Recurrence and malignancy rates in a benign colorectal neoplasm patient cohort: results of a 5-year analysis in a managed care environment

OBJECTIVE: To estimate the apparent recurrence rates of benign neoplasms and the development of malignant colorectal neoplasms over a 5-yr period in a high risk managed care population. METHODS: Using the CPT and ICD-9 CM codes, a cohort of subjects with benign neoplasms were identified with a colonoscopy in 1992 from a longitudinal claims database (MarketScan). Three groups of subjects (benign neoplasms with polypectomy, benign neoplasms without polypectomy, and no neoplasms) were evaluated. Five-year recurrence rates of benign or new malignant colorectal neoplasms were determined for the baseline benign neoplasms with polypectomy and no neoplasm groups. For the benign neoplasm without polypectomy, only rates for malignancy were evaluated. RESULTS: Of 16,293 subjects at baseline, 39.50% were diagnosed with benign and 5.50% with malignant neoplasms. The 5-yr cumulative incidence of benign neoplasms in subjects without an index neoplasm (n = 8,967) was 7.92% compared to the recurrence of 40.93% in subjects with a benign neoplasm and polypectomy (n = 4,046) at baseline (p < 0.001). The 5-yr cumulative incidence rates of malignant colorectal neoplasms in the no neoplasm (n = 8,967) and benign neoplasm groups (n = 6,438) were 1.81% and 2.55%, respectively (p < 0.005). A lower 5-yr malignancy rate was observed in benign neoplasm group with polypectomy (2.17%) compared to the benign neoplasm group without polypectomy (3.18%) (p < 0.05). CONCLUSION: The high recurrence rate of benign colorectal neoplasms and a higher incidence of colorectal cancer in subjects at high risk (history of benign colorectal neoplasm) highlight a healthcare opportunity for surveillance and/or interventions to reduce the morbidity associated with colorectal neoplasms.     

ASSESSMENT OF MISS AND INCIDENCE RATES OF NEOPLASTIC POLYPS AT COLONOSCOPY

Background: The incidence rate after a colonoscopic polypectomy includes the true incidence rate of new polyp formation and miss rate of polyps at the initial colonoscopy. It is therefore important to assess accurate incidence rates of polyps as well as those of missing polyps with colocoscopy. Methods: Six hundred and eighty‐eight patients who underwent total colonoscopy twice within 30 days were investigated to determine the miss rates of neoplastic polyps under colonoscopy. The cumulative incidence rates of neoplasm were evaluated by the Kaplan‐Meier method in another series of investigations on 864 patients who underwent surveillance total colonoscopy over 31 days. Results: In 157 (22.8%) patients out of 688, 200 neoplastic lesions (all adenomas) were missed during the first examination. The miss rate was 16% for adenomas ≤ 5 mm and 2% for adenomas > 10 mm. The miss rates of patients with 0, 1, 2, or > 2 neoplastic polyps on the first examination was 5.3%, 19.6%, 23.5% and 35.5%, respectively. One year cumulative incidence rates of patients with 1, 2, or > 2 neoplastic polyps on the first examination were 18.4%, 21.1% and 34.2%, respectively. Conclusion: Detection of multiple neoplasms on index colonoscopy predicts a high miss rate and cumulative incidence rate on surveillance colonoscopy. A substantial proportion of neoplasms detected at nearly 1‐year postpolypectomy surveillance colonoscopy were missed at the initial total colonoscopy.     

Right-side shift of metachronous colorectal adenomas after polypectomy

OBJECTIVE: In our previous study, we showed that the development of adenomas in the right-side colon increased with aging in subjects with no colorectal neoplasms. The aim of the present study was to investigate the location of metachronous colorectal adenomas after endoscopic polypectomy. MATERIAL AND METHODS: The records of a colonoscopic follow-up study on 2900 subjects after polypectomy were analyzed. The location was classified as the right-side colon and left-side colon at the splenic flexure. Subjects were classified into three groups according to distribution of adenomas at the initial two colonoscopies: those with adenomas located only in the left side (LL), adenomas in both the left side and right side (LR), and adenomas only in the right side (RR). Distribution of initial and metachronous adenomas was evaluated according to age. RESULTS: The annual incidence rates of colorectal adenomas in the left-side colon were estimated to be 8.56%, 11.2%, and 5.71% in the LL, LR, and RR groups, respectively. The rates in the right side were 5.91%, 15.5%, and 9.38%, respectively. The incidence rates in the left side in the age groups <40, 40-49, 50-59, and > or =60 years were 6.93%, 8.08%, 8.33%, and 8.48%/year, respectively. Those in the right side were 4.91%, 7.27%, 9.86%, and 12.41%/year, respectively. CONCLUSIONS: Although there may be individual predilection for right-side or left-side location of colorectal adenomas, aging tends to increase the number of adenomas in the right-side colon, while only modestly affecting those in the left-side colon.     

