patients who received a transfusion of < or = 2 U blood found a significantly higher risk of tumor recurrence in the allogeneic blood group ( relative risk , 5.16 ; 95 % CI , 1.13 to 23.62 ; P = .034 ) , which was reduced to borderline significance ( relative risk , 3.54 ; 95 % CI , 0.76 to 16.51 ; P = .107 ) by adjustment for tumor ( T ) and node ( N ) stage . CONCLUSION As indicated by these first results , the blood transfusion modality has a significant effect on tumor recurrence after surgical treatment of colorectal cancer . A change in the practice of blood transfusion might thus potentially surpass the impact of any recent adjuvant treatment strategies The relationship between blood transfusion , disease-free survival , and other potential prognostic factors was prospect ively studied in 339 consecutive patients with colorectal cancer . Admission and discharge hematocrit , Dukes ' stage , and blood loss were significantly related to both blood transfusion and disease-free survival . Using Cox proportional hazards model , however , the association of transfusion with disease-free survival was significant ( p = 0.0196 ) after controlling for age , sex , blood loss , procedure , tumor differentiation , stage , admission hematocrit , duration of surgery , length of the specimen , and tumor size . Dukes ' stage ( p < 0.0001 ) and blood transfusion ( p < 0.0001 ) were the only variables independently related to disease-free survival . Forty per cent ( 44 ) of the 110 patients who received transfusions  developed cancer recurrence , compared with 22 % ( 50 ) of the 229 patients who did not receive blood  ( p < 0.0001 ) . Five-year disease-free survival of the transfused patients was 57 % , compared with 77 % for nontransfuscd patients . Patients who developed recurrence received an average of twice as much blood as patients without recurrence ( 1.26 versus 0.61 units , p = 0.0128 ) . Peri-operative blood transfusion  is a significant independent prognostic factor for colorectal cancer BACKGROUND Previous studies on patients with hip fractures and in patients with colorectal cancer have documented that perioperative transfusion is associated with a significant increase in postoperative infection rate . Therefore , we sought to investigate the incidence of preoperative and postoperative anemia in noncardiac surgical patients and to determine if transfusion is an independent risk factor for infection and adverse outcome postoperatively . METHODS Prospect i ve data from the National Veterans Administration Surgical Quality Improvement Program ( NSQIP ) was collected on 6301 noncardiac surgical patients at the Veterans Affairs Maryl and Healthcare System from 1995 to 2000 . RESULTS The mean age of the study cohort was 61 + /- 13 . Descriptive data revealed 95 % were male , 44 % used tobacco , 19 % were diabetic , 9 % had COPD , 9 % used alcohol , 3 % used steroids , 1.7 % had a diagnosis of cancer , and 1.2 % had ascites . Preoperative anemia ( hematocrit less than 36 ) was found in 33.9 % and postoperative anemia was found in 84.1 % of the study cohort . In the postoperative period , 32.5 % of patients had a hematocrit of 26 - 30 , and 26.5 % had a hematocrit of 21 - 25 . Mean units of blood transfused in the perioperative period ranged from 0.1 + /- 0.9 in patients without anemia to 2.7 + /- 2.9 in those with anemia . Incidence of pneumonia increased from 2.6 to 5 % with increasing degree of anemia . Multiple logistic regression analysis documented that low preoperative hematocrit , low postoperative hematocrit , and increased blood transfusion rates were associated with increased mortality ( P < 0.01 ) , increased postoperative 
    Output:
    
In patients with colorectal cancer ( CRC ) undergoing surgery , ABTs are associated with adverse clinical outcomes , including increased mortality .