***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: Perioperative blood transfusions are reported to be related to cancer recurrence and reduced survival . Different underlying mechanisms have been proposed , and allogeneic leucocytes in transfused blood have been suggested to contribute to this phenomenon OBJECTIVE To investigate the impacts of perioperative blood transfusion on the immune function and prognosis in colorectal cancer ( CC ) patients . METHODS A retrospective analysis was conducted in 1404 CC patients , including 1223 sporadic colorectal cancer ( SCC ) patients and 181 hereditary colorectal cancer ( HCC ) patients . Among them , 701 SCC and 102 HCC patients received perioperative blood transfusion .  The amount of T lymphocyte subsets and natural killer ( NK ) cells was measured . All patients received a 10-year follow-up and relapse , metastasis and curative conditions were recorded . RESULTS In SCC group , mortality , local recurrence and distant metastasis rate of transfused patients were significantly higher than non-transfused patients ( all P < 0.05 ) . In HCC group , mortality was apparently higher in transfused patients than non-transfused patients ( P = 0.002 ) . SCC patients transfused with ≥3 U of blood had significantly higher mortality than patients transfused with <3 U ( P = 0.006 ) . The amount of T lymphocyte subsets and NK cells showed statistical differences before and after perioperative blood transfusion in SCC and HCC patients ( all P < 0.05 ) . Also , there existed statistical differences in CD4+/CD8 + ratio among SCC patients before and after the perioperative blood transfusion ( P < 0.05 ) . CC patients who received perioperative blood transfusion had markedly lower 10-year survival rates as compared with those who did not receive ( both P < 0.05 ) . SCC patients transfused with ≥3 U of blood had remarkably lower survival rates compared with SCC patients transfused with <3 U ( P = 0.002 ) . CONCLUSIONS Perioperative blood transfusion  could impact immune function , increased postoperative mortality , local recurrence rate and distant metastasis rate in CC  patients ; and survival rate of CC patients is negatively related to blood transfusion volume Background : Data from small retrospective studies have argued that perioperative packed red blood cell transfusions may increase the risk of developing metastatic recurrence in cancer patients . This study tests this assumption in a large cohort spanning a decade of operatively treated colon cancer patients . Methods : All patients undergoing primary resection of a colon cancer at a tertiary care center between 2004–2014 ( n = 1,423 ) were included in a retrospective review of a prospect ively maintained data repository . Survival and disease‐free survival were compared and also adjusted in multivariable Cox regression st and ardized for follow‐up , American Society of Anesthesiologists score , age , sex , postoperative chemotherapy , baseline staging , and tumor grade . Results : Of the 1,423 patients , 305 ( 21.4 % ) received a perioperative packed red blood cell transfusion during their index admission . During follow‐up , overall mortality was greater in patients who received perioperative packed red blood cell ( 53.1 % vs 30.9 % ; P < .001 ) ; however , there were no appreciable differences in rates of long‐term distant recurrence ( in patients without baseline metastasis 11.1 % vs 13.9 % ; P = .25 ) , or disease‐specific mortality ( 21.3 % vs 17.3 % ; P = .104 ; without baseline metastasis : 8.6 % vs 8.9 % ; P = .89 ) . Similarly , multivariable Cox regression showed no statistical difference in recurrence ( hazard ratio : 0.83 , 95 % confidence interval , 0.83–1.26 ; P = .38 ) or disease‐specific mortality ( hazard ratio : 1.12 , 95 % confidence interval , 0.83–1.51 ; P = .47 ) . Conclusion : Mortality rates were significantly greater in patients with perioperative packed red blood cell transfusions  , a finding that is backed by a body of evidence that associates perioperative packed red blood cell transfusion with comorbidity and serious illness , but contrary to earlier evidence , findings in our cohort do not support a hypothesis that perioperative perioperative packed red blood cell transfusions have a detrimental effect on recurrence rates of operatively treated colon cancer patients OBJECTIVE To explore the influence of different ways of blood transfusion on