A prospective, partly randomized study of the effectiveness of repeated examination of the colon after polypectomy and radical surgery for cancer

Results of 629 colonoscopies and 130 double-contrast examinations, performed during the first 2 years of a prospective, partly randomized cancer prophylactic programme, are reported. The patients were not more than 75 years old and had no previous diagnosis of adenoma or cancer. Repeated colonoscopy 3 months after polypectomy in 80 patients increased the chance of obtaining a complete colonoscopy from 70% to 86%, and the hepatic flexure was reached in a further 9%. Thirteen had polypectomy during the second colonoscopy. The gain in number of patients with adenomas was highest in those with sessile villous adenomas, carcinoma in situ, and mucosal carcinoma. Repeated colorectal examinations every 6 months in these resulted in recurrence rates of 13 of 33, 3 of 23, and 2 of 15 (18 months), respectively. The same figures for patients with stalked polyps, allocated to examination every 6 months, were 3 of 34, 1 of 21, and 2 of 14. Colonoscopy was also performed within 3 months of radical surgery for colorectal cancer, and 35 of 142 patients had polypectomy. Repeated examinations every 6 months resulted in recurrence rates for adenomas of 11 of 85, 3 of 46, and 1 of 34. One new cancer after 12 months could be treated radically. Five uncomplicated laparotomies were performed after the 629 colonoscopies because of perforation or bleeding.     

How often should we perform surveillance colonoscopy after surgery for colorectal cancer?

Purpose

Surveillance colonoscopy is undertaken after resection of colorectal cancer to detect and treat local recurrence and metachronous lesions, with the aim of improving survival. This study aimed to clarify the current timing of surveillance colonoscopies and evaluate the rates of local recurrence and metachronous tumors.

Methods

We retrospectively analyzed data from 459 patients who underwent surveillance colonoscopy at our institution after curative resection of colorectal cancer. The number and timing of surveillance colonoscopies, incidence of local recurrence and metachronous lesions, pathological findings of lesions, treatment of lesions, and outcomes were recorded.

Results

The first surveillance colonoscopy was undertaken at 6–18 months after surgery in 73 % of patients. Local recurrence was detected in three cases (0.7 %), all during the first surveillance colonoscopy, which was performed >1 year after surgery. These three patients all underwent additional surgery and were alive 5 years later. Invasive metachronous cancers were detected in six patients (1.3 %) at 18–57 months after surgery, and advanced adenomas were detected in 30 patients.

Conclusion

Considering the low incidence of postoperative lesions and the timing of lesion detection, reducing the number of surveillance colonoscopies after surgery for colorectal cancer may be appropriate.     

Colorectal neoplasm in asymptomatic Asians: a prospective multinational multicenter colonoscopy survey

