Risk of Advanced Proximal Adenoma and Cancer According to Rectosigmoid Findings in the Korean Population

Colorectal cancer is one of the leading causes of cancer death in the United States and Europe. Recently, the incidence of colorectal cancer has been increasing remarkably in Korea. To reduce the high incidence, screening of colorectal cancer in asymptomatic individuals has been advocated. Sigmoidoscopy is simpler, faster, and better tolerable than total colonoscopy, but the scope cannot reach the proximal colon segment and, therefore, may miss proximal colon cancer. In the present study, we intended to investigate the prevalence of proximal adenoma and cancer according to the findings in rectosigmoid colon and to find their risk factors. Data were collected retrospectively from 1541 consecutive patients who underwent total colonoscopy at the Department of Gastroenterology, Hanyang University, between October 2003 and December 2004. Neoplasms were classified as diminutive adenoma (≤5 mm), small adenoma (6–9 mm), advanced adenoma (≥10 mm, with villous component or high-grade dysplasia), and cancer. The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal (from cecum to descending colon) colon. The prevalence of advanced proximal adenoma was associated with severe rectosigmoid findings. On the other hand, the prevalence of proximal colon cancer did not show such a tendency. Among the 131 patients with proximal advanced adenoma, 66% had no neoplasm in the rectosigmoid colon. Moreover, among the 27 patients with proximal cancer, 52% had no neoplasm in the rectosigmoid colon. Multivariate logistic regression analysis revealed that age, gender, and advanced rectosigmoid adenoma were the risk factors of advanced proximal adenoma, but nothing was associated with the risk for proximal colon cancer. Advanced rectosigmoid adenoma may be the predictor of advanced proximal adenoma, especially in old males. However, nothing is related to the risk for proximal colon cancer. Therefore, colonoscopy may be more adequate for colorectal cancer screening than sigmoidoscopy in the Korean population.     

Rectosigmoid findings are not associated with proximal colon cancer： Analysis of 6 196 consecutive cases undergoing total colonoscopy

AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy. METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males, without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less), small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia) and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon). RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logistic-regression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer. CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.     

Colorectal Adenoma Characteristics as Predictors of Recurrence

PURPOSE The identification of groups with a high risk of colorectal adenoma recurrence remains a controversial issue for clinicians. This study was designed to assess the predictive value of initial patient and adenoma characteristics of the three-year recurrence.METHODS The study population was composed of 552 patients with resected colorectal adenomas who completed the European Fiber-Calcium Intervention trial. At both baseline and three-year examinations, the characteristics of adenomas were recorded according to a standardized protocol. The main outcomes measured were the three-year overall recurrence, recurrence of multiple adenomas, recurrence of advanced adenomas (size 1 cm or tubulovillous/villous architecture or moderate/severe dysplasia), and proximal and distal recurrence.RESULTS A three-year recurrence was observed in 122 patients (22.1 percent), and more than one-half of them had recurrent adenomas on the proximal colon. After adjustment for patient characteristics and treatment allocation, the number of adenomas and their proximal location at baseline were the main predictors of recurrence. In comparison with patients who had one or two adenomas on the distal colon, patients with three or more adenomas with at least one of them located on the proximal colon had a much higher risk of overall recurrence (5.3; 95 percent confidence interval, 2.7–10.3), proximal recurrence (8.5; 95 percent confidence interval, 4.1–18), and advanced adenoma recurrence (5.5; 95 percent confidence interval, 2.4–12.6).CONCLUSIONS Follow-up colonoscopies in patients with adenomas should include careful examination of the proximal colon. The time interval between follow-up examinations could probably be extended beyond three years in patients who have only one or two distal adenomas.Other Investigators in the Study Group are listed in Appendix 1.Supported by the Europe Against Cancer Programme, the Association Contre le Cancer (Brussels), the Association Luxembourgeoise Contre le Cancer, INSERM (France, grant 91-1002), the French Ministry of Health (PHRC), the Deutsches Krebsforschungzentrum, the Danish Cancer Society, the FISS (Spain), Hospital Supplies (Ireland), the University of Coimbra (Portugal), and Istituto Tumori Genova (Italy). The calcium and its placebo treatment were provided by Sandoz France. The fiber and its placebo treatment were provided by Reckitt and Coleman (United Kingdom).     

