***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 The possible benefit for patients from follow‐up  examinations after curative surgery for colorectal cancer is unproven . The purpose of this study was to determine whether survival is improved by frequent follow‐up examinations Objective To assess whether colon cancer follow-up can be organised by general practitioners ( GPs ) without a decline in the patient 's quality of life ( QoL ) and increase in cost or time to cancer diagnoses , compared to hospital follow-up . Design R and omised controlled trial . Setting Northern Norway Health Authority Trust , 4 trusts , 11 hospitals and 88 local communities . Participants Patients surgically treated for colon cancer , hospital surgeons and community GPs . Intervention 24-month follow-up according to national guidelines at the community GP office . To ensure a high follow-up guideline adherence , a decision support tool for patients and GPs were used . Main outcome measures Primary outcomes were QoL , measured by the global health scales of the European Organisation for Research and Treatment of Cancer QoL Question naire ( EORTC QLQ C-30 ) and EuroQol-5D ( EQ-5D ) . Secondary outcomes were cost-effectiveness and time to cancer diagnoses . Results 110 patients were r and omised to intervention ( n=55 ) or control ( n=55 ) , and followed by 78 GPs ( 942 follow-up months ) and 70 surgeons ( 942 follow-up months ) , respectively . Compared to baseline , there was a significant improvement in postoperative QoL ( p=0.003 ) , but no differences between groups were revealed ( mean difference at 1 , 3 , 6 , 9 , 12 , 15 , 18 , 21 and 24-month follow-up appointments ) : Global Health ; Δ−2.23 , p=0.20 ; EQ-5D index ; Δ−0.10 , p=0.48 , EQ-5D VAS ; Δ−1.1 , p=0.44 . There were no differences in time to recurrent cancer diagnosis ( GP 35 days vs surgeon 45 days , p=0.46 ) ; 14 recurrences were detected ( GP 6 vs surgeon 8) and 7 metastases surgeries performed ( GP 3 vs surgeon 4 ) . The follow-up programme initiated 1186 healthcare contacts ( GP 678 vs surgeon 508 ) , 1105 diagnostic tests ( GP 592 vs surgeon 513 ) and 778 hospital travels ( GP 250 vs surgeon 528 ) . GP organised follow-up was associated with societal cost savings ( £ 8233 vs £ 9889 , p<0.001 ) . Conclusions GP-organised follow-up was associated with no decline in QoL , no increase in time to recurrent cancer diagnosis and cost savings . Trial registration Clinical Trials.gov identifier NCT00572143 BACKGROUND Although colonoscopy plays an important role in postoperative surveillance of patients with colorectal cancer , the optimum protocol for colonoscopic surveillance has not been established . OBJECTIVE Our purpose was to compare the efficacy of 2 different colonoscopic surveillance strategies in terms of both survival and recurrence resectability . DESIGN Prospect i ve , r and omized , controlled trial . SETTING A teaching hospital in Sun Yat-sen University . PATIENTS Three hundred twenty-six consecutive patients undergoing radical surgery for colorectal cancer . INTERVENTION In the intensive colonoscopic surveillance group ( ICS group , n = 165 ) , colonoscopy was performed at 3-month intervals for 1 year , at 6-month intervals for the next 2 years , and once a year thereafter . In the routine colonoscopic surveillance group ( RCS group , n = 161 ) , colonoscopy was performed at 6 months , 30 months , and 60 months postoperatively . MAIN OUTCOME MEASUREMENTS AND RESULTS The 5-year survival rate was 77 % in the ICS group and 73 % in the RCS group ( P > .05 ) . Postoperative colorectal cancer was detected in 13 patients ( 8.1 % ) in the ICS group and in 18 patients ( 11.4 % ) in the RCS group . In the ICS group , there were more asymptomatic postoperative colorectal cancers ( P = .04 ) , more patients had reoperation with curative intent ( P = .048 ) , and the probability of survival after postoperative colorectal cancer was higher ( P = .03 ) . LIMITATION Lack of detailed characterization of metachronous colorectal adenomas in these patients . CONCLUSIONS Although the patients in the ICS