the expression levels of interleukins ( IL ) and tumor necrosis factor-α ( TNF-α ) inperi-operative patients with esophageal cancer . MATERIAL S AND METHODS A total of 80 patients with esophageal cancer who underwent radical operations were selected as study patients and r and omly divided into an observation group ( treated with autologous blood transfusion ) and control group ( with homologous blood transfusion ) . Changes of intra-operative indexes and peri-operative blood indexes , from hemoglobin ( Hb ) and hematocrit value ( Hct ) , to levels of inflammatory factors like interleukins-6 ( IL-6 ) , IL-8 , IL-10 and tumor necrosis factor-α ( TNF-α ) were compared . RESULTS Operations for patients in both groups were successfully conducted , and no significant differences in mean surgical duration and intra-operative hemorrhage volume , fluid infusion volume and blood transfusion volume were detected ( p>0.05 ) . Compared with values before surgery , Hb and Hct levels decreased significantly while white blood cell count ( WBC ) increased 1 , 5 and 7 d after operation ( p<0.05 , p<0.01 ) . In addition , WBC was apparently higher in observation group than in control group 5 and 7 d after operation ( p<0.01 ) . Compared with before surgery , in the observation group , levels of IL-6 , IL-8 and IL-10 had no significant differences after operation ( P>0.05 ) , but TNF-α level increased y ( p<0.01 ) , whereas in control group , IL-6 level had no significant difference ( p>0.05 ) , IL-8 level decreased obviously ( p<0.05 ) , IL-10 level increased markedly first and then decreased gradually as time passed but its level remained elevated ( p<0.01 ) , and TNF-α level increased first and then decreased , and there was no significant difference 7 d after operation ( p>0.05 ) . CONCLUSIONS Decreased IL-8 and increased IL-10 levels are two important reasons forimmunosuppression after homologous blood transfusion , whereas autologous blood transfusion can alleviate this while increasing the TNF-α level , which also has potential to improve anti-tumor immunity in the human body The aim of our study was to evaluate the prognostic significance of blood transfusion on recurrence and survival in patients undergoing curative resections for colorectal cancer . Retrospective analysis of prospect ively collected data of patients after elective resections for colorectal cancer between January 2001 and December 2009 was undertaken . The main endpoint was overall survival , disease-free survival , and recurrence rate . These data were evaluated in relation to blood transfusion ( group A , no blood transfusion ; group B , one to two blood transfusions ; group C , three and more blood transfusions ) . A total of 583 patients met the criteria for inclusion in the study . Of these , 132 ( 22.6 % ) patients received blood transfusion in the perioperative period . There were 83 ( 14.2 % ) patients who received one or two blood transfusions and 49 ( 8.4 % ) patients who required three or more transfusions . Patients with three or more transfusions had a significantly worse 5-year overall survival , disease-free survival , and increased incidence of distant recurrences in comparison with the group without transfusion or the group with one or two transfusions . Multivariate analysis showed that the application of three or more blood transfusions is an independent risk factor for overall survival ( P = 0.001 ; HR 2.158 ; 95 % CI 1.370–3.398 ) , disease-free survival ( P < 0.001 ; HR 2.514 ; 95 % CI 1.648–3.836 ) , and the incidence of distant recurrence ( P < 0.001 ; HR 2.902 ; 95 % CI 1.616–5.212 ) . Application of three or more blood transfusions in patients operated for colorectal carcinoma is an adverse prognostic factor . Indications for blood transfusion should be carefully considered not only with regard to the risk of early complications , but also because of the possibility of compromising long-term results The frequency of postoperative infectious complications is significantly increased in patients with colorectal cancer receiving perioperative blood transfusion .  