Incidence of Advanced Adenomas of the Rectosigmoid Colon Three Years and Five Years After Negative Flexible Sigmoidoscopy in 4010 Patients

Flexible sigmoidoscopy is recommended for persons at average risk for colorectal cancer. A follow-up is advised in 3 to 5 years, although the outcomes are not well established. We designed a large, prospective study of an unselected population to measure the incidence of advanced adenomas at flexible sigmoidoscopy 3 and 5 years after an initial negative examination. Adenomas were considered advanced if they were villous, tubulovillous, high-grade dysplasia, adenocarcinoma, or > or = 10 mm in size. We evaluated 8121 patients referred for flexible sigmoidoscopy and 4010 met the inclusion criteria. Group 1 had flexible sigmoidoscopy between 3 and 4 years and Group 2 between 5 and 6 years after a negative examination. Group 1 included 1300 patients with an incidence rate for advanced adenomas of 0.9% (12/1300) and Group 2 included 2710 patients with an incidence rate for advanced adenomas of 1.1% (30/2710). When the two group were subdivided by the presence or absence of a family history of a first-degree relative with sporadic colorectal cancer, the incidence rates for advanced adenomas between the populations were not different. Our data indicate incidence rates of 0.9 and 1.1% for advanced adenomas at flexible sigmoidoscopy 3 and 5 years, respectively, after a negative flexible sigmoidoscopy, with no impact from a family history.     

Predictive value of diminutive colonic adenoma trial: the PREDICT trial.

BACKGROUND & AIMS: Diminutive adenomas (1-9 mm in diameter) are frequently found during colon cancer screening with flexible sigmoidoscopy (FS). This trial assessed the predictive value of these diminutive adenomas for advanced adenomas in the proximal colon. METHODS: In a multicenter, prospective cohort trial, we matched 200 patients with normal FS and 200 patients with diminutive adenomas on FS for age and gender. All patients underwent colonoscopy. The presence of advanced adenomas (adenoma >or= 10 mm in diameter, villous adenoma, adenoma with high grade dysplasia, and colon cancer) and adenomas (any size) was recorded. Before colonoscopy, patients completed questionnaires about risk factors for adenomas. RESULTS: The prevalence of advanced adenomas in the proximal colon was similar in patients with diminutive adenomas and patients with normal FS (6% vs. 5.5%, respectively) (relative risk, 1.1; 95% confidence interval [CI], 0.5-2.6). Diminutive adenomas on FS did not accurately predict advanced adenomas in the proximal colon: sensitivity, 52% (95% CI, 32%-72%); specificity, 50% (95% CI, 49%-51%); positive predictive value, 6% (95% CI, 4%-8%); and negative predictive value, 95% (95% CI, 92%-97%). Male gender (odds ratio, 1.63; 95% CI, 1.01-2.61) was associated with an increased risk of proximal colon adenomas. CONCLUSIONS: Diminutive adenomas on sigmoidoscopy may not accurately predict advanced adenomas in the proximal colon.     

Impact of a Family History of Colorectal Cancer on the Prevalence of Advanced Adenomas of the Rectosigmoid Colon at Flexible Sigmoidoscopy in 3147 Asymptomatic Patients

Flexible sigmoidoscopy is advised as a screening test for colorectal cancer for persons with a family history of late-onset colorectal cancer. The expected outcome for this approach is not well established. We designed a large, prospective study of an unselected population to assess the impact of a family history of one first-degree relative with colorectal cancer on the prevalence of advanced adenomas at screening flexible sigmoidoscopy. We evaluated 8121 patients referred for flexible sigmoidoscopy between 1997 and 1999 and 3147 patients met the inclusion criteria. The 3147 patients were divided into 210 with a family history of colorectal cancer and 2937 without a family history and analyzed for differences in the prevalence of advanced adenomas. Of the 210 with a family history, 3 had an advanced adenoma of the rectosigmoid colon (1.4%) Of the 2937 without a family history, 52 had an advanced adenoma of the rectosigmoid colon (1.8%), including 2 cancers. These differences were not significant. In conclusion, a family history of colorectal cancer had no impact on the prevalence of advanced adenomas in asymptomatic patients at screening flexible sigmoidoscopy. The prevalence rates for advanced adenomas and carcinomas of the rectosigmoid colon were low.     

