Distal Colonic Polyps Research Articles

Prevention of Bleeding After Endoscopic Resection of Colonic Polyps: to Clip or not to Clip

Endoscopic resection of large colonic lesions once thought only amenable to surgery is now standard treatment, but post-procedure bleeding has been common, occurring in 5–10% of patients. This review summarizes efficacy data on clip closure to reduce bleeding risk, selection of polyps, costs and limitations. Randomized control trials and meta-analysis provide strong evidence for the benefit of prophylactic clip closure to prevent bleeding after endoscopic resection of large ≥ 20-mm proximal polyps, but not for smaller polyps or for large polyps in the distal colon. Clip closure techniques need to be improved, and further research may help to better identify which patients may most benefit from prophylactic closure. Post-procedure bleeding is the most common complication after large polyp resection. Clip closure of the mucosal defect after resection of all proximal 20-mm polyps should be attempted because it reduces bleeding risk by at least half.

Comparative analysis of aldehyde dehydrogenase 1 expression in polyps and adenocarcinoma of the distal colon

Aldehyde dehydrogenase 1 (ALDH1) is one of the most widely used cancer stem cells markers, even though the question of its significance for certain stages of colorectal carcinogenesis is still unclear. The aim of this study was to compare ALDH1 immunohistochemical expression levels in polyps and adenocarcinoma of the distal colon. Histopathological and immunohistochemical studies of biopsies from 40 patients (biopsies of polyps and histologically non-changed mucosa of the distal colon), as well as surgical material of colorectal adenocarcinoma from 30 patients were carried out. It was established that distal colonic polyps are characterized by cytoplasmic expression of ALDH1 with the median of relative area that is equal to 25.63 (18.26; 30.42)% stromal cells. ALDH1 expression by epitheliocytes is revealed exclusively in dysplastic polyps with the median of the area that is equal to 22.13 (17.22; 30.05)%. Colorectal adenocarcinoma is characterized by cytoplasmic expression of ALDH1 with the medians of the area that are equal to 40,22 (22,54; 47,77)% stromal cells and 32,12 (23.64; 40.28)% cancer cells. The area of ALDH1+ cells varies depending on the pTNM stage of the carcinoma, herewith the median of ALDH1+ stromal cells is significantly increasing during the tumor progression from the I to the III stages that displays increasing in number of stromal cells which are involved in oncogenic signaling pathways activation. The median of ALDH1+ cancer cells is significantly increasing during the tumor progression from the III to the IV stages that shows increasing number of cancer cells that acquire properties of stem cells on advanced stages of colorectal adenocarcinoma. Comparative analysis of the parameters obtained for polyps and carcinoma indicates that the median of ALDH1+ stromal cells area in polyps is 2 times smaller than the median of ALDH1+ stromal cells area in carcinoma, and the median of ALDH1+ epitheliocytes area in polyps is 1.5 times smaller than the median of ALDH1+ cancer cells area.

COMPARATIVE ANALYSIS OF CD44 EXPRESSION IN POLYPS AND ADENOCARCINOMA OF DISTAL COLON

Introduction. CD44 is one of the most used markers of cancer stem cells in colorectal cancer. Even though, the questions of its diagnostic and prognostic value remain open. The aim of the study was to compare CD44 immunohistochemical expression levels in polyps and adenocarcinoma of the distal colon. Materials and methods. Histopathological and immunohistochemical studies of biopsies from 40 patients and surgical material of colorectal adenocarcinoma from 30 patients were carried out. Results. It was figured out that distal colonic polyps are characterized by membranous CD44 expression with the medians of relative areas of CD44+ cells equal to 60,24 (50,22; 70,22) % stromal cells and 15,67 (12,47; 19,47) % epitheliocytes. Colorectal adenocarcinoma is characterized by membranous-cytoplasmic CD44 expression with the medians of relative areas of CD44+ cells equal to 61,26 (42,58 ; 79,15) % stromal cells and 30,60 (24,56 ; 36,45 ) % cancer cells. Comparative analysis of the data obtained for the pTNM stages of colorectal adenocarcinoma revealed some significant differences. The median of CD44+ stromal cells area on the I stage equals to 31,41 (19,87 ; 42,15) % vs. the median of CD44+ stromal cells area on the II stage equals to 48,26 (35,44 ; 61,45) % , р ˂ 0,05; the median of CD44+ stromal cells area on the II stage vs. the median of CD44+ stromal cells area on the III stage equals to 78,36 (61,13 ; 80,06) % , р ˂ 0,05. The median of CD44+ cancer cells area on the III stage equals to 30,35 (21,19 ; 35,47) % vs. the median of CD44+ cancer cells area on the IV stage equals to 31,25 (30,22 ; 41,19) % , р ˂ 0,05. Moreover, it was revealed that the median of CD44+ epitheliocytes area in polyps two-fold smaller than the median of CD44+ cancer cells area in colorectal adenocarcinoma: 15,67 (12,47 ; 19,47) % vs. 30,60 (24,56 ; 36,45 ) % , р ˂ 0,05. Conclusions. Distal colonic polyps are characterized by membranous CD44 expression with the median of CD44+ epitheliocytes area that is two-fold smaller than the median of CD44+ cancer cells area. Colorectal adenocarcinoma is characterized by membranous-cytoplasmic CD44 expression with the median of CD44+ stromal cells area that significantly increases during the tumor progression from I to III stages and with the median of CD44+ cancer cells area that significantly go up during the tumor progression from III to IV stages.