BACKGROUND: Colorectal neoplasm is rapidly increasing in Asia, but a guideline for screening is not available. OBJECTIVE: To evaluate the characteristics of colorectal neoplasm in asymptomatic Asian subjects. DESIGN: Prospective cohort study. SETTING: Multinational multicenters, including both primary and referral centers in Asia. PATIENTS: A total of 860 consecutive asymptomatic adults undergoing screening colonoscopy in 11 Asian cities from July 2004 to December 2004. Patients under 16 years old; those patients with a colorectal resection history, colonoscopies, or barium enema within 5 years; symptoms suggestive of colorectal diseases; and those who had undergone surveillance colonoscopy were excluded. MAIN OUTCOME MEASUREMENTS: The incidence and distribution of colorectal neoplasm and advanced neoplasm. RESULTS: The mean age (+/-SD) was 54.4+/-11.6 years; 471 were men (54.8%). The prevalence of colorectal neoplasm and advanced neoplasm was 18.5% and 4.5%, respectively. Male sex, advancing age, and a family history of colorectal cancer were risk factors for advanced neoplasm. Of the 168 patients with colorectal neoplasm, 76 had distal neoplasm only (45.2%), 66 had proximal neoplasm only (39.3%), and 26 had both proximal and distal neoplasms (15.5%). Although the presence of distal advanced neoplasm was a significant risk factor for proximal advanced neoplasm, 14 of the 758 subjects without distal neoplasm had proximal advanced neoplasm (1.8%). LIMITATIONS: The small number of enrolled subjects, especially from certain ethnic groups. CONCLUSIONS: The overall prevalence of advanced colorectal neoplasm in asymptomatic Asians is comparable with the West. Male sex, advancing age, and a family history of colorectal cancer were associated with a higher risk of advanced neoplasm.     

Number of aberrant crypt foci in the rectum is a useful surrogate marker of colorectal adenoma recurrence

Aim: Endoscopic screening and removal of colorectal adenomas can reduce the incidence of colorectal cancer. However, given the possibility of adenoma recurrence, surveillance colonoscopy is currently recommended after the initial screening and removal of colorectal adenomas. Aberrant crypt foci (ACF) have been shown to serve as a reliable surrogate marker of colorectal carcinogenesis. In this study, the relationship between the number of ACF at the initial endoscopic polypectomy and the likelihood of colorectal adenoma recurrence after polypectomy were investigated. Methods: High‐magnification chromoscopic colonoscopy was performed in 82 subjects who underwent endoscopic polypectomy to identify ACF in the lower rectum. Surveillance colonoscopy was then performed 3 years after the baseline polypectomy at Yokohama City University Hospital. Results: The number of ACF was greater in patients who showed adenoma recurrence (7.88 ± 6.35) than in those who did not (2.19 ± 2.95) (P < 0.001). Receiver–operating curve analysis showed that the number of ACF was a highly specific predictor of the risk of adenoma recurrence. Conclusions: This is the first study conducted to investigate the relationship between the number of ACF after endoscopic polypectomy and the likelihood of recurrence of colorectal adenomas. These results suggest that the number of ACF is a useful predictor of the likelihood of colorectal adenoma recurrence.     

Right-side shift of colorectal adenomas with aging

BACKGROUND: Although it is known that right-side colon cancers increase with aging, the location of adenomas according to age has been controversial. Adenomas found at initial colonoscopies may be a mixture of polyps that arose at various earlier ages. OBJECTIVES: To elucidate the relationship between location and age at which adenomas actually developed. DESIGN: Prospective cohort study. SETTING: A large-scale health appraisal institution in Japan. PATIENTS: A total of 23,444 consecutive, asymptomatic Japanese who underwent total colonoscopy at their annual medical health check-up. INTERVENTIONS: We analyzed newly developed adenomas after confirmation of the absence of colorectal neoplasms by two serial total colonoscopies. MAIN OUTCOME MEASUREMENTS: The results of follow-up colonoscopies in 6304 subjects with no colorectal neoplasms at 2 initial colonoscopies were analyzed. The locations were separated into right-side colon and left-side colon from the splenic flexure. The locations of new adenomas found for the first time during the follow-up term were analyzed. RESULTS: A total of 1472 subjects developed new colorectal adenomas. In 1255 cases with single adenomas, the ratios of number of cases with right-side lesions to that with left-side lesions at the ages of <40 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, and > or =70 years were 1.18, 1.00, 1.29, 1.31, and 1.89, respectively. In 217 cases with multiple adenomas found concurrently, the percentage of cases with adenomas only on the right side at the ages of <40 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, and > or =70 years were 0%, 25%, 34%, 37%, and 63%, respectively. LIMITATIONS: Small lesions might have been missed even by 2 serial colonoscopies. CONCLUSIONS: Adenomas on the right-side colon increased with aging.     