Diverticular disease as a risk factor for sigmoid colon adenomas

BACKGROUND: Diverticular disease and colorectal neoplasia share similar epidemiological features and risk factors. AIM: To evaluate a possible association between diverticular disease and both adenomas and colorectal cancer in patients undergoing total colonoscopy. METHODS: Overall, 630 consecutive patients were recruited from the 3 Units. Inclusion criteria were age over 45 years and the performance of total colonoscopy. Demographic and clinical data were recorded. Adenomas were defined as advanced when their size was >1 cm in diameter, and/or the percentage of the villous component was >30% and/or high grade dysplasia was present. RESULTS: At endoscopy, 291 (47%) out of 630 patients presented evidence of diverticular disease. Adenomas were found in 92 (31.9%) patients with diverticular disease and in 98 (28.9%) patients without [p=ns]. The prevalence of adenomas located in the sigmoid colon was significantly higher in patients with diverticula than in controls (64.1% vs 41.8%; p<0.05). Similarly, the detection of advanced adenomas located in the sigmoid colon was more likely in patients with diverticula than in controls (59.6% vs 37.5%; p<0.05). Colorectal cancer prevalence was similar in patients with and without diverticula (8.3% vs 7.1%; p=ns), and no difference was detected regarding site, between the two groups. CONCLUSIONS: Patients with diverticular disease have a higher risk of harbouring adenomas and advanced adenomas in the sigmoid colon. This observation should be taken into account in screening and surveillance programmes for colorectal neoplasia.     

Clinical significance of distal colon polyps for the prediction of an advanced proximal neoplasm: the KASID prospective multicenter study

Background/aims The possibility of proximal lesion without distal polyps is a weak point of sigmoidoscopic colon cancer screening, but the clinical significance of distal findings for advanced proximal neoplasm (APN) is uncertain. The aim of this study was to assess the significance of a distal finding as a predictor of APN. Materials and methods Asymptomatic patients ≥50 years old were enrolled from among patients who underwent polypectomy at 11 tertiary medical centers during the Korean Association for the Study of Intestinal Disease prospective study conducted between July 2003 and March 2004. Polyps located distal to the splenic flexure were defined as distal polyps. An advanced neoplasm was defined as a polyp of ≥10 mm in size, and/or with villous features, and/or with high-grade dysplasia, or invasive cancer. Age, gender, and distal polyp size, appearance, and histology were analyzed as risk factors of APN. The sensitivity and positive predictive value of distal polyps for APN were calculated. Results Data from 826 patients were analyzed. Mean patient age was 60.1 years (range 50–86), and 71.3% were men. APN was found in 98 patients, and 45 (45.9%) patients had no distal polyps. Risk factors of APN were a male gender, distal polyp size, and an advanced distal neoplasm. Sensitivities of a distal polyp of ≥10 mm and of an advanced distal neoplasm for APN were both 38.8% with positive predictive values of 13.3 and 14.4%, respectively. Conclusions Although distal colon findings were found to be helpful for predicting APN in asymptomatic patients aged ≥50 years, APN without distal polyps requires careful consideration.     

Difference in the prevalence of advanced colon adenoma between patients with gastric neoplasm and healthy people: A STROBE-compliant study

We compared the prevalence of adenoma and cancerous colon polyps in patients undergoing endoscopic removal or gastric surgery for gastric adenoma or gastric cancer and in healthy individuals.The medical records of 707 patients with gastric neoplasm and 798 age- and sex-matched healthy subjects were retrospectively analyzed between January 2010 and July 2018. The clinicopathological characteristics, prevalence of colorectal neoplasm diagnosed by colonoscopy, and risk factors for colorectal polyps were also investigated.When comparing the two groups, the prevalence of overall colorectal polyps and its distribution was not different between the two groups (54.0% vs.49.5%, P = .079), whereas, the number of colon polyps (1.20 ± 1.71 vs 0.99 ± 1.54, P = .015) and the maximal size (3.53 ± 6.14 vs 2.08 ± 2.88, P < .001) were significantly larger in the gastric neoplasm group. The prevalence of advanced colon adenoma was significantly higher in the gastric neoplasm group (10.7% vs 3.8%, P < .001). Risk factors such as elevated glucose levels and the presence of gastric neoplasm were related to the prevalence of all colon polyps. The presence of gastric neoplasm is an important risk factor for advanced colon polyps.Patients with gastric neoplasms had a significantly higher prevalence of advanced colon adenoma. Advanced colon adenoma is associated with the chain from benign adenomas through malignant altered adenomas to advanced colon cancer. Thus, patients with gastric neoplasm are regarded as a high-risk group for colorectal cancer and are recommended for screening colonoscopy at the time of diagnosis.     

