human
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose Deterioration of anorectal function after long-course preoperative chemoradiotherapy combined with surgery for rectal cancer is poorly defined . We conducted a prospect i ve study to evaluate the acute and long term effects of preoperative chemoradiotherapy on anorectal function and quality of life of the patients . Methods There were 26 patients in surgery group and 31 patients in preoperative chemoradiotherapy group .  Anorectal function and quality of life of the patients were assessed by anorectal manometry , incontinence score , quality of life question naire . Results Significant lower resting pressures in both groups and lower maximal squeeze pressures in the preoperative chemoradiotherapy group were observed after postsurgical evaluations compared with the paired pretreatment ones . In the surgery group , both the Wexner continence score , FIQL score , and the rectoscopy score were comparable before and after surgery , whereas significant worsening in the Wexner score was observed in the preoperative chemoradiotherapy group postoperatively ( P < 0.01 ) . Significant reduction in anal canal resting pressures and squeeze pressures , Wexner score , and FIQL score were observed immediately after the completion of preoperative chemoradiotherapy . Significant lower maximal squeeze pressures and worsening of the Wexner scores were observed in the preoperative chemoradiotherapy group compared to the surgery group during the postoperative assessment s ( P < 0.05 and P < 0.01 , respectively ) . Conclusions Both total mesorectal excision and preoperative chemoradiotherapy may adversely affect the anorectal function . Careful selection of the patients who will benefit from neoadjuvant therapy and identifying the patients with a high risk of developing functional problems may help to improve functional outcomes for the treatment of rectal cancer Faced with the responsibility of treating patients with invasive distal rectal cancer who were medically unacceptable for the indicated radical surgery  , a prospect i ve study was initiated in which high dose preoperative radiation and full-thickness local excision were used . High dose preoperative radiation permitted full-thickness local excision of select cancers , which , by conventional st and ards , otherwise would have required radical surgery and permanent colostomy . Feasibility was measured on the basis of safety of the technique , control of the cancer , and the quality of anal sphincter function expected . Patients were selected initially because of their predicted inability to tolerate radical surgery , but indications were broadened to include those whose tumors had completely disappeared after irradiation . From 1984 to 1988 , 20 patients underwent 21 operative procedures for cancers located between 0 and 7 cm from the anorectal ring . This report is concerned with the 14 patients of this group who were observed for a minimum of 24 months .  High-dose preoperative radiation was administered for a total dose of 4500 cGy . Excision and repair were performed 4 to 6 weeks after completion of radiation therapy . Full-thickness disc or hemicircumferential excision was accomplished by transanal , transsphincteric , and transsacral techniques , which included , in several instances , excision of the sphincter mechanism and perineal body , and /or the vaginal wall . Full-thickness local excision after high-dose radiation therapy for rectal cancers has never been reported . Follow-up observation ranged from 24 to 48 months with a median of 31 months . Rectal reservoir function and sphincter control were good in 13 patients .  Local recurrence developed in three patients ( 21 percent ) , two of whom had postradiation therapy B2 mucinous cancers .  Three-year actuarial rate of local recurrence is 23 percent . One ( 7 percent ) patient died of recurrent disease . Actuarial Kaplan-Meier survival at 3 years is 61 percent . Based on the results of this small , select patient group , high-dose radiation therapy followed by full-thickness local excision appears to be a reasonable option for patients who can not tolerate radical surgery . This bimodal approach also may serve as an option for those who aregoodmedical risks , but for whom sphincter preservation is at stake , and to whom radical surgery offers limited benefits Background Neoadjuvant therapies have significantly improved local control and survival of patients with rectal cancer . Nevertheless , although a complete pathologic response can be