group had more curative operations for postoperative colorectal cancer and survived significantly longer , ICS itself did not improve overall survival OBJECTIVE To determine whether an intensified follow-up of patients with colorectal cancer can lead to improved reresectability and a better long-term survival . DESIGN A prospect i ve r and omized trial of 106 patients . SETTING Oulu University Hospital , a referral center in northern Finl and . PATIENTS A total of 106 consecutive patients who underwent radical resection for colorectal cancer , 54 of whom were r and omized into a conventional follow-up group and 52 into an intensified follow-up group .  MAIN OUTCOME MEASURES After a 5-year follow-up , the time of detection of recurrence , the recurrence rates , the first method showing recurrence , the mode of recurrence , reresectability , and survival were compared between the groups . RESULTS The recurrences were identified earlier in the intensified follow-up group than in the conventional follow-up group ( mean + /- SD , 10 + /- 5 months vs 15 + /- 10 months ) . The overall recurrence rate was 41 % , with 39 % in the conventional group and 42 % in the intensified group . Carcinoembryonic antigen determination was the most common method showing recurrence in both groups . Endoscopy and ultrasound were beneficial in the intensified follow-up group , but computed tomography failed to improve the diagnostics . The mode of recurrence did not differ between the groups . Radical resections were performed on 19 % ( 8/43 ) of the patients , 14 % ( 3/21 ) in the conventional group and 22 % ( 5/22 ) in the intensified group . The cumulative 5-year survival was 54 % in the conventional group and 59 % in the intensified group . CONCLUSION Earlier detection of recurrent colorectal cancer by intensified follow-up does not lead to either significantly increased reresectability or improved 5-year survival Introduction The COLOFOL trial , a prospect i ve r and omized multicenter trial comparing two follow-up regimes after curative surgical treatment for colorectal cancer , focuses on detection of asymptomatic recurrences . This paper aims to describe the design and recruitment procedure in the COLOFOL trial , comparing demographic characteristics between r and omized patients and eligible patients not included in the study . Material s and methods COLOFOL was design ed as a pragmatic trial with wide inclusion criteria and few exclusion criteria , in order to obtain a sample reflecting the general patient population . To be eligible , patients had to be 75 years or younger and curatively resected for stage II or III colorectal cancer . Exclusion criteria were hereditary colorectal cancer , no signed consent , other malignancy , and life expectancy less than 2 years due to concomitant disease . In four of the 24 participating centers , we scrutinized hospital inpatient data  to identify all colorectal cancer patients who underwent surgery  , in order to ascertain all eligible patients who were not included in the study and to compare them with enrolled patients . Results Of a total of 4,445 eligible patients , 2,509 patients were r and omized ( 56.4 % inclusion rate ) . A total of 1,221 eligible patients were identified in the scrutinized hospitals , of which 684 ( 56 % ) were r and omized . No difference in age or sex distribution was observed between r and omized and nonr and omized eligible patients . However , a difference was noted in tumor location and stage distribution , with 5.6 % more patients in the r and omized group having colon cancer and 6.7 % more patients having stage II disease . Conclusion Patients in the two study arms were not only demographically similar , but also similar to nonincluded eligible patients , apart from stage and localization . The analyses will be stratified by these variables . Taken together , we conclude that our trial results will be robust and possible to extrapolate to the target population IMPORTANCE Intensive follow-up after surgery for colorectal cancer is common practice but is based on limited evidence . OBJECTIVE To