Analysis of proliferation and apoptosis, MUC-1 and Cdx-2 expression in distal colonic polyps

Background. The universal molecular characteristics of malignancy are activation of cell proliferation and inactivation of apoptotic cell death. Besides genes-regulators of the processes other molecules are involved, including mucins and Cdx-2. Aim . To conduct comparative and correlation analysis of indexes of immunohistochemical expression of Ki-67, p53, caspase-3, as well as MUC-1 and Cdx-2 in distal colonic polyps. Methods. Pathohistological and immunohistochemical studies of biopsies of adenomas and hyperplastic polyps from 40 patients were carried out. Results. Distal colonic polyps are characterized by medium proliferation level: the median of Ki-67 expression for hyperplastic polyps is 42,20 (35,27; 52,38) %, while the median for adenomas is 65,39 (52,28; 76,23) % (р˂0,05). The polyps are characterized by low p53 expression levels: the median of the marker expression for hyperplastic polyps is 1,53 (1,17; 3,16) %, for adenomas – 9,15 (8,26; 12,39) % (р˂0,05). The studied polyps are characterized by low apoptosis levels: the median of caspase-3 expression for hyperplastic polyps is 33,78 (30,28; 42,34) CUOD, for adenomas – 22,19 (16,84; 40,51) CUOD (р˂0,05). Distal colonic polyps are characterized by medium MUC-1 and Cdx-2 expression levels: the medians of the markers expression for hyperplastic polyps are 62,13 (34,20; 71,85) CUOD and 71,81 (62,36; 77,77) CUOD, for adenomas – 80,25 (52,14; 95,21) CUOD and 95,14 (81,19; 112,17) CUOD, respectively (р˂0,05). The correlation analysis revealed several correlations: reverse medium strength correlation between p53 and caspase-3 expression levels (r = -0,57, р˂0,05), direct medium strength correlation between caspase-3 and MUC-1 expression levels (r = 0,52, p˂0,05) take place in hyperplastic polyps, whereas reverse strong correlation between caspase-3 and MUC-1 expression levels 1 (r = -0,88, p˂0,05) takes place in adenomas. Conclusions. Distal colonic adenomas differ by higher proliferation and p53 expression levels, comparing to hyperplastic polyps, and by lower apoptosis level that is associated with higher MUC-1 expression level as well. Hyperplastic polyps differ by higher apoptosis level that is associated with lower MUC-1 expression level. Cdx-2 expression increases on benign adenoma stage and does not correlate with proliferation and apoptosis indexes.

An unusual case of Peutz–Jeghers syndrome with polyposis-associated adenomatous change

Introduction: Peutz–Jeghers syndrome (PJS) is a rare autosomal dominant syndrome associated with mucocutaneous pigmentation and hamartomatous gastrointestinal polyps. It is associated with increased risk of intestinal and extraintestinal malignancies. Case Report: This is a rare case of PJS with multiple polyps with features of villous adenoma and high grade dysplasia. A 48-year-old female presented with the complaints of bleeding per rectum since five months. Hyperpigmented spots were present on the buccal mucosa. On endoscopy, multiple polyps in distal colon, stomach, duodenum, and periampullary region were noted. Polypectomy was done and sent for histopathological evaluation. Grossly, the largest polyp was in sigmoid colon measuring 2.6 × 1.5 × 1 cm and smallest polyp was in stomach measuring 3 × 2 × 1 mm. On microscopy, polyps from transverse colon showed polypoidal tissue traversed by branching muscularis mucosae forming arborizing pattern. Polyps from sigmoid colon showed similar features with a focus of dysplasia and villous adenoma. Conclusion: Further the patient was advised to undergo mandatory periodic evaluation on follow-up.