Adenoma incidence decreases under the effect of polypectomy

AIM:To investigate whether,under the influence of pol-ypectomy,the incidence of adenoma decreases with age.METHODS:Consecutive patients with colonic adenomas identified at index colonoscopy were retrospectively selected if they had undergone three or more complete colonoscopies,at least 24 mo apart.Patients who had any first-degree relative with colorectal cancer were excluded.Data regarding number of adenomas at each colonoscopy,their location,size and histological classification were recorded.The monthly incidence density of adenomas after the index examination was estimated for the study population,by using the person-years method.Baseline adenomas were excluded from incidence calculations but their characteristics were correlated with recurrence at follow-up,using the χ 2 test.RESULTS:One hundred and fifty-six patients were included(109 male,mean age at index colonoscopy 56.8 ± 10.3 years),with follow-up that ranged from 48 to 232 mo.No significant correlations were observed between the number,the presence of villous component,or the size of adenomas at index colonoscopy and the presence of adenomas at subsequent colonoscopies(P = 0.49,0.12 and 0.78,respectively).The incidence of colonic adenomas was observed to decay from 1.4% person-months at the beginning of the study to values close to 0%,at 12 years after index colonoscopy.CONCLUSION:Our results suggest the sporadic formation of adenomas occurs within a discrete period and that,when these adenomas are removed,all neoplasia-prone clones may be extinguished.     

Incidence and recurrence rates of colorectal adenomas in first-degree asymptomatic relatives of patients with colon cancer

OBJECTIVES: Subjects with one first-degree relative affected with colorectal cancer are considered to be at increased risk of colorectal adenomas. We compared the recurrence and incidence rates of colorectal adenomas among subjects with one first-degree relative with colorectal cancer and those without family history. METHODS: A series of consecutive asymptomatic subjects successfully underwent a colonoscopy, were found to have either normal results or at least one adenoma, provided a detailed family history, and were offered a second colonoscopy 3 yr later; 190 out of 436 subjects accepted, 134/172 with one or more adenomas and 56/264 with no abnormalities at the initial examination. A first-degree family history was reported by 43/134 and 26/56, respectively. RESULTS: By multivariate analysis, the presence of adenomas at follow-up examination was significantly associated with a positive family history of colorectal cancer in both subgroups, those with a previously resected adenoma (odds ratio = 2.23, 95% CI = 1.04-4.79) and those without (odds ratio = 8.95, CI = 1.29-62.22). CONCLUSION: A history of one first-degree relative with colorectal cancer is associated with a significant increase in 3-yr cumulative incidence and recurrence rates of adenomas.     

Follow-up of a cohort of 2604 colorectal adenomas treated in 1991 and 1992. Search for parameters related to adenomatous recurrence

AIM: To evaluate the recurrence of colorectal neoplasia after endoscopic resection of adenomas. METHODS: The establishment of a register of colorectal cancers and pre-cancerous lesions for Loire-Atlantique (a French administrative division) led to the recording of files for all subjects with colorectal adenomas. The files for the cohort followed up for the years 1991 and 1992 were re-examined at the end of 1998 to determine the risk factors for recurrence. Data from control colonoscopies were recorded. RESULTS: The files of 2 208 (84.9%) of the 2 604 subjects included in the study were examined in 1998. One thousand and four hundred fifty- two subjects had at least one control colonoscopy after a mean period of 28 months: 743 (28.5%) had colorectal neoplasia recurrence, including 18 with a cancer and 50 (2%) with high-grade dysplasia adenomas. The parameters related to recurrence risk were: polyp size, number and topographic distribution of adenomas, pedunculated type, histopathological classification, especially the degree of dysplasia. CONCLUSION: Recurrence of neoplasic lesions (cancer, high grade dysplasia adenomas) may be observed after adenoma resection.     

Distal colonic neoplasms predict proximal neoplasia in average-risk, asymptomatic subjects