It is still debated , however , whether perioperative blood transfusion alters the incidence of disease recurrence or otherwise affects the prognosis The frequency of infection in 197 patients undergoing elective colorectal surgery and having either no blood transfusion , transfusion with whole blood , or filtered blood free from leucocytes and platelets  was investigated in a prospect i ve r and omized trial . Natural killer cell function was measured before operation and 3 , 7 and 30 days after surgery in 60 consecutive patients . Of the patients 104 required  blood transfusion ; 48 received filtered blood and 56 underwent whole blood transfusion . Postoperative infections developed in 13 patients transfused with whole blood ( 23 per cent , 9.5 per cent confidence interval 13–32 per cent ) , in one patient transfused with blood free from leucocytes and platelets ( 2 per cent , 9.5 per cent confidence interval 0.05–11 per cent ) and in two non‐transfused patients ( 2 per cent , 95 per cent conjidence interval 0.3‐8per cent ) ( P < 0.01 ) . Natural killer cell function was significantly ( P < 0.001 ) impaired up to 30 days after surgery in patients transfused with whole blood . These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery BACKGROUND Blood transfusion might affect long-term mortality by changing immune function and thus potentially increasing the risk of subsequent infections and cancer recurrence . Compared with a restrictive transfusion strategy , a more liberal strategy could reduce cardiac complications by lowering myocardial damage , thereby reducing future deaths from cardiovascular disease . We aim ed to establish the effect of a liberal transfusion strategy on long-term survival compared with a restrictive transfusion strategy . METHODS In the r and omised controlled FOCUS trial , adult patients aged 50 years and older , with a history of or risk factors for cardiovascular disease , and with postoperative haemoglobin concentrations lower than 100 g/L within 3 days of surgery to repair a hip fracture , were eligible for enrolment . Patients were recruited from 47 participating hospitals in the USA and Canada , and eligible participants were r and omly allocated in a 1:1 ratio by a central telephone system to either liberal transfusion in which they received blood transfusion to maintain haemoglobin level at 100 g/L or higher , or restrictive transfusion in which they received blood transfusion when haemoglobin level was lower than 80 g/L or if they had symptoms of anaemia . In this study , we analysed the long-term mortality of patients assigned to the two transfusion strategies , which was a secondary outcome of the FOCUS trial . Long-term mortality was established by linking the study participants to national death registries in the USA and Canada . Treatment assignment was not masked , but investigators who ascertained mortality and cause of death were masked to group assignment . Analyses were by intention to treat . The FOCUS trial is registered with Clinical Trials.gov , number NCT00071032 . FINDINGS Between July 19 , 2004 , and Feb 28 , 2009 , 2016 patients were enrolled and r and omly assigned to the two treatment groups : 1007 to the liberal transfusion strategy and 1009 to the restrictive transfusion strategy . The median duration of follow-up was 3·1 years ( IQR 2·4 - 4·1 years ) , during which 841 ( 42 % ) patients died . Long-term mortality did not differ significantly between the liberal transfusion strategy ( 432 deaths ) and the restrictive transfusion strategy ( 409 deaths ) ( hazard ratio 1·09 [ 95 % CI 0·95 - 1·25 ] ; p=0·21 ) . INTERPRETATION Liberal blood transfusion did not affect mortality compared with a restrictive transfusion strategy in a high-risk group of elderly patients with underlying cardiovascular disease or risk factors . The underlying causes of death did not differ between the trial groups . These findings do not support hypotheses that blood transfusion leads to long-term immunosuppression that is severe enough to affect long-term mortality rate by more than 20 - 25 % or cause of death . FUNDING National Heart , Lung , and Blood Institute Background Allogeneic blood transfusion-induced immunomodulation ( TRIM ) and its adverse effect on the prognosis of patients treated surgically for cancer remain complex and controversial . However , the potential risk associated with allogeneic blood transfusion has heightened interest in the use of autologous blood transfusion . In the present study , the serum concentrations of neopterin , interferon- 
    Output:
    
Conclusion Perioperative transfusion causes a dramatically negative effect on long-term prognosis and increases short-term complications after colorectal cancer surgery