Comparative immunohistochemical study of neoangiogenesis in polyps and adenocarcinoma of the distal colon.

Background. Neoangiogenesis provides trophic support for neoplastic cells, thus being an integral part of carcinogenesis. However, the features of neoangiogenesis in the most common distal colonic polyps and carcinoma are not completely studied yet. Objective. To compare VEGF-A, VEGFR-1, VEGFR-2, CD34 expression levels in distal colonic polyps and colorectal adenocarcinoma. Methods. Pathomorphological and immunohistochemical studies of biopsies of distal colonic polyps from 30 patients and surgical material of colorectal adenocarcinoma from 40 patients were carried out. Results. Distal colonic polyps are characterized by medium and low levels of VEGF-A, VEGFR-2 and CD34 expression. Wherein, VEGF-A and VEGFR-2 expression levels in adenomas are significantly higher than the same indicators in hyperplastic polyps: 25,51 (15,25 ; 30,19) vs. 12,82 (10,85 ; 15,00) CUOD and 47,18 (42,02 ; 62,13) vs. 37,08 (30,19 ; 45,12) CUOD, accordingly, p < 0,05. Comparative analysis of the data, obtained for distal colonic polyps and colorectal adenocarcinoma of the I stage shows significant difference between these groups by indicators of VEGF-A expression level and microvascular density, evaluated by CD34 expression. So, VEGF-A expression level in carcinoma of the I stage significantly higher the same indicator in adenomas and hyperplastic polyps: 37,80 (30,22; 56,89) vs. 25,51 (15,25 ; 30,19) CUOD and 37,80 (30,22; 56,89) vs. 12,82 (10,85 ; 15,00) CUOD, accordingly, p < 0,05. Microvascular density is significantly higher in non-invasive cancer in comparison to the polyps: 91,50 (51,00; 111,00) vs. 47,00 (33,00 ; 54,00) (adenomas) and 91,50 (51,00; 111,00) vs. 46,00 (30,00 ; 55,00) (hyperplastic polyps), p < 0,05. Conclusion . Adenomas in comparison to hyperplastic polyps are differ by significantly higher VEGF-A and VEGFR-2 expression levels, while colorectal adenocarcinoma of the I stage in comparison to distal colonic polyps differs by significantly higher VEGF-A and CD34 expression expression levels. Activation of neoangiogenesis occurs at the stage of transformation of distal colon polyps into non-invasive cancer.

Comparative immunohistochemical study of ki-67, p53, caspase-3 in distal colonic polyps and colorectal adenocarcinoma.

Background. Colorectal carcinogenesis is a multistep process that begins from the normal epithelium and includes the step of adenoma formation. The question of diagnostic and prognostic value of proliferation and apoptosis markers for the distal colorectal neoplasms is still open. Objective. To compare Ki-67, p53, caspase-3 expression levels in distal colonic polyps and colorectal adenocarcinoma. Methods. Pathomorphological and immunohistochemical studies of biopsies of distal colonic polyps from 30 patients and surgical material of colorectal adenocarcinoma from 30 patients were carried out. Results. Ki-67 expression level by epitheliocytes of hyperplastic polyps is 1.5 times lower than that for adenocarcinoma [26.23 (22.16, 48.88) % vs. 41.20 (36.62, 59.42) %], but adenomas are distinguished by 1.5 times higher Ki-67 expression level in comparison with adenocarcinoma [62.40 (48.65, 76.23) % vs. 41.20 (36.62, 59.42) %]. Caspase-3 expression level by hyperplastic polyps epitheliocytes is 1.7 times lower than that for adenocarcinoma [16.99 (11.86, 39.85) CUOD vs. 28.72 (15.84, 76.71) CUOD], but caspase-3 expression level by epitheliocytes of adenomas is 1.1 times higher than that for cancer cells [31.84 (19.53, 42.34) CUOD vs. 28.72 (15, 84; 76.71) CUOD]. The maximum proliferation and apoptosis levels were revealed for high-grade [76.23 (62.36, 85.36) % and 42.34 (33.78, 65.38) CUOD] and villous [79.09 (69.12, 84.27) % and 67.88 (63.92, 71.29) CUOD] adenomas. p53 expression level by epithelial cells of hyperplastic polyps almost is 40 times lower than that for adenocarcinoma [0.00 (0.00; 1.47) % vs. 39.67 (15.69, 83.75) %], and p53 expression level by epitheliocytes of adenomas is 16.5 times lower than that for cancer cells [2.39 (1.58, 8.26) % vs. 39.67 (15.69, 83.75) %]. Conclusion. The high levels of proliferation and apoptosis of epitheliocytes characterize the polyps-precursors of colorectal carcinoma that have the biggest malignant potential. Colorectal adenocarcinoma differs by the medium p53 expression level by tumor cells.