achieved in 30 % of cases , a transabdominal surgical resection is always required . This study aim ed , for the first time , to test in the literature the feasibility of local excision combined with transanal endoscopic microsurgery ( TEM ) as a surgical option for patients treated with neoadjuvant chemoradiation . Methods Between July 1997 and December 2002 , 30 patients with rectal cancer affected by an extraperitoneal tumor entered a protocol consisting of neoadjuvant chemoradiation followed by surgery . The surgical treatment , consisting of open surgery , local excision , or TEM , was planned according to the patient ’s clinical response after chemoradiation and distance from the anal verge . Results A significant clinical downstaging was observed in eight patients . Five of these patients underwent TEM , and three had local excision . Consequently , open surgery was performed for 22 patients . Histology showed six cases of complete pathologic response : three in the open surgery group and three in the transanal excision group . After a mean follow-up period of 47 months , the disease-free survival rate was 77 % in the open surgery group and 100 % in TEM or local excision group . Conclusions The findings suggest the complementary feasibility of TEM and local excision after neoadjuvant chemoradiation . However , r and omized trials are needed to confirm the oncologic safety of this approach BACKGROUND Postoperative chemoradiotherapy is the recommended st and ard therapy for patients with locally advanced rectal cancer . In recent years , encouraging results with preoperative radiotherapy have been reported . We compared preoperative chemoradiotherapy with postoperative chemoradiotherapy for locally advanced rectal cancer . METHODS We r and omly assigned patients with clinical stage T3 or T4 or node-positive disease to receive either  preoperative or postoperative chemoradiotherapy . The preoperative treatment consisted of 5040 cGy delivered in fractions of 180 cGy per day , five days per week , and fluorouracil , given in a 120-hour continuous intravenous infusion at a dose of 1000 mg per square meter of body-surface area per day during the first and fifth weeks of radiotherapy . Surgery was performed six weeks after the completion of chemoradiotherapy . One month after surgery , four five-day cycles of fluorouracil ( 500 mg per square meter per day ) were given . Chemoradiotherapy was identical in the postoperative-treatment group , except for the delivery of a boost of 540 cGy . The primary end point was overall survival . RESULTS Four hundred twenty-one patients were r and omly assigned to receive preoperative chemoradiotherapy  and 402 patients to receive postoperative chemoradiotherapy . The overall five-year survival rates were 76 percent and 74 percent , respectively ( P=0.80 ) . The five-year cumulative incidence of local relapse was 6 percent for patients assigned to preoperative chemoradiotherapy and 13 percent in the postoperative-treatment group ( P=0.006 ) . Grade 3 or 4 acute toxic effects occurred in 27 percent of the patients in the preoperative-treatment group , as compared with 40 percent of the patients in the postoperative-treatment group ( P=0.001 ) ; the corresponding rates of long-term toxic effects were 14 percent and 24 percent , respectively ( P=0.01 ) . CONCLUSIONS Preoperative chemoradiotherapy , as compared with postoperative chemoradiotherapy , improved local control and was associated with reduced toxicity but did not improve overall survival BACKGROUND This study was conducted to assess the efficacy of preoperative chemoradiation followed by transanal excision among patients with locally advanced lower rectal cancer . METHODS Between May 1994 and June 2005 , 73 patients with locally advanced lower rectal cancer were treated with curative intent by preoperative chemoradiation followed by surgical resection . Transanal excision was performed in 9 patients due to either the absolute refusal of a permanent stoma by the patient ( n = 8) or medical comorbidity ( n = 1 ) . Sixty-four patients were treated by radical proctectomy . Preoperative 5-fluorouracil-based chemotherapy and pelvic radiation ( 4500 to 5040 cGy ) were followed by surgery 6 wk after treatment , and all patients except one with transanal excision received postoperative 5-fluorouracil-based chemotherapy during the first year after surgery . RESULTS The mean follow-up period was 91 mo ( range , 50 to 127 mo ) ; median follow-up was 94 mo . One local recurrence occurred at 30 mo after transanal excision ( 11.1 % ) ; 5 in 64 patients who received radical proctectomy ( 7.8 % ) experienced local recurrences . The disease-free survival rate at 10 y was 77.8 % in transanal excision group compared with a rate of 62.7 % among radical proctectomy patients ( P = 0.335 ) . The overall survival rate at 10 y was 88.9 % in transanal excision group compared with 74.2 % among radical proctectomy patients ( P = 0.424 ) . CONCLUSIONS Transanal excision after preoperative chemoradiation in highly-selected patients with locally advanced lower rectal cancer could probably be an acceptable alternative to conventional radical surgery . However , this approach should be prospect ively vali date d , and strict patient selection criteria should be used High-dose preoperative radiation with new sphincter-preserving surgical options for the management of distal and unfavorable cancers of the rectum is gaining recognition as an alternative to abdominoperineal resection and permanent colostomy . From 1976 to 1989 , 161 patients with cancer of the rectum were entered into a program of high-dose preoperative radiation and radical sphincter-preserving surgery . Selection was based on prospect i ve clinical staging of unfavorability or tumor location at a low level in the rectum . All patients received a minimum dose of 4,000 to 4,500 cGy over 4 1/2 weeks in fractional doses of 180 to 250 cGy . Patients with tumor fixation were given an additional boost of 1,000 to 1,500 cGy for a total of 5,500 to 6,000 cGy using a coned-down field . Surgery was carried out four to eight weeks following completion of radiation . Fourteen patients , found at surgery to have liver metastasis , were treated by palliative resection . One hundred forty-seven patients underwent radical curative surgery  with  sphincter  preservation . The surgical procedures performed were combined abdominotranssacral resection ( 63 ) , transanal-abdominal-transanal resection ( 53 ) , and anterior resection ( 31 ) . Follow-up ranged from a minimum of two years to 15 years , with a median of five years . There was no perioperative mortality . Anastomotic failure occurred in three patients , two of whom were reconstituted . Late diversion was required in 10 other patients , primarily for recurrent disease . One hundred thirty-four of the 147 patients ( 91 percent ) maintained long-term normal sphincter function . Pelvic-perineal recurrence was observed in 18 patients ( 12.4 percent ) , 12 of whom had fixed tumors located below the 6-cm level of the distal rectum . Median time to local recurrence was 24 months . Distant metastasis with or without local recurrence occurred in 35 patients , 22 of whom had fixed tumors below the 6-cm level of the rectum . Median time to distant metastasis was 17 months . Forty-three patients have died , 32 of disease . The overall five-year Kaplan-Meier actuarial survival for the total group of patients is 79 percent , with a disease-free survival of 73 percent . The findings of this study indicate that high-dose preoperative radiation used in combination with radical sphincter-preserving surgical techniques results in excellent local control of disease , improved survival , and enhanced quality of life with retention of normal anal sphincter function BACKGROUND : Transanal local excision has been suggested as an attractive approach for patients with rectal cancer who show a major clinical response after preoperative chemoradiotherapy . OBJECTIVE : To evaluate the impact of transanal local excision on the local recurrence of rectal cancer in patients who had a major clinical response after preoperative chemoradiotherapy .  DESIGN : Sequential 2-stage phase II study for early efficacy . SETTING : Multicenter study . PATIENTS : Patients with clinical T3 or low-lying T2 rectal adenocarcinoma that showed a major clinical response after a preoperative chemoradiotherapy .  Eligible patients underwent a full-thickness transanal local excision . According to their histopathology , the patients staged as ypT0 - 1 were observed , while the remaining patients were recommended to undergo a subsequent total mesorectal excision . MAIN OUTCOME MEASURES : A local recurrence rate of ⩽5 % was set as a successful rate for stopping the trial early after the first stage . RESULTS : The study group included 63 patients . Before chemoradiotherapy , patients were staged as clinical T3 ( n = 42 ) and T2 ( n = 21 ) . After the local excision , 43 patients fulfilled the criteria to be observed with no further treatment . Nine of the remaining 20 patients for 
    Output:
    