Flexible sigmoidoscopy has been recommended as a screening method to reduce the incidence of colorectal cancer in asymptomatic, average-risk subjects through the early detection and removal of polyps. However, the association between distal and proximal colonic neoplasia and, hence, the requirement for colonoscopic follow up of screen-detected distal neoplasms is unclear. Our aims were: (i) to evaluate the risk of having proximal neoplasms in those with distal colonic neoplasms; and (ii) to determine whether the risk was dependent on the number, size, histology or morphology of the distal lesions. We prospectively evaluated asymptomatic subjects in a flexible sigmoidoscopy based screening programme. Those with rectosigmoid neoplasia underwent colonoscopy. The number, size, histology and morphology of the polyps were recorded. Advanced lesions were defined as adenomas > 1 cm or with a villous component or severe dysplasia, carcinoma in situ or cancer. Adenomatous polyps were found in 17% (135) of screening flexible sigmoidoscopies. At colonoscopy, up to 30% of subjects with distal colonic neoplasms had synchronous proximal lesions at colonoscopy and up to 20% had advanced proximal lesions. The risk of proximal colonic neoplasia was increased in those with distal sessile colonic neoplasms but appeared independent of distal lesion size, number or morphology. In conclusion, distal colonic neoplasia predicts proximal neoplasia in up to 30% of subjects and these were advanced lesions in up to 20%. We recommend that all subjects with biopsy proven distal colonic neoplasia undergo colonoscopy.     

Colonoscopy surveillance after polypectomy

The goal of surveillance examinations after polypectomy is to detect new adenomas and missed synchronous adenomas, as well as preventing adenomas from becoming invasive or cancerous. The first colonoscopy surveillance program reported was the National Polyp Study from the United States in 1997, with an update in 2003. First screening colonoscopy and polypectomy have been shown to produce the greatest effects in reducing the incidence of colorectal cancer in patients with adenomatous polyps. However, a large number of adenomas are being discovered as a result of the increased use of colorectal cancer screening, particularly with the dramatic increase in screening colonoscopy and surveillance. Increased efficiency of surveillance colonoscopy practices is therefore needed to decrease the cost, risk, and overuse of medical resources. In developing surveillance programs, studying miss rates and incidences and performing separate evaluations are important, along with accurately assessing incidence. This is because the recurrence rate or apparent incidence after colonoscopic polypectomy includes the true incidence of new polyp formation plus the incidence of missed polyps from the initial colonoscopy. Many studies have indicated the number of adenomas on initial examination as the most significant predictor for missed adenoma and incidence of adenoma on surveillance colonoscopy. In Japan, many facets of colonoscopic examination differ from those in Western countries. Further studies are recommended to establish an appropriate and original Japanese colonoscopy surveillance program for use after polypectomy, based on guidelines from the United States.     

Retrospective analysis of missed advanced adenomas on surveillance colonoscopy

OBJECTIVE: Miss rates of large polyp/cancer during colonoscopy are reported from tertiary centers where experts do the colonoscopies. This information is important for determining surveillance intervals for repeat colonoscopy, patient safety, and malpractice issues. We evaluated retrospectively the miss rates of advanced adenomas in the setting of a GI fellowship training where most colonoscopies are done by closely supervised fellows. METHODS: We reviewed the 235 patients who had at least one repeat colonoscopy after initial polypectomy, between 1992 and 1999, at the Dayton Veterans Affairs Medical Center. Advanced adenomas were defined as polyps 10 mm or greater in size with or without a villous component or high-grade dysplasia. Data of missed advanced adenomas on 122 patients who had complete colonoscopy with satisfactory preparation and the excluded patients are reported. RESULTS: Four advanced adenomas (one had intramucosal cancer) on second colonoscopy and two advanced adenomas on third colonoscopy were missed. The miss rate of advanced adenoma for 232 patients was 1.7%, and the miss rate for the 122 patients with complete colonoscopy and satisfactory colon preparation was 2.5% and 3.3% on second and third repeat colonoscopy, respectively. No cancer was missed. CONCLUSIONS: The present study shows an advanced polyp miss rate that is comparable with other studies even in a fellowship training setting. Prospective studies with tandem surveillance colonoscopy are needed to confirm our findings.     