Is there a role for sigmoidoscopy in symptomatic patients? Analysis of a study correlating distal and proximal colonic neoplasias detected by colonoscopy in a symptomatic population

BACKGROUND: Colonoscopy is the gold standard exam to investigate patients with colonic complaints. However, its availability is limited in developing countries. Sigmoidoscopy has been advocated as a first procedure in colorectal cancer screening strategies, in order to select those who need colonoscopy. AIM: To study the correlation between distal and proximal colonic neoplasias in symptomatic patients 50 years or older and patients 40 to 49 years old who underwent colonoscopy at a gastrointestinal endoscopy unit in 1999 and 2000 with the purpose to evaluate its role in a symptomatic population. METHODS: All colonoscopies performed in our Department in 1999-2000 were reviewed. The distal colon was defined as the colonic segment aboral to the splenic flexure. Advanced neoplasias were defined as adenomas larger than 10 millimeters and adenocarcinomas. RESULTS: Of the 2,701 colonoscopies retrieved, 1,125 were enrolled in this study. Prevalence rates for adenoma, advanced adenoma and carcinoma were 28.9%, 4.6% and 4% in the group of 830 patients 50 years or older (mean age 65 years, 491 women). The finding of one small (<10 mm) adenoma in the distal bowel doubled the likelihood of finding a proximal neoplasia (OR = 2.12, 95% CI, 1.27-3.54), and multiple (OR = 3.99, 95% CI, 1.72-9.28) or advanced (OR = 3.73, 95% CI, 1.81-7.7) adenomas increased this risk even further. Of the patients without adenoma or carcinoma in the distal colon, 1.93% had proximal advanced neoplasia. In the group of 40 to 49-year-old patients (n = 395; mean age 44.8 years, 208 women) the prevalence of adenomas (14.9%), advanced adenomas (3.4%), and carcinomas (1.7%) was lower. CONCLUSIONS: The likelihood of finding a proximal lesion is greater in patients with distal neoplasias. This likelihood is further increased when adenomas are multiple or larger than 10 mm. One out of 52 patients 50 years or older with an apparently normal distal colon has advanced proximal neoplasia. Sigmoidoscopy is not an adequate exam for symptomatic patients aged 50 years or older.     

Adenoma characteristics as risk factors for recurrence of advanced adenomas

BACKGROUND AND AIMS: The link between adenoma characteristics at baseline colonoscopy and adenoma recurrence is poorly understood. We assessed whether the number, size, location, or histology of resected adenomas was related to the probability of recurrence of advanced lesions. METHODS: Analyses were based on 1287 men and women in the wheat bran fiber (WBF) study, a randomized, double-blind trial of WBF as a means of decreasing the probability of adenoma recurrence over a period of 3 years. Multiple logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Recurrence of advanced adenomas (>1 cm or tubulovillous/villous histology) was higher among individuals with adenomas >1 cm compared with those with adenomas <0.5 cm (OR, 2.69; 95% CI, 1.34-5.42) and among those with proximal than those with distal adenomas (OR, 1.65; 95% CI, 1.02-2.67). No association was observed for adenoma number or histology. A shift in location from the distal colon and rectum at baseline (54.6%) to more proximal recurrent adenomas (45.2%), including advanced lesions (42.8%), was observed. CONCLUSIONS: Large or proximally located adenomas are important indicators of recurrence of advanced lesions. Because most recurrences were detected in the proximal colon, careful surveillance of this area is warranted.     

Detection rate and proximal shift tendency of adenomas and serrated polyps: a retrospective study of 62,560 colonoscopies

Purpose

The purpose of this study is to estimate the detection rates of adenomas and serrated polyps and to identify proximalization and associate risk factors in patients from Southern China.

Methods

Consecutive patients undergoing colonoscopy from 2004 to 2013 in Guangzhou were included. The proportions of proximal adenomas to advanced adenomas and serrated polyps were compared and potential predictors were evaluated.