agent
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose Deterioration of anorectal function after long-course preoperative chemoradiotherapy combined with surgery for rectal cancer is poorly defined . We conducted a prospect i ve study to evaluate the acute and long term effects of preoperative chemoradiotherapy on anorectal function and quality of life of the patients . Methods There were 26 patients in surgery group and 31 patients in preoperative chemoradiotherapy group .  Anorectal function and quality of life of the patients were assessed by anorectal manometry , incontinence score , quality of life question naire . Results Significant lower resting pressures in both groups and lower maximal squeeze pressures in the preoperative chemoradiotherapy group were observed after postsurgical evaluations compared with the paired pretreatment ones . In the surgery group , both the Wexner continence score , FIQL score , and the rectoscopy score were comparable before and after surgery , whereas significant worsening in the Wexner score was observed in the preoperative chemoradiotherapy group postoperatively ( P < 0.01 ) . Significant reduction in anal canal resting pressures and squeeze pressures , Wexner score , and FIQL score were observed immediately after the completion of preoperative chemoradiotherapy . Significant lower maximal squeeze pressures and worsening of the Wexner scores were observed in the preoperative chemoradiotherapy group compared to the surgery group during the postoperative assessment s ( P < 0.05 and P < 0.01 , respectively ) . Conclusions Both total mesorectal excision and preoperative chemoradiotherapy may adversely affect the anorectal function . Careful selection of the patients who will benefit from neoadjuvant therapy and identifying the patients with a high risk of developing functional problems may help to improve functional outcomes for the treatment of rectal cancer Faced with the responsibility of treating patients with invasive distal rectal cancer who were medically unacceptable for the indicated radical surgery  , a prospect i ve study was initiated in which high dose preoperative radiation and full-thickness local excision were used . High dose preoperative radiation permitted full-thickness local excision of select cancers , which , by conventional st and ards , otherwise would have required radical surgery and permanent colostomy . Feasibility was measured on the basis of safety of the technique , control of the cancer , and the quality of anal sphincter function expected . Patients were selected initially because of their predicted inability to tolerate radical surgery , but indications were broadened to include those whose tumors had completely disappeared after irradiation . From 1984 to 1988 , 20 patients underwent 21 operative procedures for cancers located between 0 and 7 cm from the anorectal ring . This report is concerned with the 14 patients of this group who were observed for a minimum of 24 months .  High-dose preoperative radiation was administered for a total dose of 4500 cGy . Excision and repair were performed 4 to 6 weeks after completion of radiation therapy . Full-thickness disc or hemicircumferential excision was accomplished by transanal , transsphincteric , and transsacral techniques , which included , in several instances , excision of the sphincter mechanism and perineal body , and /or the vaginal wall . Full-thickness local excision after high-dose radiation therapy for rectal cancers has never been reported . Follow-up observation ranged from 24 to 48 months with a median of 31 months . Rectal reservoir function and sphincter control were good in 13 patients .  Local recurrence developed in three patients ( 21 percent ) , two of whom had postradiation therapy B2 mucinous cancers .  Three-year actuarial rate of local recurrence is 23 percent . One ( 7 percent ) patient died of recurrent disease . Actuarial Kaplan-Meier survival at 3 years is 61 percent . Based on the results of this small , select patient group , high-dose radiation therapy followed by full-thickness local excision appears to be a reasonable option for patients who can not tolerate radical surgery . This bimodal approach also may serve as an option for those who aregoodmedical risks , but for whom sphincter preservation is at stake , and to whom radical surgery offers limited benefits Background Neoadjuvant therapies have significantly improved local control and survival of patients with rectal cancer . Nevertheless , although a complete pathologic response can be