***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 Treatment of rectal cancer with neoadjuvant radiotherapy has been shown to reduce local recurrence and improve overall survival . The role of chemoradiotherapy in patients with T2 , N0 and early T3 , N0 rectal cancer , treated by radical surgery with total mesorectal excision  , remains controversial . The aim of this study was to identify predictors of recurrence in this group of patients to enhance treatment selection . PATIENTS AND METHODS One hundred patients with primary T2 - 3 , N0 adenocarcinoma of the rectum , uniformly treated by surgery alone , were studied . The pathology slides available for 97 patients were re review ed . Three patients with incomplete data sets were excluded . Clinical and survival data were obtained from a prospect i ve computerized data base and up date d from hospital and office charts . The study end points were disease-free survival , disease-specific survival ( DSS ) , time to pelvic recurrence ( PR ) , and distant recurrence . RESULTS Complete follow-up was available for all study patients . Median follow-up was 79.5 months ( range , 57.7 to 105.9 months ) . During this time period 30 patients ( 31.9 % ) died as a result of disease and 64 patients ( 68.1 % ) remained alive and disease free . Five-year DSS was 73 % . The cumulative risk for PR was 8 % at 5 years and 10 % at 8 years . Lymphovascular invasion , preoperative serum carcinoembryonic antigen ( CEA > 5 ng/mL ) level , and age older than 70 years were all associated with adverse outcome . CONCLUSION Patients with T2 - 3 , N0 rectal cancers and either lymphovascular invasion or elevated CEA levels have reduced survival and a higher incidence of PR , and should be considered for future r and omized trials Purpose Carcinoembryonic antigen ( CEA ) measurements performed preoperatively and during the early postoperative period were examined prospect ively to assess their prognostic value for colorectal cancer ( CRC ) patients receiving curative surgery . Methods Between 2000 and 2004 , 1,361 patients with CRC who underwent curative surgery at the Taipei Veterans General Hospital were enrolled prospect ively .  CEA  was measured prior to surgery and during the third or fourth postoperative week . The endpoint was length of postoperative disease-free survival , and prognostic importance was determined using the log-rank test and Cox regression hazard model . Results Six hundred ( 44.1 % ) CRC patients had high CEA concentrations preoperatively , and 188 ( 13.8 % ) patients retained high values postoperatively . Within the median follow-up period of 61 ( 6–108 ) months , CRC recurred in 313 patients . By univariate analysis TNM staging , tumor differentiation , lymphovascular invasion , preoperative CEA concentration , and postoperative CEA concentration affected the outcome . By multivariate analysis , the prognostic importance of postoperative CEA was retained ( 95 % CI , 1.73–3.01 ; HR = 2.28 ) but that of preoperative CEA was lost ( 95 % CI , 0.82–1.33 ; HR = 1.05 ) . CRC recurred earlier in patients with high postoperative CEA concentrations ; metastasis to the liver was common ( 72.3 % ) among patients in this group . Conclusions Early postoperative CEA concentration is an independent prognostic factor for CRC . Patients with high postoperative CEA values  should receive aggressive follow-up examinations for early relapse of CRC , with special attention paid to recurrence at the liver 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 BACKGROUND In curable colorectal cancer ( CRC ) , preoperative serum carcinoembryonic antigen ( CEA ) ( preCEA ) has been reported to have predictive prognostic value . However , data remains insufficient to support its clinical use . The aim of the current study was to vali date the prognostic impact of preCEA in Dukes ' C CRC . PATIENTS AND METHODS The prognostic significance of preCEA for 237 Dukes ' C CRC patients assessed retrospectively ( between 1990 and 2000 : previous cases ) and the prospect i ve relevance for 197 counterparts ( between 2001 and 2004 : recent cases ) according to preCEA , were both examined . RESULTS The previous cases showed the most potent impact of preCEA as an independent prognostic factor ( hazard ratio=2.0 , p=0.003 ) among the clinicopathological factors using a multivariate proportional hazard model , while the recent cases did not even show a univariate prognostic impact . A significant difference in the prognosis between the two periods was only found in the patients with elevated  preCEA  administered adjuvant chemotherapy ( ADT ) ( p=0.03 ) . Between the two terms , a dramatic change of ADT regimens from 5FU alone ( p<0.001 ) to 5FU in combination with leucovorin ( p<0.001 ) and /or irinotecan ( p-0.0009/0.005 ) was introduced , and N2 patient