MUC1, MUC2, MUC4, MUC5AC, Cdx2: immunohistochemical characteristics in polyps and adenocarcinoma of distal colon

Aim – to study MUC1, MUC2, MUC4, MUC5AC, Cdx2 immunohistochemical expression in polyps and adenocarcinoma of distal colon. Materials and methods. Pathomorphological and immunohistochemical studies of biopsies from 30 patients, which underwent colonoscopy with polypectomy, and surgical material from 30 patients, which underwent surgery for colorectal adenocarcinoma, were carried out. Results. Distal colonic polyps are different from unchanged mucosa by increased MUC-1 expression. Maximum expression levels of the marker are observed in serrated adenomas, which are characterized by high MUC-1 expression level. Median of MUC-1 expression in adenocarcinoma is greater than that in unchanged mucosa, however, less than in polyps. Comparative analysis of data of the study of MUC2 expression indicates that the maximum expression of the marker is characteristic of unchanged mucous membrane. Polyps are distinguished by lower MUC2 expression levels; among them, highest expression levels are observed in hyperplastic polyps, lesser – in serrated adenomas and adenomas. Distal colonic carcinoma has extremely low median of MUC2 expression. The highest levels of MUC4 expression are observed in hyperplastic polyps, somewhat lower – in unchanged mucosa. Serrated adenomas, adenomas and adenocarcinomas differs by lower MUC4 expression levels. The minimum level of the marker expression is observed in serrated adenomas. In polyps MUC5AC expression levels are greater than in adenocarcinoma. Expression of this marker is not detected in unchanged mucosa. The maximum median of MUC5AC expression is observed in serrated adenomas, which are characterized by high level of the marker expression, somewhat lower – in adenomas, and more lower in hyperplastic polyps. High Cdx-2 expression level characterizes serrated adenomas and adenocarcinoma. The average Cdx-2 expression level is observed in adenomatous polyps, hyperplastic polyps, and unchanged mucosa, with the medians of the marked expression decreasing in that sequence. Conclusions . Distal colon polyps are characterized by increased MUC1 and Cdx-2 expression levels, with parallel decrease of MUC2 expression level and aberrant MUC5AC expression. At the same time, serrated adenomas are distinguished by the greatest deviations of the studied markers expression levels. Adenocarcinoma of the distal colon, compared with polyps, is characterized by decrease of MUC1, MUC2 and MUC5AC expression levels.

