***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: Background Conventional abdominoperineal excision ( APE ) of the rectum is associated with higher circumferential resection margin ( CRM ) involvement , increased local recurrence , and reduced survival compared to anterior resection . A more radical extralevator APE ( ELAPE ) technique may improve oncological outcome . However , this technique may confer additional morbidity , and little comparative data on short-term outcomes have been reported . This study compares short-term outcomes and quality of life ( QOL ) after  open and laparoscopic ELAPE , laparoscopic APE ( LAPE ) , and open APE ( OAPE ) .  Methods Data on all ELAPE and 10 consecutive LAPE and OAPE were extracted from a prospect i ve data base . Perioperative care and follow-up were st and ardized . QOL was assessed using EORTC question naires . Results Sixteen ELAPE ( 14 laparoscopic ) , 10 LAPE , and 10 OAPE were included . Demographics , tumour stage , and neoadjuvant therapy use were comparable . Operative time was higher with ELAPE than LAPE and OAPE ( 295 , 207.5 , and 157.5 min , respectively , p = 0.01 ) . A porcine collagen perineal mesh was used in 9 patients undergoing ELAPE  but in no LAPE or OAPE patients . No difference in 30-day complications , re-admission , or length of stay was noted . ELAPE and LAPE were associated with earlier removal of urinary catheter ( p = 0.02 ) , yet other enhanced recovery after surgery ( ERAS ) parameters were equivalent . All ELAPE resections were R0 with no positive CRM identified . One LAPE and 2 OAPE were R1 resections . Analysis revealed no deterioration in QOL with ELAPE , with equivalent global health status . Conclusions The results of this study suggest that ELAPE is not associated with deterioration in short-term outcomes or QOL when compared with LAPE or OAPE PURPOSE : This study was design ed to examine the outcome of cancer of the lower rectum , particularly the rates of local recurrence and survival for tumors located in this area that have been treated by anterior or abdominoperineal resections . METHODS : A prospect i ve , observational , national , cohort study which is part of the Norwegian Rectal Cancer Project . The present cohort includes all patients undergoing total mesorectal excision in 47 hospitals during the period November 1993 to December 1999 . A total of 2,136 patients with rectal cancer within 12 cm of the anal verge were analyzed ; there were 1,315 ( 62 percent ) anterior resections and 821 ( 38 percent ) abdominoperineal resections . The lower edge of the tumor was located 0 to 5 cm from the anal verge in 791 patients , 6 to 8 cm in 558 patients , and 9 to 12 cm in 787 patients . According to the TNM classification , there were 33 percent Stage I , 35 percent Stage II , and 32 percent Stage III . RESULTS : Univariate analyses : The five-year local recurrence rate was 15 percent in the lower level , 13 percent in the intermediate level , and 9 percent in the upper level ( P = 0.014 ) . It was 10 percent local recurrence after anterior resection and 15 percent after abdominoperineal resection ( P = 0.008 ) . The five-year survival rate was 59 percent in the lower level , 62 percent in the intermediate level , and 69 percent in the upper level ( P < 0.001 ) , respectively , and it was 68 percent in the anterior-resection group and 55 percent in the abdominoperineal-resection group ( P < 0.001 ) . Multivariate analyses : The level of the tumor influenced the risk of local recurrence ( hazard ratio , 1.8 ; 95 percent confidence interval , 1.1–2.3 ) , but the operative procedure , anterior resection vs. abdominoperineal resection , did not ( hazard ratio , 1.2 ; 95 percent confidence interval , 0.7–1.8 ) . On the contrary , operative procedure influenced survival ( hazard ratio , 1.3 ; 95 percent confidence interval , 1–1.6 ) , but tumor level did not ( hazard ratio , 1.1 ; 95 percent confidence interval , 0.9–1.5 ) . In addition to patient and tumor characteristics ( T4 tumors ) , intraoperative bowel perforation and tumor involvement of the circumferential margin were identified as significant prognostic factors , which were more common in the lower rectum , explaining the inferior prognosis for tumors in this region . CONCLUSIONS : T4 tumors , R1 resections , and /or intraoperative perforation of the tumor or bowel wall are main features of low rectal cancers , causing inferior oncologic outcomes for tumors in this area . If surgery is optimized , preventing intraoperative perforation and involvement of the circumferential resection margin , the prognosis for cancers of the lower rectum seems not to be inherently different from that for tumors at higher levels . In that case , the level of the tumor or the type of resection will not be indicators for selecting patients for radiotherapy PURPOSE Despite the major improvements that have been made due to total mesorectal excision ( TME ) , low rectal cancer still remains a challenge . METHODS By investigating a prospect i ve r and omized rectal cancer trial in which surgeons had undergone training in  TME  the factors responsible for the poor outcome were determined and a new method for assessing the quality of surgery was tested . RESULTS Survival differed greatly between abdominoperineal resection ( APR ) and anterior resection ( AR ; 38.5 % v 57.6 % , P = .008 ) . Low rectal carcinomas have a higher frequency of circumferential margin involvement ( 26.5 % v 12.6 % , P < .001 ) . More positive margins were present in the patients operated with APR ( 30.4 % ) compared to AR ( 10.7 % , P = .002 ) . Furthermore , more perforations were present in these specimens ( 13.7 % v 2.5 % , P < .001 ) . The plane of resection lies within the sphincteric muscle , the submucosa or lumen in more than 1/3 of the APR cases , and in the remainder lay on the sphincteric muscles . CONCLUSION We systematic ally described and investigated the pathologic properties of low rectal cancer in general , and APR in particular , in a prospect i ve r and omized trial including surgeons who had been trained in TME . The poor prognosis of the patients with an APR  is ascribed to the resection plane of the operation