***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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    Input: OBJECTIVE To determine perioperative morbidity , survival , and local failure rates in a large group of consecutive patients with rectal cancer undergoing low anterior resection by multiple surgeons on a specialty service . The primary objective was to assess the surgical complications associated with preoperative radiation sequencing . SUMMARY BACKGROUND DATA The goals in the treatment of rectal cancer are cure , local control , and preservation of sphincter , sexual , and bladder function .  Surgical resection using sharp perimesorectal dissection is important for achieving these goals . The complications and mortality rate of this surgical strategy , particularly in the setting of preoperative chemoradiation , have not been well defined . METHODS There were 1233 patients with primary rectal cancer treated at the authors ' cancer center from 1987 to 1995 . Of these , 681 underwent low anterior resection and /or coloanal anastomosis for primary rectal cancer . The surgical technique used the principles of sharp perimesorectal excision . Morbidity and mortality rates were compared between patients receiving preoperative chemoradiation ( Preop RT , n = 150 ) and those not receiving preoperative chemoradiation ( No Preop RT , n = 531 ) . Recurrence and survival data were determined in patients undergoing curative resection ( n = 583 , 86 % ) among three groups of patients : those receiving Preop RT ( n = 131 ) , those receiving postoperative chemoradiation ( Postop RT , n = 110 ) , and those receiving no radiation therapy ( No RT , n = 342 ) . RESULTS The perioperative mortality rate was 0.6 % ( 4/681 ) . Postoperative complications occurred in 22 % ( 153/681 ) . The operative time , estimated blood loss , and rate of pelvic abscess formation without associated leak were higher in the Preop RT group than the No Preop RT group . However , the overall complication rate , rate of wound infection , anastomotic leak , and length of hospital stay were no different between Preop RT and No Preop RT patients . With a median follow-up of 45.6 months , the overall actuarial 5-year recurrence rate for patients undergoing curative resection ( n = 583 ) was 19 % , with 4 % having local recurrence only , 12 % having distant recurrence , and 3 % having both local and distant recurrence , for an overall local recurrence rate of 7 % . The actuarial 5-year overall survival rate was 81 % ; the disease-free survival rate was 75 % and the local recurrence rate was 10 % . The overall survival rate was similar between Preop RT ( 85 % ) , Postop RT ( 72 % ) , and No RT ( 83 % ) patients ( p = 0.10 ) , whereas the disease-free survival rate was significantly worse for Postop RT ( 65 % ) patients compared with Preop RT ( 79 % ) and No RT ( 77 % ) patients ( p = 0.04 ) . CONCLUSION The use of preoperative chemoradiation results in increased operative time , blood loss , and pelvic abscess formation but does not increase the rate of anastomotic leaks or the length of hospital stay after low anterior resection for rectal cancer . The 5-year actuarial overall survival rate for patients undergoing curative resection exceeded 80 % , with a local recurrence rate of 10 % Aim The st and ard treatment for patients with clinical ly resectable rectal cancer is surgery . Postoperative radiochemotherapy ( RCT ) is recommended for advanced disease ( pT3/4 or pN+ ) . In recent years , encouraging results of pre‐operative radiotherapy have been reported . This prospect i ve r and omized phase‐III‐trial ( CAO/ARO/AIO‐94 ) compares the efficacy of neoadjuvant RCT to st and ard postoperative RCT . We report on the design of the study and first results with regard to toxicity of RCT and postoperative morbidity Introduction Total mesorectal excision ( TME ) with preoperative chemoradiation therapy is an accepted st and ard treatment for low rectal cancer . Although the laparoscopic approach is accepted for the treatment of colon cancer , its value for low rectal cancer is unknown . The purpose of this study was to evaluate whether preoperative chemoradiation therapy exerted an adverse influence on laparoscopic TME for low rectal cancer . Methods We studied 125 consecutive patients who underwent laparoscopic TME for low rectal cancer . Twenty patients with preoperative chemoradiation therapy ( CRT-Lap group ) were compared with 105 patients without chemoradiation therapy ( non-CRT-Lap group ) . Results Operating