survival was dramatically improved . However , a significant prognostic difference for the elevated preCEA patients with ADT could not be demonstrated by sub- analysis of N1 and N2 disease due to diminished correlation of preCEA and the N factor ( p=0.02 to 0.5 ) , indicating that preCEA did not predict chemosensitivity . CONCLUSION The preCEA is no longer useful in predicting prognosis with Dukes ' C CRC patients , because of the loss of preCEA association with the N factor , putatively through undefined diagnostic or therapeutic advancement Abstract Objective . The combination of plasma tissue inhibitor of metalloproteinases-1 ( TIMP-1 ) and carcinoembryonic antigen ( CEA ) may be valuable biomarkers for early detection of colorectal cancer ( CRC ) . A prospect i ve , population based study was performed to vali date this hypothesis . Material and methods . Individuals ( n = 4509 ) referred for large bowel endoscopy due to symptoms of CRC were prospect ively included . Baseline data and concurrent diseases were recorded . The primary endpoint was detection of CRC and findings at examinations were recorded using International Classification of Diseases-10 codes . Plasma was obtained before endoscopy and  TIMP-1 and CEA levels were determined after the inclusion of all individuals . Results . Findings were based on sigmoidoscopy in 1766 and colonoscopy  in 2743 individuals .  Colon cancer ( CC ) was detected in 184 and rectal cancer in 110 individuals . Ten individuals with other cancers , 856 with adenomas and 1176 with non-neoplastic findings were also detected . The biomarker levels were increased in a variety of diseases including CRC compared to individuals without any findings at endoscopy . A multivariable analysis demonstrated that both markers were significant and independent detectors of CRC . Combining both biomarkers , independent contributions from each ( TIMP-1 , odds ratio ( OR ) = 1.8 ( 95 % confidence interval ( CI ) : 1.4–2.2 ) , p < 0.0001 ; CEA < 5 ng/ml , OR = 1.6 , 1.3–1.9 , or ≥5 ng/ml , OR = 2.3 , 95 % CI : 1.9–2.7 ( p < 0.0001 ) ) were obtained . Subgroup analysis of individuals examined by colonoscopy with CC as the endpoint showed that combining both biomarkers , independent contributions from each ( TIMP-1 , OR = 2.5 , 95 % CI : 1.8–3.4 , p < 0.0001 ; CEA < 5 ng/ml , OR = 1.4 , 95 % CI : 1.1–1.8 , and CEA ≥ 5 ng/ml , OR = 2.3 , 95 % CI : 1.8–3.0 ( p < 0.0001 ) ) were obtained . Conclusions . This prospect i ve validation study supports the use of the combination of plasma TIMP-1 and CEA protein measurements as a potential aid in early detection of CRC and specifically of CC Purpose We determined the prognostic value of carcinoembryonic antigen ( CEA ) clearance after tumor resection with serial evaluation of postoperative CEA levels in rectal cancer . Methods Between 1994 and 2004 , we retrospectively review ed 122 patients with rectal cancer whose serum CEA levels were measured on the preoperative day and postoperative days 7 and 30 . Patients with preoperative CEA levels < 5.0 ng/ml were excluded . An exponential trend line was drawn using the three CEA values . Patients were categorized into three groups based on R2 values calculated through trend line , which indicates the correlation coefficient between exponential graph and measured CEA values : exponential decrease group ( group 1 : 0.9 < R2 ≤ 1.0 ) , nearly exponential decrease group ( group 2 : 0.5 < R2 ≤ 0.9 ) , and r and omized clearance group ( group 3 : 0.5 ≤ R2 ) . We then analyzed the CEA clearance pattern as a prognostic indicator . Results With a median follow-up of 57 months , the 5-year overall survival was 62.3 % vs. 48.1 % vs. 25 % and the 5-year disease-free survival was 58.6 % vs. 52.7 % vs. 25 % among groups 1 , 2 , and 3 ( P = 0.014 , P = 0.027 , respectively ) in patients with stage III rectal cancer . For those with stage II rectal cancer , the 5-year overall survival rate of group 1 was significantly better than groups 2 and 3 ( 88.8 % vs. 74.1 % , respectively , P = 0.021 ) . Conclusions The postoperative pattern of CEA clearance is a useful prognostic determinant in patients with rectal cancer . Patients with a r and omized pattern of CEA clearance after tumor resection should be regarded as having the possibility of a persistent CEA source and may require consideration of intensive follow-up or adjuvant therapy 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 
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Analysis of these papers found higher preoperative CEA levels were associated with advanced or metastatic disease and thus poorer prognosis .
Postoperatively , failure of CEA to return to normal was found to be indicative of residual or recurrent disease .
However , measurement of CEA levels alone was not sufficient to improve survival rates .