assess the effect of scheduled blood measurement of carcinoembryonic antigen ( CEA ) and computed tomography ( CT ) as follow-up to detect recurrent colorectal cancer treatable with curative intent . DESIGN , SETTING , AND PARTICIPANTS R and omized clinical trial in 39 National Health Service hospitals in the United Kingdom ; 1202 eligible participants were recruited between January 2003 and August 2009 who had undergone curative surgery for primary colorectal cancer , including adjuvant treatment if indicated , with no evidence of residual disease on investigation . INTERVENTIONS Participants were r and omly assigned to 1 of 4 groups : CEA only ( n = 300 ) , CT only ( n = 299 ) , CEA+CT ( n = 302 ) , or minimum follow-up ( n = 301 ) .  Blood CEA  was measured every 3 months for 2 years , then every 6 months for 3 years ; CT scans of the chest , abdomen , and pelvis were performed every 6 months for 2 years , then annually for 3 years ; and the minimum follow-up group received follow-up if symptoms occurred . MAIN OUTCOMES AND MEASURES The primary outcome was surgical treatment of recurrence with curative intent ; secondary outcomes were mortality ( total and colorectal cancer ) , time to detection of recurrence , and survival after treatment of recurrence with curative intent . RESULTS After a mean 4.4 ( SD , 0.8 ) years of observation , cancer recurrence was detected in 199 participants ( 16.6 % ; 95 % CI , 14.5%-18.7 % ) overall ; 71 of 1202 participants ( 5.9 % ; 95 % CI , 4.6%-7.2 % ) were treated for recurrence with curative intent , with little difference according to Dukes staging ( stage A , 5.1 % [ 13/254 ] ; stage B , 6.1 % [ 34/553 ] ; stage C , 6.2 % [ 22/354 ] ) . Surgical treatment of recurrence with curative intent was 2.3 % ( 7/301 ) in the minimum follow-up group , 6.7 % ( 20/300 ) in the CEA group , 8 % ( 24/299 ) in the CT group , and 6.6 % ( 20/302 ) in the CEA+CT group . Compared with minimum follow-up , the absolute difference in the percentage of patients treated with curative intent in the CEA group was 4.4 % ( 95 % CI , 1.0%-7.9 % ; adjusted odds ratio [ OR ] , 3.00 ; 95 % CI , 1.23 - 7.33 ) , in the CT group was 5.7 % ( 95 % CI , 2.2%-9.5 % ; adjusted OR , 3.63 ; 95 % CI , 1.51 - 8.69 ) , and in the CEA+CT group was 4.3 % ( 95 % CI , 1.0%-7.9 % ; adjusted OR , 3.10 ; 95 % CI , 1.10 - 8.71 ) . The number of deaths was not significantly different in the combined intensive monitoring groups ( CEA , CT , and CEA+CT ; 18.2 % [ 164/901 ] ) vs the minimum follow-up group ( 15.9 % [ 48/301 ] ; difference , 2.3 % ; 95 % CI , -2.6 % to 7.1 % ) . CONCLUSIONS AND RELEVANCE Among patients who had undergone curative surgery for primary colorectal cancer , intensive imaging or CEA screening each provided an increased rate of surgical treatment of recurrence with curative intent compared with minimal follow-up ; there was no advantage in combining CEA and CT . If there is a survival advantage to any strategy , it is likely to be small . TRIAL REGISTRATION is rct n.org Identifier : 41458548 Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more PURPOSE Although systematic postoperative surveillance of patients with colorectal cancer has been demonstrated to improve survival , it remains unknown whether a more intensive strategy provides any significant advantage . This prospect i ve , multicenter , r and omized , controlled trial was aim ed at comparing the efficacy of two different surveillance strategies in terms of both survival and recurrence resectability . PATIENTS AND METHODS Patients with stage II or III colorectal cancer were allocated r and omly to either a simple surveillance strategy including clinical evaluation and serum carcinoembryonic antigen monitoring , or an intensive strategy in which abdominal computed tomography or ultrasonography , chest radiograph , and colonoscopy were added . RESULTS A total 
    Output:
    
Based on pooled data from r and omized trials published from 1995 to 2016 , the anticipated survival benefit from surgical treatment result ing from earlier detection of metastases has not been achieved