time in the CRT-Lap group ( 276 min , range 160–390 min ) was no different from that in the non-CRT-Lap group ( 263 min , range 143–456 min ) . The CRT-Lap group had more blood loss during the operation ( 70 vs. 37 ml ) , but mean blood loss was < 100 ml . The distal tumor margin was longer in the CRT-Lap group ( 25.8 vs. 18.6 mm ) . The number of lymph node harvested did not differ between the groups ( 14.5 vs. 15.4 ) . Conversion to open surgery was necessary only in one case in the non-CRT-Lap group . There was no anastomotic leakage in the CRT-Lap group , whereas three patients ( 3.1 % ) had anastomotic leakage in the non-CRT-Lap group . Conclusion Laparoscopic TME with preoperative chemoradiation therapy is a safe procedure with reasonable operating time and does not appear to pose any threat to the surgical and oncologic outcomes Summary Background Preoperative or postoperative radiotherapy reduces the risk of local recurrence in patients with operable rectal cancer . However , improvements in surgery and histopathological assessment mean that the role of radiotherapy needs to be reassessed . We compared short-course preoperative radiotherapy versus initial surgery with selective postoperative chemoradiotherapy . Methods We undertook a r and omised trial in 80 centres in four countries . 1350 patients with operable adenocarcinoma of the rectum were r and omly assigned , by a minimisation procedure , to short-course preoperative radiotherapy ( 25 Gy in five fractions ; n=674 ) or to initial surgery with selective postoperative chemoradiotherapy ( 45 Gy in 25 fractions with concurrent 5-fluorouracil ) restricted to patients with involvement of the circumferential resection margin ( n=676 ) . The primary outcome measure was local recurrence . Analysis was by intention to treat . This study is registered , number IS RCT N 28785842 . Findings At the time of analysis , which included all participants , 330 patients had died ( 157 preoperative radiotherapy group vs 173 selective postoperative chemoradiotherapy ) , and median follow-up of surviving patients was 4 years . 99 patients had developed local recurrence ( 27 preoperative radiotherapy vs 72 selective postoperative chemoradiotherapy ) . We noted a reduction of 61 % in the relative risk of local recurrence for patients receiving preoperative radiotherapy ( hazard ratio [ HR ] 0·39 , 95 % CI 0·27–0·58 , p<0·0001 ) , and an absolute difference at 3 years of 6·2 % ( 95 % CI 5·3–7·1 ) ( 4·4 % preoperative radiotherapy vs 10·6 % selective postoperative chemoradiotherapy ) . We recorded a relative improvement in disease-free survival of 24 % for patients receiving preoperative radiotherapy ( HR 0·76 , 95 % CI 0·62–0·94 , p=0·013 ) , and an absolute difference at 3 years of 6·0 % ( 95 % CI 5·3–6·8 ) ( 77·5 % vs 71·5 % ) . Overall survival did not differ between the groups ( HR 0·91 , 95 % CI 0·73–1·13 , p=0·40 ) . Interpretation Taken with results from other r and omised trials , our findings provide convincing and consistent evidence that short-course preoperative radiotherapy is an effective treatment for patients with operable rectal cancer . Funding Medical Research Council ( UK ) and the National Cancer Institute of Canada BACKGROUND In many patients with rectal cancer , defunctioning stomas are created to limit the consequences of anastomotic leakage . Although intended to be temporary , a substantial proportion of these stomas might never be reversed for various reasons . We aim ed to describe stoma policy by use of data from the total mesorectal excision ( TME ) trial in patients with rectal cancer and to identify factors that limit stoma reversal . METHODS 924 Dutch patients with rectal cancer who underwent a low anterior resection were selected from the TME trial , a prospect i ve , r and omised multicentre trial study ing the effects of short-term preoperative radiotherapy in 1861 patients who underwent TME .  