***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: All 68,308 inhabitants of Göteborg born between 1918 and 1931 were r and omly divided into a test and a control group . The subjects in the test group were invited to perform Hemoccult II fecal occult blood testing  on 3 days and to repeat the test after 16 to 24 months . In the prevalence screening 21,347 ( 63 % ) performed the test , and in the rescreening 19,991 ( 60 % ) . Investigation of the 942 ( 4.4 % ) with positive tests in the prevalence screening showed 47 cancers and 129 subjects with adenomas > or = 1.0 cm . In the rescreening 5.1 % had a positive test , and 34 cancers and 122 subjects with adenomas ( > or = 1.0 cm ) were found among those . Cancer had also been diagnosed in 19 subjects in the interval between the two screening occasions and in 15 subjects among the non-responders . Forty-four cancers had been diagnosed in the control group during the same period . Cancers detected by screening were at a less advanced stage than in the control group . It is too early to show any effect of  screening  on mortality from colorectal cancer BACKGROUND Although tests for occult blood in the feces are widely used to screen for colorectal cancers , there is no conclusive evidence that they reduce mortality from this cause . We evaluated a fecal occult-blood test  in a r and omized trial and documented its effectiveness . METHODS We r and omly assigned 46,551 participants 50 to 80 years of age to screening for colorectal cancer once a year , to  screening every two years , or to a control group .  Participants who were screened su bmi tted six guaiac-impregnated paper slides with two smears from each of three consecutive stools . About 83 percent of the slides were rehydrated . Participants who tested positive underwent a diagnostic evaluation that included colonoscopy .  Vital status was ascertained for all study participants during 13 years of follow-up . A committee determined causes of death . A single pathologist determined the stage of each tissue specimen . Differences in mortality from colorectal cancer , the primary study end point , were monitored with the sequential log-rank statistic . RESULTS The 13-year cumulative mortality per 1000 from colorectal cancer was 5.88 in the annually screened group ( 95 percent confidence interval , 4.61 to 7.15 ) , 8.33 in the biennially screened group ( 95 percent confidence interval , 6.82 to 9.84 ) , and 8.83 in the control group ( 95 percent confidence interval , 7.26 to 10.40 ) . The rate in the annually screened group , but not in the biennially screened group , was significantly lower than that in the control group . Reduced mortality in the annually screened group was accompanied by improved survival in those with colorectal cancer and a shift to detection at an earlier stage of cancer . CONCLUSIONS Annual fecal occult-blood testing with rehydration of the sample s decreased the 13-year cumulative mortality from colorectal cancer by 33 percent BACKGROUND There is growing evidence that faecal-occult-blood ( FOB ) screening may reduce colorectal cancer ( CRC ) mortality , but this reduction in CRC mortality has not been shown in an unselected population -based r and omised controlled trial . The aim of this study was to assess the effect of FOB screening on CRC mortality in such a setting . METHODS Between February , 1981 , and January , 1991 , 152,850 people aged 45 - 74 years who lived in the Nottingham area of the UK were recruited to our study . Participants were r and omly allocated FOB screening ( 76,466 ) or no screening ( controls ; 76,384 ) . Controls were not told about the study and received no intervention . Screening-group participants were sent a Haemoccult FOB test kit with instructions from their family doctor . FOB tests were not rehydrated and dietary restrictions were imposed only for retesting borderline results . Individuals with negative FOB tests at the first screening , together with those who tested positive but in whom no neoplasia was found on colonoscopy , were invited to take part in further screening every 2 years . Screening was stopped in February , 1995 , by which time screening-group participants had been offered FOB tests between three and six times . Screening-group participants who had a positive test were offered full colonoscopy . All participants were followed up until June , 1995 . The primary outcome measure was CRC mortality . FINDINGS Of the 152,850 individuals recruited to the study , 2599 could not be traced or had emigrated and were excluded from the analysis . Thus , there were 75,253 participants in the screening group and 74,998 controls . 