Frequency of advanced neoplasia in the proximal colon without an index polyp in the rectosigmoid

PURPOSE: Screening endoscopy has the potential to reduce colorectal cancer mortality. However, the efficacy of screening flexible sigmoidoscopy compared with colonoscopy strongly depends on the frequency of advanced proximal neoplasms without an index polyp in the rectosigmoid. We have therefore determined this frequency in our endoscopy population. METHODS: Endoscopic and histologic data were analyzed from all patients on whom integral colonoscopy was performed between 1980 and 1995. Advanced neoplasia was defined as cancer or adenomas >10 mm in diameter, adenomas with a villous component, or severe dysplasia. Patients with polyposis syndrome or inflammatory bowel disease were excluded. RESULTS: Colonoscopy was performed on 11,760 patients. 2,272 (19.3 percent) had at least one colorectal neoplasm, of which 39 percent had the neoplasm above the rectosigmoid. Twenty-two percent of all patients with neoplasia had no index polyp in the rectosigmoid and 16 percent of these had no index polyp, but at least one advanced proximal neoplasm. CONCLUSIONS: Although 39 percent of patients had neoplasms above the rectosigmoid, only 16 percent had an advanced proximal neoplasm without an index polyp in the rectosigmoid. This gives a figure on which to base the evaluation of screening sigmoidoscopy programs against those of screening colonoscopy.     

Colorectal cancer screening: Results of a 5-year program in asymptomatic subjects at increased risk

BACKGROUND AND AIMS: The province of Ferrara has one of the highest incidences of colorectal cancer (CRC) in Italy. In January 2000, we set up a colonoscopy screening program focussing on first-degree relatives of CRC patients. We now report the results 5 years after the beginning of the project. SCREENEES AND METHODS: In October 1999, we started a campaign stressing the usefulness of colonoscopy for the first-degree relatives of CRC patients. Subjects included in the screening program were aged between 45 and 75 years with at least one first-degree relative affected by CRC. They were invited to an interview where a physician suggested colonoscopy as a screening option. RESULTS: In 5 years, 776 subjects were interviewed and 733 (94.4%) agreed to an endoscopic examination (M/F:375/401; mean age 55 years): 562 colonoscopies were performed. Adenomas and cancers were found in 122 (21.7%) and 12 (2.1%) subjects, respectively. Histological examination in 181 persons with lesions (32.8%) showed (most serious lesion quoted) 47 hyperplastic polyps (26% of all lesions), 2 serrated adenomas (1.1%), 68 tubular adenomas (48%), 24 tubulovillous adenomas (13.3%), 9 adenomas with high grade dysplasia (5%) and 12 adenocarcinomas (6.6%). The majority of the cancers were at an early stage (8 Dukes A and 3 Dukes B). Sedation was used in only 42 colonoscopies (7.5%). CONCLUSIONS: A colonoscopy-based screening in this selected high-risk population is feasible. Even without sedation subjects readily agreed to the endoscopic procedure. We identified a significant number of advanced neoplasms and cancers at an early stage suggesting that this could be a useful tool in early identification of CRC.     

Use of colonoscopy as a primary screening test for colorectal cancer in average risk people

OBJECTIVE: The use of colonoscopy as a primary screening test for colorectal cancer (CRC) in average risk adults is a subject of controversy. Our primary objective was to build a predictive model based on a few simple variables that could be used as a guide for identifying average risk adults more suitable for examination with colonoscopy as a primary screening test. METHODS: The prevalence of advanced adenomas was assessed by primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC. Age, gender, and clinical and biochemical data were compared among people without adenomas, those with non-advanced adenomas, and those with any advanced neoplasm. A combined score to assess the risk of advanced adenomas was built with the variables selected by multiple logistic regression analysis. RESULTS: Neoplastic lesions were found in 617 subjects (27.9%), including 259 with at least one neoplasm that was 10 mm or larger, villous, or with moderate-to-severe dysplasia, and 11 with invasive cancers. Advanced lesions were more frequent among men, older people, and those with a higher body mass index (BMI). These three variables were independent predictors of advanced adenomas in multivariate analysis. A score combining age, sex, and BMI was developed as a guide for identifying individuals more suitable for screening colonoscopy. CONCLUSIONS: Age, gender, and BMI can be used to build a simple score to select those average risk adults who might be candidates for primary screening colonoscopy.     