Creation of stomas and time to stoma reversal were analysed retrospectively by use of multivariate analysis . FINDINGS In 523 of 924 ( 57 % ) patients , a primary stoma ( defined as a stoma created at the time of TME ) was constructed after a low anterior resection . Geographical differences in the number of primary stomas constructed were reported throughout the Netherl and s. 19 % of stomas that were created were never reversed . Postoperative complications and secondary constructed stomas ( defined as a stoma created during a second or subsequent procedure after TME ) were associated with a high likelihood of a permanent stoma . However , perioperative complications were not a limiting factor for stoma closure . INTERPRETATION Postoperative complications are an important limiting factor for stoma reversal because , after occurrence of these complications , patients and surgeons might be reluctant to reverse the stoma , so a substantial proportion of these stomas are never closed . Future guidelines for stoma creation and closure should consider these factors BACKGROUND We and others have shown that angiogenesis and leukocyte infiltration are important prognostic factors in rectal cancer . However , little is known about its possible changes in response to radiotherapy ( RTX ) , which is frequently given to rectal tumors as a neoadjuvant treatment to improve the prognosis . We therefore investigated the biologic effects of RTX on these parameters using fresh-frozen biopsy sample s of tumor and normal mucosa tissue before and after RTX . METHODS Biopsy sample s were taken from a total of 34 patients before and after either a short course or long course of RTX combined with chemotherapy .  The following parameters were analyzed by immunohistochemistry , flow cytometry , or quantitative real-time polymerase chain reaction : Microvessel density , leukocyte infiltration , proliferating epithelial and tumor cells , proliferating endothelial cells , adhesion molecule expression on endothelial cells , and the angiogenic mRNA profile . RESULTS The tumor biopsy sample s taken after RTX treatment demonstrated a significant decrease in microvessel density and the number of proliferating tumor cells and proliferating endothelial cells ( p < 0.001 ) . In contrast , the leukocyte infiltration , the levels of basic fibroblast growth factor in carcinoma tissue , and the adhesion molecule expression on endothelial cells in normal as well as carcinoma tissue increased significantly ( p < 0.05 ) . CONCLUSION Our data show that together with an overall decrease in tumor cell and endothelial cell proliferation , RTX results in an increase in the expression of adhesion molecules that stimulate leukocyte infiltration . This suggests the possibility that , in addition to its direct cytotoxic effect , radiation may also stimulate an immunologic tumor response that could contribute to the documented improvement in local tumor control and distal failure rate of rectal cancers Although many trials have shown the efficacy of preoperative chemoradiotherapy ( CRT ) or postoperative CRT compared with surgery alone , the optimal sequence of radiotherapy and surgery is unclear . The authors reported the final results of this single institution prospect i ve r and omized phase 3 trial comparing preoperative CRT with postoperative CRT using capecitabine in survival , local control , sphincter preservation , and toxicity for the treatment of locally advanced rectal cancer Purpose This study was undertaken to determine whether neoadjuvant radiotherapy is associated with an increased risk of anastomotic leak for rectal cancer patients undergoing restorative resection . Methods From 1980 to 2010 , patients who underwent restorative resection for rectal cancer ( tumors within 15 cm of anal verge ) were identified from a prospect i ve institutional data base and grouped based on whether they received neoadjuvant radiotherapy ( + RT ) or not ( −RT ) . The main outcome was anastomotic leak documented by imaging ( contrast leak ) , intra-operative or clinical ( signs of peritonitis ) findings and confirmed by staff surgeon assessment . Using multivariate ( MV ) analysis risk factors for leak were identified , presented as OR ( 95 % CI ) . Results One thous and eight hundred sixty-two patients were included in the analysis , 28 % in the + RT group . Eighty-six percent of + RT patients received neoadjuvant chemoradiotherapy .  The overall leak rate was 6.3 % , with no significant difference in + RT and −RT groups ( 8 % vs 5.7 % , p = 0.06 ) . The + RT group had a lower mean age at surgery ( 58 vs 63 year , p < 0.001 ) 
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The interval to surgery after neoadjuvant therapy and preoperative radiotherapy ( short or long course ) was not associated with an increased incidence of postoperative AL .
Conclusion Neoadjuvant therapy does not appear to increase the incidence of postoperative AL  after anterior resection for mid and low rectal cancer .
In addition , neither the interval to surgery after neoadjuvant therapy nor the radiotherapy regimen increases the rate of postoperative AL