Results

Colonoscopies (n?=?62,560) were performed, and 11,427 patients were diagnosed with polyps. Detection rates for adenomas, hyperplastic polyps, and serrated adenomas were 12.0, 2.5, and 0.2 patients per 100 colonoscopies. When comparing the 1st (2004–2008) to the 2nd period (2009–2013), adenoma and serrated polyp detection in proximal and distal colon both increased significantly (proximal colon [adenoma 3.9 vs. 6.1 patients/100 colonoscopies, P?<?0.001; serrated polyp 0.4 vs. 1.1 patients/100 colonoscopies, P?<?0.001]; distal colon [adenoma 6.6 vs. 7.2 patients/100 colonoscopies, P?=?0.003; serrated polyp 1.2 vs. 2.4 patients/100 colonoscopies, P?<?0.001]). Advanced adenoma detection increased over these two periods only in proximal colon (1st vs. 2nd period: 1.5 vs. 2.4 patients/100 colonoscopies, P?<?0.001), not the distal colon (P?=?0.114). Multivariate analyses showed that diagnostic period was an independent predictor for adenoma proximalization (OR?=?1.36, 95% CI 1.25–1.48, P?<?0.001), but not for advanced adenomas (P?=?0.117) or serrated polyps (P?=?0.928).

Conclusions

Adenomas and serrated polyps were increasingly detected throughout the colon, whereas advanced adenomas were only in proximal colon. A proximal shift tendency detected by colonoscopy was observed for adenomas, but not advanced adenomas or serrated polyps, in Southern China. The screening for proximal polyps should be emphasized and colonoscopy might be a preferred initial screening tool.

     

Patient age and duration of colonoscopy are predictors for adenoma detection in both proximal and distal colon

AIM: To investigate the relation of patient characteristics and procedural parameters to the endoscopic detection rate of colonic adenomas. Further to study,which factors may be capable to predict the localization of adenomatous lesions.METHODS: We used the data base of a prospective randomized colonoscopy study(The Colo Cap trial) to identify patients being diagnosed with colon adenoma. Logistic regression analysis was conducted to reveal predictors for adenoma detection in the entire colon and also with respect to the proximal and distal part. Covariates including age, gender, duration of colonoscopy and comorbidities were defined to determine association between predictors and adenoma detection.RESULTS: Equal numbers of adenomas were detected in the proximal and distal side of the splenic flexure [126(57%) vs 94(43%), P = 0.104]. Simultaneous occurrence of adenomas in both sides of the colon was rare. The appearance of both proximal and distal adenoma was associated with increasing age(P = 0.008 and P = 0.024) and increasing duration of colonoscopy(P < 0.001 and P = 0.001). Male gender was a predictor for adenoma detection in the proximal colon(P = 0.008) but statistical significance was slightly missed with respect to the distal colon(P = 0.089). Alcohol abuse was found to be a predictor for the detection of distal adenoma(P = 0.041). CONCLUSION: Increasing age and longer duration of colonoscopy are factors with a strong impact on adenoma detection both in the proximal and distal colon. Since proximal adenomas occurred in absence of distal adenomas, complete colonoscopy should be performed for screening.     

A Case of Lymphangioma Coexistent with Tubular Adenoma in the Descending Colon and a Review of the Literature

Abstract: We recently encountered a case of lymphangioma of the colon which coexisted with a tubular adenoma. The patient was a 71-year-old male who was admitted for physical therapy for lumbago caused by osteoarthritis. He had no evident abdominal symptoms and no weight loss. Although mild anemia and hypoproteinenia were observed, his stool occult blood test was negative and tumor markers revealed no significant changes. A barium enema revealed two elevated lesions in the descending colon. The proximal lesion appeared to be semipedunculated and its form changed following postural changes. The distal lesion was pedunculated. When the patient changed his posture, the head and stalk of the lesion were identified, Both lesions were removed by endoscopic polypectomy. The proximal lesion was histologically diagnosed as being a cavernous lymphangioma, while the distal one was found to be a tubular adenoma. Lymphangioma of the colon is considered to be rare. In Japan, 102 cases including the present case have been reported to date. The coexistence of this disease with neoplasmic lesions of the colon has been reported in 20 cases, including 7 cancer cases and 16 adenoma cases; some cases had overlapping coexistence. The frequency of coexistence of a lymphangioma with cancer or adenoma seems to be rather high. The relationship between lymphangioma and these lesions is unknown. The coexistence of neoplasmic lesions may be accidental. The patients with this coexistence had no characteristic features, except for a high incidence of gastrointestinal bleeding. At least 43% of the coexisting cancers were found in the cecum, the vermiform appendix and the hepatic flexure, indicating the necessity of a detailed examination of the entire colon in cases where a lymphangioma is detected.     