Endoscopic follow-up after colorectal cancer resection: An Italian multicentre study

BACKGROUND: Endoscopic follow-up is advised in patients operated for colorectal cancer due to a high risk for both metachronous colorectal cancer and adenomas. Such issue has been scarcely addressed in Italy. This study aimed to evaluate the incidence of neoplastic lesions at a scheduled endoscopic follow-up and to identify the patients at higher risk of recurrence. METHODS: Colorectal cancer patients diagnosed in the three participating hospitals (one North, one Centre and one South Italy) were scheduled for colonoscopies at 1, 3 and 5 years after surgery. Incidence of adenomas, advanced adenomas and colorectal cancer was assessed in all patients. Neoplastic incidence in patients with and without synchronous lesions at entry was also compared. RESULTS: Overall, 318 consecutive patients were prospectively enrolled including 108 (34%, group A) with a synchronous lesion and 210 (group B) without it. A cumulative neoplastic incidence of 20.1, 32.4 and 44% was observed at 1, 3 and 5 years of follow-up, respectively. The cumulative incidence of all the lesions was 70% in group A and 30.2% in group B at 5-year follow-up, being 39.5 and 15.5% after excluding the lesions detected at 1-year examination. A neoplastic lesion was detected more frequently in group A at 1year (30.5% versus 14.7%; p = 0.0013), 3 years (21.4% versus 7.6%; p = 0.0008) and at 5years (18.1% versus 7.8%; p = 0.02). CONCLUSIONS: Our data showed that the incidence of adenomas in patients operated for colorectal cancer is fairly high. Colorectal cancer patients with synchronous lesions are at higher risk of neoplastic recurrence at follow-up as compared to those without them.     

Colonoscopic yield of colorectal neoplasia in daily clinical practice

AIM： To assess the prevalence and location of advanced neoplasia in patients undergoing colonoscopy, and to compare the yield per indication. METHODS： In a multicenter colonoscopy survey （n = 18 hospitals） in the Amsterdam area （Northern Holland）, data of all colonoscopies performed during a three month period in 2005 were analyzed. The location and the histological features of all colonic neoplasia were recorded. The prevalence and the distribution of advanced colorectal neoplasia and differences in yield between indication clusters were evaluated. Advanced neoplasm was defined as adenoma 〉 10 mm in size, with 〉 25% villous features or with high-grade dysplasia or cancer. RESULTS： A total of 4623 eligible patients underwent a total colonoscopy. The prevalence of advanced neoplasia was 13%, with 281 （6%） adenocarcinomas and 342 （7%） advanced adenomas. Sixty-seven percent and 33% of advanced neoplasia were located in the distal and proximal colon, respectively. Of all patients with right-sided advanced neoplasia （n = 228）, 51% had a normal distal colon, whereas 27% had a synchronous distal adenoma. Ten percent of all colonoscopies were performed in asymptomatic patients, 7% of whom had advanced neoplasia. In the respective procedure indication clusters, the prevalence of rightsided advanced neoplasia ranged from 11%-57%. CONCLUSION： One out of every 7-8 colonoscopies yielded an advanced colorectal neoplasm. Colonoscopy is warranted for the evaluation of both symptomatic and asymptomatic patients.     

Prevalence of clinically important histology in small adenomas.

BACKGROUND & AIMS: The prevalence of advanced histology in small polyps has become a crucial issue in optimizing colorectal cancer screening strategies, especially in view of the advent of computed tomography colonography. We evaluated the prevalence of advanced histology in small and diminutive adenomas to clarify their clinical importance in terms of malignant potential. METHODS: Data were reviewed retrospectively from 3291 colonoscopies performed on asymptomatic patients found to have an adenoma on screening with flexible sigmoidoscopy a few weeks before the colonoscopy or who had a family history of colorectal cancer. All polyps were excised endoscopically and sent for pathology testing. Specimens with advanced histology were confirmed by a second reading. RESULTS: Of the 3291 colonoscopies performed, 1235 colonoscopies yielded a total of 1933 small or diminutive adenomatous polyps. Advanced histology including carcinoma was found in 10.1% of small (5-10 mm) adenomas and in 1.7% of diminutive adenomas (< or = 4 mm). Carcinoma was found in .9% of small adenomas, and 0% of diminutive adenomas. Of the 107 patients found to have polyps 2-10 mm with advanced histology, 100 (93%) were referred for colonoscopy because of an adenoma found on a recent screening with flexible sigmoidoscopy. Seven patients underwent colonoscopy for a positive family history of colon cancer; all 7 had a single affected first-degree relative older than age 50. CONCLUSIONS: Adenomas 5-10 mm in size harbor pathologically significant histology, and the need for removal of these lesions must be addressed to optimize colorectal cancer prevention.