leading to a high frequency of margin involvement by tumor and perforation with this current surgical technique . The clinical results of this operation could be greatly improved by adopting different surgical techniques and possibly greater use of radiochemotherapy BACKGROUND AND PURPOSE During the first decade of the 21st century a number of important European r and omized studies were published . In order to help shape clinical practice based on best scientific evidence from the literature , the International Conference on ' Multidisciplinary Rectal Cancer Treatment : Looking for an European Consensus ' ( EURECA-CC2 ) was organized in Italy under the endorsement of European Society of Medical Oncology ( ESMO ) , European Society of Surgical Oncology ( ESSO ) , and European Society of Therapeutic Radiation Oncology ( ESTRO ) . METHODS Consensus was achieved using the Delphi method . The document was available to all Committee members as a web-based document customized for the consensus process . Eight chapters were identified : epidemiology , diagnostics , pathology , surgery , radiotherapy and chemotherapy , treatment toxicity and quality of life , follow-up , and research questions . Each chapter was subdivided by a topic , and a series of statements were developed . Each member commented and voted , sentence by sentence thrice . Sentences upon which an agreement was not reached after voting round # 2 were openly debated during a Consensus Conference in Perugia ( Italy ) from 11 December to 13 December 2008 . A h and -held televoting system collected the opinions of both the Committee members and the audience after each debate . The Executive Committee scored percentage consensus based on three categories : " large consensus " , " moderate consensus " , and " minimum consensus " . RESULTS The total number of the voted sentences was 207 . Of the 207 , 86 % achieved large consensus , 13 % achieved moderate consensus , and only 3 ( 1 % ) result ed in minimum consensus . No statement was disagreed by more than 50 % of the members . All chapters were voted on by at least 75 % of the members , and the majority was voted on by > 85 % . CONCLUSIONS This Consensus Conference represents an expertise opinion process that may help shape future programs , investigational protocol s , and guidelines for staging and treatment of rectal cancer throughout Europe Local recurrence after resection for rectal cancer remains common despite growing acceptance that inadequate local excision may be implicated . In a prospect i ve study of 190 patients with rectal cancer , we examined the circumferential margin of excision of resected specimens for tumour presence , to examine its frequency and its relation to subsequent local recurrence . Tumour involvement of the circumferential margin was seen in 25 % ( 35/141 ) of specimens for which the surgeon thought the resection was potentially curative , and in 36 % ( 69/190 ) of all cases . After a median 5 years ' follow-up ( range 3.0 - 7.7 years ) , the frequency of local recurrence after potentially curative resection was 25 % ( 95 % CI 18 - 33 % ) . The frequency of local recurrence was significantly higher for patients who had had tumour involvement of the circumferential margin than for those without such involvement ( 78 [ 95 % CI 62 - 94 ] vs 10 [4 - 16]% ) . By Cox 's regression analysis tumour involvement of the circumferential margin independently influenced both local recurrence ( hazard ratio = 12.2 [ 4.4 - 34.6 ] ) and survival ( 3.2 [ 1.6 - 6.53 ] ) . These results show the importance of wide local excision during resection for rectal cancer , and the need for routine assessment of the circumferential margin to assess prognosis BACKGROUND An alternative treatment for low rectal cancer is the cylindrical technique . We aim to compare the outcomes of patients undergoing conventional abdominoperineal resection ( APR ) versus cylindrical APR .  METHODS A prospect i ve , r and omized , open-label , parallel controlled trial was conducted between January 2008 and December 2010 . Sixty-seven patients with T3-T4 low rectal cancer were identified during the study period ( conventional n = 32 , cylindrical n = 35 ) . RESULTS Patients who received cylindrical APR had less operative time for the perineal portion ( P < .001 ) , larger perineal defect ( P < .001 ) , less intraoperative blood loss ( P = .001 ) , larger total cross-sectional tissue area ( P < .001 ) , similar total operative time ( P = .096 ) , and more incidence of perineal pain ( P < .001 ) . The local recurrence of the cylindrical APR group was improved statistically ( P = .048 ) . CONCLUSIONS Cylindrical APR in the prone jackknife position has the potential to reduce the risk of local recurrence without increased complications when compared with conventional APR in the lithotomy position for the treatment of low rectal cancer 5Although electronic search ing and publishing have made it easier to identify and obtain a report of a single r and omised trial , this can not be deemed a short-cut to obtaining an overall , balanced view of the effectiveness of the interventions investigated in the trial . Instead , similar trials need to be brought together . This bringing together needs to be done in as unbiased a way as possible . Traditional narrative review s , usually written by a recognised expert , are generally not systematic . Authors might simply not have the time to identify and bring together all relevant studies or they might actually seek to discuss and selectively combine trials that confirm their opinions and prejudices . A systematic review aims to circumvent this weakness by the use of a predefined , explicit methodology . The methods used include steps to minimise bias in the identification of relevant studies , in the selection criteria for inclusion , and in the collection of data . Guidance is available on the conduct , 
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Conclusion ELAPE has a lower intraoperative bowel perforation rate , positive CRM rate , and local recurrence rate than APE .
There is evidence that in selected low rectal cancer patients , ELAPE is a more efficient and equally safe option to replace APE .