Screening colonoscopy in 40- to 50-year-old first-degree relatives of patients with colorectal cancer is efficient: a controlled multicentre study

Background and aims Persons with a familial risk of colorectal cancer (CRC) account for about 25% of all CRC cases. The adenoma prevalence in relatives of CRC patients 50–60 years of age is 17–34%; data on younger individuals are scarce. Our aim was to prospectively define the adenoma prevalence in 40- to 50-year-old first-degree relatives of CRC patients compared to controls.Patients and methods CRC patients were identified via the regional cancer registry, and their 40- to 50-year-old first-degree relatives (risk group) were invited for screening colonoscopy. Additional probands and controls of the same age were recruited by newspaper articles and radio or television broadcastings. Using high-resolution video colonoscopy, each detected polyp was removed and histopathologically assessed. Each participant completed demographic and epidemiological questionnaires. Results Of 228 subjects in the risk group 36.4% had polypoid lesions compared to 20.9% of 220 controls (p<0.001). Forty-three (18.9%) subjects in the risk group had adenomas compared to 18 (8.2%) in the control group (p=0.001). High-risk adenomas (>10 mm and/or of villous type) were found in 12 persons in the risk group compared to 5 controls (not significant). In the risk group most lesions (52%) were located proximal to the sigmoid colon compared to 29% in controls.Conclusions Subjects between 40–50 years with first-degree relatives with CRC demonstrate a significantly higher prevalence of adenomas than controls, with a tendency towards a more proximal location. These data support a screening colonoscopy in persons with familial risk already between 40 and 50 years.     

Predictive value of morphologic characteristics in rectosigmoid adenomatous polyps for the probability of synchronous polyps or cancer in the proximal colon.

BACKGROUND/AIMS: Sigmoidoscopy is performed more frequently than colonoscopy, especially for screening purposes and searching for colorectal neoplasm. The necessity of colonoscopy in patients with an adenoma ofor=11 mm) polyps. These groups were compared regarding the presence of proximal adenoma and advanced proximal neoplasia (>10 mm adenoma and/or villous histology and/or high grade dysplasia or cancer). Polyps found in the rectum and sigmoid colon were considered as distal polyps and polyps other than these were considered as proximal polyps. RESULTS: In this study, of 1124 consecutive patients who underwent colonoscopy between April 1997 and January 2002, 184 (16%) had 258 adenomatous polyps in the rectosigmoid area. The polyps were diminutive (or=11 mm) in 33 patients. Forty-one of the patients (39%) with diminutive polyps, 20 of the patients (43%) with small polyps and 19 of the patients (57%) with large polyps had neoplasm in the proximal bowel. In these patients, advanced proximal neoplasm was found in 8 (8%), in 6 (13%) and in 11 (33%), respectively. There was no difference regarding the presence of neoplasm in the proximal colon between these groups. The rate of advanced proximal neoplasm was found to be significantly higher in the group with large polyps in the rectosigmoid area than in the groups with small and diminutive polyps (p<0.05). In 104 patients (57%) with polyp(s) in rectum and sigmoid colon, no associated polyp or cancer was encountered in the proximal colon. CONCLUSION: Colonoscopy is indicated when adenomatous polyp, regardless of size, is found on rectosigmoidoscopy performed because of symptoms.     