achieved in 30 % of cases , a transabdominal surgical resection is always required . This study aim ed , for the first time , to test in the literature the feasibility of local excision combined with transanal endoscopic microsurgery ( TEM ) as a surgical option for patients treated with neoadjuvant chemoradiation . Methods Between July 1997 and December 2002 , 30 patients with rectal cancer affected by an extraperitoneal tumor entered a protocol consisting of neoadjuvant chemoradiation followed by surgery . The surgical treatment , consisting of open surgery , local excision , or TEM , was planned according to the patient ’s clinical response after chemoradiation and distance from the anal verge . Results A significant clinical downstaging was observed in eight patients . Five of these patients underwent TEM , and three had local excision . Consequently , open surgery was performed for 22 patients . Histology showed six cases of complete pathologic response : three in the open surgery group and three in the transanal excision group . After a mean follow-up period of 47 months , the disease-free survival rate was 77 % in the open surgery group and 100 % in TEM or local excision group . Conclusions The findings suggest the complementary feasibility of TEM and local excision after neoadjuvant chemoradiation . However , r and omized trials are needed to confirm the oncologic safety of this approach BACKGROUND Postoperative chemoradiotherapy is the recommended st and ard therapy for patients with locally advanced rectal cancer . In recent years , encouraging results with preoperative radiotherapy have been reported . We compared preoperative chemoradiotherapy with postoperative chemoradiotherapy for locally advanced rectal cancer . METHODS We r and omly assigned patients with clinical stage T3 or T4 or node-positive disease to receive either  preoperative or postoperative chemoradiotherapy . The preoperative treatment consisted of 5040 cGy delivered in fractions of 180 cGy per day , five days per week , and fluorouracil , given in a 120-hour continuous intravenous infusion at a dose of 1000 mg per square meter of body-surface area per day during the first and fifth weeks of radiotherapy . Surgery was performed six weeks after the completion of chemoradiotherapy . One month after surgery , four five-day cycles of fluorouracil ( 500 mg per square meter per day ) were given . Chemoradiotherapy was identical in the postoperative-treatment group , except for the delivery of a boost of 540 cGy . The primary end point was overall survival . RESULTS Four hundred twenty-one patients were r and omly assigned to receive preoperative chemoradiotherapy  and 402 patients to receive postoperative chemoradiotherapy . The overall five-year survival rates were 76 percent and 74 percent , respectively ( P=0.80 ) . The five-year cumulative incidence of local relapse was 6 percent for patients assigned to preoperative chemoradiotherapy and 13 percent in the postoperative-treatment group ( P=0.006 ) . Grade 3 or 4 acute toxic effects occurred in 27 percent of the patients in the preoperative-treatment group , as compared with 40 percent of the patients in the postoperative-treatment group ( P=0.001 ) ; the corresponding rates of long-term toxic effects were 14 percent and 24 percent , respectively ( P=0.01 ) . CONCLUSIONS Preoperative chemoradiotherapy , as compared with postoperative chemoradiotherapy , improved local control and was associated with reduced toxicity but did not improve overall survival BACKGROUND This study was conducted to assess the efficacy of preoperative chemoradiation followed by transanal excision among patients with locally advanced lower rectal cancer . METHODS Between May 1994 and June 2005 , 73 patients with locally advanced lower rectal cancer were treated with curative intent by preoperative chemoradiation followed by surgical resection . Transanal excision was performed in 9 patients due to either the absolute refusal of a permanent stoma by the patient ( n = 8) or medical comorbidity ( n = 1 ) . Sixty-four patients were treated by radical proctectomy . Preoperative 5-fluorouracil-based chemotherapy and pelvic radiation ( 4500 to 5040 cGy ) were followed by surgery 6 wk after treatment , and all patients except one with transanal excision received postoperative 5-fluorouracil-based chemotherapy during the first year after surgery . RESULTS The mean follow-up period was 91 mo ( range , 50 to 127 mo ) ; median follow-up was 94 mo . One local recurrence occurred at 30 mo after transanal excision ( 11.1 % ) ; 5 in 64 patients who received radical proctectomy ( 7.8 % ) experienced local recurrences . The disease-free survival rate at 10 y was 77.8 % in transanal excision group compared with a rate of 62.7 % among radical proctectomy patients ( P = 0.335 ) . The overall survival rate at 10 y was 88.9 % in transanal excision group compared with 74.2 % among radical proctectomy patients ( P = 0.424 ) . CONCLUSIONS Transanal excision after preoperative chemoradiation in highly-selected patients with locally advanced lower rectal cancer could probably be an acceptable alternative to conventional radical surgery . However , this approach should be prospect ively vali date d , and strict patient selection criteria should be used High-dose preoperative radiation with new sphincter-preserving surgical options for the management of distal and unfavorable cancers of the rectum is gaining recognition as an alternative to abdominoperineal resection and permanent colostomy . From 1976 to 1989 , 161 patients with cancer of the rectum were entered into a program of high-dose preoperative radiation and radical sphincter-preserving surgery . Selection was based on prospect i ve clinical staging of unfavorability or tumor location at a low level in the rectum . All patients received a minimum dose of 4,000 to 4,500 cGy over 4 1/2 weeks in fractional doses of 180 to 250 cGy . Patients with tumor fixation were given an additional boost of 1,000 to 1,500 cGy for a total of 5,500 to 6,000 cGy using a coned-down field . Surgery was carried out four to eight weeks following completion of radiation . Fourteen patients , found at surgery to have liver metastasis , were treated by palliative resection . One hundred forty-seven patients underwent radical curative surgery  with  sphincter  preservation . The surgical procedures performed were combined abdominotranssacral resection ( 63 ) , transanal-abdominal-transanal resection ( 53 ) , and anterior resection ( 31 ) . Follow-up ranged from a minimum of two years to 15 years , with a median of five years . There was no perioperative mortality . Anastomotic failure occurred in three patients , two of whom were reconstituted . Late diversion was required in 10 other patients , primarily for recurrent disease . One hundred thirty-four of the 147 patients ( 91 percent ) maintained long-term normal sphincter function . Pelvic-perineal recurrence was observed in 18 patients ( 12.4 percent ) , 12 of whom had fixed tumors located below the 6-cm level of the distal rectum . Median time to local recurrence was 24 months . Distant metastasis with or without local recurrence occurred in 35 patients , 22 of whom had fixed tumors below the 6-cm level of the rectum . Median time to distant metastasis was 17 months . Forty-three patients have died , 32 of disease . The overall five-year Kaplan-Meier actuarial survival for the total group of patients is 79 percent , with a disease-free survival of 73 percent . The findings of this study indicate that high-dose preoperative radiation used in combination with radical sphincter-preserving surgical techniques results in excellent local control of disease , improved survival , and enhanced quality of life with retention of normal anal sphincter function BACKGROUND : Transanal local excision has been suggested as an attractive approach for patients with rectal cancer who show a major clinical response after preoperative chemoradiotherapy . OBJECTIVE : To evaluate the impact of transanal local excision on the local recurrence of rectal cancer in patients who had a major clinical response after preoperative chemoradiotherapy .  DESIGN : Sequential 2-stage phase II study for early efficacy . SETTING : Multicenter study . PATIENTS : Patients with clinical T3 or low-lying T2 rectal adenocarcinoma that showed a major clinical response after a preoperative chemoradiotherapy .  Eligible patients underwent a full-thickness transanal local excision . According to their histopathology , the patients staged as ypT0 - 1 were observed , while the remaining patients were recommended to undergo a subsequent total mesorectal excision . MAIN OUTCOME MEASURES : A local recurrence rate of ⩽5 % was set as a successful rate for stopping the trial early after the first stage . RESULTS : The study group included 63 patients . Before chemoradiotherapy , patients were staged as clinical T3 ( n = 42 ) and T2 ( n = 21 ) . After the local excision , 43 patients fulfilled the criteria to be observed with no further treatment . Nine of the remaining 20 patients for 
    Output:
    