44,838 ( 59.6 % ) screening-group participants completed at least one screening . 28,720 ( 38.2 % ) of these individuals completed all the FOB tests they were offered and 16,118 ( 21.4 % ) completed at least one screening but not all the tests they were offered . 30,415 ( 40.4 % ) did not complete any test . Of 893 cancers ( 20 % stage A ) diagnosed in  screening-group participants ( CRC incidence of 1.49 per 1000 person-years ) , 236 ( 26.4 % ) were detected by FOB screening , 249 ( 27.9 % ) presented after a negative FOB test or investigation , and 400 ( 44.8 % ) presented in non-responders . The incidence of cancer in the control group ( 856 cases , 11 % stage A ) was 1.44 per 1000 person-years . Median follow-up was 7.8 years ( range 4.5 - 14.5 ) . 360 people died from CRC in the screening group compared with 420 in the control group-a 15 % reduction in cumulative CRC mortality in the screening group ( odds ratio=0.85 [ 95 % ; CI 0.74 - 0.98 ] , p = 0.026 ) . INTERPRETATION Our findings together with evidence from other trials suggest that consideration should be given to a national programme of FOB screening to reduce CRC mortality in the general population Objective To assess long-term quality of life in a population -based sample of rectal cancer patients . Summary Background Data Quality of life in rectal cancer patients who suffer reduced bowel and sexual function is very important . Few studies , however , have long term follow-up data or sufficient sample sizes for reliable comparisons between operation groups . Patients and Methods A 4-year prospect i ve study of rectal cancer patients ’ quality of life was assessed by using the European Organization for Research and Treatment of Cancer QLQ-30 and CR38 question naires . Results A total of 329 patients returned question naires . Overall , anterior resection patients had better quality of life scores than abdominoperineal extirpation patients . High-anterior resection patients had significantly better scores than both low-anterior resection and abdominoperineal extirpation patients . Low-anterior resection patients , however , overall had a better quality of life than abdominoperineal extirpation patients , especially after 4 years . Abdominoperineal extirpation patients ’ quality of life scores did not improve over time . Stoma patients had significantly worse quality of life scores than nonstoma patients . Quality of life improved greatly for patients whose stoma was reversed . Conclusions Anterior resection and nonstoma patients , despite suffering micturition and defecation problems , had better quality of life scores than abdominoperineal extirpation and stoma patients . Comparisons between abdominoperineal extirpation and anterior resection patients should consider the effect of temporary stomas . Improvements in quality of life scores over time may be explained by reversal of temporary stomas or physiologic adaptation PURPOSE : This study was undertaken for the comparison of local resection for early rectal carcinomas using transanal endoscopic microsurgery or anterior resection . METHODS : Data from 50 of 52 patients with proven adenocarcinoma ( GI/II ) and intraluminal ultrasound with Stage uT1 N negative ( uTNM ) were evaluated in a prospect i ve r and omized study with two therapeutic arms : transanal endoscopic microsurgery ( TEM ; n=24 ) or anterior resection ( AR ; n=26 ) , performed under general anesthesia . RESULTS : Patients ' ages and rectal tumor locations showed insignificant differences of distribution in comparison of TEM with AR ( Welsh 's alternatet-test;t-test ) . Local recurrence ( 4.2 percent ) and five-year survival rates ( 96 percent ) differed insignificantly ( log-rank test ) . Early postoperative mortality was zero . Significant differences were found comparing time of hospitalization , loss of blood , operation time , and opiate analgesia ( Welsh 's alternatet-test ; Wilcoxon 's test ; eachP < 0.05 ) . Early and late morbidity differed considerably . CONCLUSIONS : Lower morbidity , similar local recurrence , and survival rates favor the TEM technique . Comparable results in survival rate to the gold st and ard ( AR ) are objective arguments for choosing the adequate surgical procedure . For early rectal cancer , the minimum invasive TEM technique should be preferred because of superior overview during operation with safer suturing after meticulous full wall thickness excision OBJECTIVES : Endoscopic submucosal dissection ( ESD ) is currently not a common treatment for colorectal neoplasms because it is time consuming and technically difficult . Flushknife — an electrosurgical endo-knife with a water-jet function — is expected to reduce the difficulty of colorectal ESD . The objective of this study was to investigate the efficacy of a water-jet function for colorectal ESD . METHODS : This study was a prospect i ve r and omized controlled trial , which was conducted at a cancer referral center . A total of 49 patients , with a total of 51 superficial colorectal neoplasms ( median tumor size of 30 mm ) , were enrolled and r and omly assigned to undergo ESD using either the Flexknife ( electrosurgical endo-knife without a water-jet function ) or the Flushknife . Tumors were resected by ESD using each endo-knife . The procedures were conducted by two endoscopists . Operation time was defined as the main outcome measure . RESULTS : En bloc resection was achieved in 23 out of 26 ( 88 % ) lesions in the Flexknife group and in 24 out of 24 ( 100 % ) lesions in the Flushknife group . The mean operation time ( 95 % confidence interval ) was 87.3 ( 71.3–103.4 ) min in the Flexknife group and 61.0 ( 49.3–72.7 ) min in the Flushknife group ( P=0.02 ) . The Flushknife reduced the number of endoscopic device changes ( P=0.001 ) , the number of submucosal injections ( P=0.001 ) , and the mean amount of injected hyaluronate sodium ( P=0.001 ) compared with the Flexknife . No severe adverse events were observed in either group . CONCLUSIONS : Without increasing adverse events , the endo-knife with a water-jet function efficiently reduced the operation time of colorectal ESD in patients with large superficial colorectal neoplasms . ( University hospital Medical Information Network Clinical Trials Registry number UMIN000001302 PURPOSE The purpose of this national study was to examine the long-term results of transanal excision compared with major surgery of T1 rectal cancer . METHODS This prospect i ve study from the Norwegian Rectal Cancer Project included all 291 patients with a T1M0 tumor within 15 cm from the anal verge treated by anterior resection , abdominoperineal resection , Hartmann ’s procedure , or transanal excision in the period from November 1993 to December 1999 . RESULTS Two hundred fifty-six patients were treated by major surgery and 35 patients by transanal excision .  None of the patients had neoadjuvant therapy . Macroscopic tumor remnants ( R2 ) occurred in 17 percent ( 6/35 ) of the transanal excisions , while major surgery obtained 100 percent R0 resections . Eleven percent of the patients treated with major surgery had gl and ular involvement . There were no significant differences according to tumor localization , size , or differentiation between Stage I and Stage III tumors . Patients treated with transanal excision were older than patients having major surgery  ( mean age , 77 vs. 68 years , P < 0.001 ) . After curative resection ( R0 , R1 , Rx ) the five-year rate of local recurrence was 12 percent ( 95 percent confidence interval , 0–24 ) in the transanal excision group compared with 6 percent ( 95 percent confidence interval , 2–10 ) after major surgery ( P = 0.010 ) . The overall five-year survival was 70 percent ( 95 percent confidence interval , 52–88 ) in the transanal excision group compared with 80 percent ( 95 percent confidence interval , 74–85 ) in the major surgery group ( P = 0.04 ) and the five-year disease-free survival was 64 percent ( 95 percent confidence interval , 46–82 ) 
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Limitations of the study were : results could not be stratified according to location in the colon or rectum ; very early tumors removed by polypectomy without surgical resection were not included in the meta- analysis ; and included studies were primarily from Asian countries and results therefore need to be verified in Western population s. CONCLUSION The absence of lymphatic invasion , budding , submucosal invasion ≥ 1 mm , and poor histological differentiation were each associated with low risk of LNM .