Advanced distal colonic lesions as predictors of advanced lesions in the proximal colon

The characteristics of adenomas found during sigmoidoscopy have been suggested to predict synchronous adenomas in the proximal colon. Our aim was to examine whether the presence and characteristics of distal colonic lesions are associated with the presence and characteristics of lesions in the proximal colon. We performed a university hospital based case-control study with 3,268 consecutive subjects who received colonoscopy between January 1992 and December 1995. Subjects who had a history of colonic polyps, inflammatory bowel disease, intestinal resection, or had a contraindication against biopsies were excluded. Number size, and histologic characteristics of polyps in the distal and proximal colon were recorded. Advanced lesions were defined as neoplastic lesions with 1 or more of the following features: 1) > or = 1 cm diameter, and/or 2) villous histology, and/or 3) severe dysplasia or carcinoma, and/or 4) > or = 3 lesions. We found that 439 patients had neoplastic lesions in the distal colon only (61.3% with advanced lesions), 198 patients had lesions in the proximal colon only (55.1% advanced), and 197 had lesions in both the distal colon (74.6% advanced) and the proximal colon (55.8% advanced). Distal lesions were significantly more often advanced in patients with synchronous proximal lesions compared with patients with lesions in the distal colon only (odds ratio: 1.9; 95% confidence interval [CI]: 1.3-2.8; p < 0.001). The odds ratios for finding any neoplastic lesion in the proximal colon and an advanced proximal lesion, respectively, were 3.7 (2.6-5.3) (p < 0.001) and 2.2 (1.3-3.7) (p < 0.01) when a nonadvanced lesion was found in the distal colon, and 6.8 (5.3-8.7) (p < 0.001) and 6.7 (4.9-9.0) (p < 0.001) when an advanced lesion was found in the distal colon. Logistic regression analysis revealed number of distal polyps and villous histology as independent predictors of advanced lesions in the proximal colon; size and severe dysplasia were not independent predictors. In conclusion, characteristics of neoplastic lesions in the distal colon predict the presence and characteristics of lesions in the proximal colon.     

Prevalence of Proximal Neoplasms Among Asymptomatic Patients According to Distal Colorectal Findings

Colorectal cancer has been described in association with hyperplastic polyposis. Only half of proximal colon cancers are associated with distal adenomas. To compare the prevalence of proximal and advanced neoplasia between patients with distal hyperplastic polyps only; with distal adenomas with or without hyperplastic polyps; and with no distal polyps, we retrospectively analyzed data of 1,064 adults who underwent colonoscopy. Of these patients, 3% had neoplasia. Proximal neoplasia occurred in 0.8% of 945 patients with no distal polyps, compared to none of 19 with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). Proximal advanced neoplasia occurred in 0.6% patients with no distal polyps, compared with none with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). In conclusion, patients with distal hyperplastic polyps, unlike those with distal adenomas, do not exhibit an increased risk for proximal neoplasia or proximal advanced neoplasia compared to those with no distal polyps.     

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.     

Predictors of advanced proximal neoplasia in persons with abnormal screening flexible sigmoidoscopy.

BACKGROUND & AIMS: The relationship between distal and proximal colonic findings is uncertain. Thus, there is no consensus on which findings on screening flexible sigmoidoscopy should trigger colonoscopy. METHODS: We analyzed data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to assess the relationship between distal and proximal colonic findings. RESULTS: A total of 8802 subjects had an abnormal baseline sigmoidoscopy and colonoscopy follow-up. Subjects with <10-mm single or multiple tubular adenomas had similar risks for advanced proximal neoplasia as subjects with hyperplastic polyps or other benign lesions (3%-5%). Subjects with large (>or=10 mm), villous, or severely dysplastic distal adenomas had similarly elevated risks for advanced proximal neoplasia (11%-12%). Multivariate logistic modeling showed a significantly increased risk for advanced proximal neoplasia associated with the presence of a large tubular (odds ratio [OR], 2.6; 95% confidence interval [CI], 2.0-3.4) or villous distal adenoma (OR, 2.7; 95% CI, 2.1-3.5) but not with the presence of one (OR, 1.05; 95% CI, 0.8-1.3) or multiple (OR, 0.8; 95% CI, 0.5-1.2) <10-mm tubular distal adenomas. CONCLUSIONS: Among subjects with a polypoid lesion on screening flexible sigmoidoscopy, those with small tubular distal adenomas are at similar risk for advanced proximal neoplasia as those without distal adenomas. Subjects with a large, villous, or dysplastic distal adenoma are at increased risk. A strategy that encourages individuals with small tubular adenomas on sigmoidoscopy to undergo follow-up colonoscopy and excludes those with nonadenomatous lesions is of questionable validity, because both groups are at similar risk for advanced proximal neoplasia.