Distal colonic polyps: immunohistochemical study of proliferation and apoptosis

Background. It’s well known that colonic polyps can be precursors of colorectal cancer. But exact immunohistochemical parameters, including proliferation and apoptosis levels of polyps’ cells, that may have prognostic value, still not known. Objective. To study the features of immunohistochemical expression of proliferation and apoptosis markers by distal colonic polyps’ cells. Methods. Pathomorphological and immunohistochemical studies of biopsies of distal colonic polyps from 30 patients (the age ranged from 41 to 83 years) were carried out. Results. Distal colonic polyps are characterized by the medium proliferation level of epithelial cells [Me=62.40% (48.65; 76.23) for adenomas, Me=26.23% (22.19; 48.88) for hyperplastic polyps], the low proliferation level of stromal cells [Me=2.94% (1.23; 4.35) for adenomas, Me=1.18% (1.10; 1.86) for hyperplastic polyps], the low p53 expression level of epithelial and stromal cells [Me=2.39% (1.58; 8.26) and Me=1.23% (0.72; 1.49) for adenomas’ cells, Me=0,00% (0,00; 1,47) and Me=0,00% (0,00; 0,05) for hyperplastic polyps’ cells], and also by the low apoptosis level of epithelial and stromal cells [Me=31.84CUOD (19.53; 42.34) and Me=43.87CUOD (25.47; 73.09) for adenomas, Me=16.99CUOD (11.86; 39.85) and Me=28.64CUOD (19.20; 30.71) for hyperplastic polyps]. There are direct correlations between the expression levels of proliferation and apoptosis markers and also the dysplasia grade of the distal colonic adenomas: between the Ki-67 expression levels of epithelial and stromal cells and also the dysplasia grade (γ=0.65 and γ=0.70, respectively), between the p53 expression level of epithelial cells and the dysplasia grade (γ=0.53), between the caspase-3 expression levels of epithelial and stromal cells and also the dysplasia grade (γ=0.80 and γ=0.63, respectively). Moreover, there are direct correlations between the expression levels of proliferation and apoptosis markers of distal colonic polyps’ epitheliocytes: between the Ki-67 and p53 expression levels (r=0.71 for adenomas, r=0.79 for hyperplastic polyps), between the Ki-67 and caspase-3 expression levels (r=0.61 for adenomas), between the p53 and caspase-3 expression levels (r=0.59 for adenomas, r=0.79 for hyperplastic polyps). Conclusion. These data indicate the close association between the processes of proliferation, accumulation of p53 protein, and apoptosis of the distal colonic polyps’ cells.

Su1247 Postcolonoscopy Colorectal Cancer (PCCRC) in a Population of a Closed System of Health Care Provision

BACKGROUND: Previous studies have demonstrated that patients post cholecystectomy have had no definitive association with colorectal adenomatous polyps. It is thought that chronic inflammation from bile acids may lead to increase development of colorectal polyps. Post cholecystectomy chronic diarrhea is likely from bile acid exposure. Additionally chronic constipation is thought to be an risk factor for colorectal cancer. The purpose of this study is to investigate for an increased risk for colorectal adenomas in post cholecystectomy patients and to look for the association of polyps with chronic diarrhea in these patients. METHODS: We performed a retrospective chart review of the patients who underwent cholecystectomy between 01/200112/2012 who also had a colonoscopy following surgery. Patients without a personal history of IBD, colorectal polyps and/or family history of colorectal cancer were included in the study. Patients were further divided into two groups, those with and without chronic diarrhea. Polyps were further classified based on histology and location. RESULTS: A total of 395 patients were included in the study (63% female, with a mean age of 50 y). The average number of years between the cholecystectomy and a colonoscopy was 2.6 years. An increased risk for colorectal polyps 151(38%) (95% confidence interval (CI)-0.33-0.43) was found among these patients when compared to an average risk in general population aged 50 y (20%). A total of 28% patients in the study were found to have proximal colon polyps (0.28, 95% CI 0.21 to 0.36) and no significant difference was found when compared to the average risk population (13-37%). In contrast an increased risk of polyps in distal colon 48% (0.48, 95% CI: 0.40 to 0.56) was found when compared to the average risk population (25-40%). Twenty five percent of patients had polyps in both proximal and distal colon 37/151 (0.25; 95% CI 0.18 to 0.32), statistics were not compared to the general population. Hyper plastic polyps were found in 37% (0.37, 95%CI: 0.29 to 0.45) patients, which were not found to be at increased risk when compared to average risk (20-40%). Adenomas, 55% (0.55, 95% CI: 0.46 to 0.63), were found to be at increased risk when compared to average risk (25-30%). Additionally an increased risk was found for serrated polyps, 9% (0.09, 95% CI 0.05 to 0.15), when compared to average risk (1-7%). In patients with chronic diarrhea the proportion of polyps was 0.26 compared to 0.43 in those without chronic diarrhea. (Odds ratio=0.47, 95% CI 0.29-0.75, P=0.002), revealing a negative association of polyps with chronic diarrhea in this set of patients. CONCLUSIONS: Cholecystectomy was found to increase the risk for distal colorectal adenomas/polyps. Chronic diarrhea was found to be negatively associated with colorectal polyps in this set of patients.

Su1245 Post Cholecystectomy, Choleretic Diarrhea Has a Negative Statistical Association With Distal Adenomatous Colorectal Polyps

BACKGROUND: Previous studies have demonstrated that patients post cholecystectomy have had no definitive association with colorectal adenomatous polyps. It is thought that chronic inflammation from bile acids may lead to increase development of colorectal polyps. Post cholecystectomy chronic diarrhea is likely from bile acid exposure. Additionally chronic constipation is thought to be an risk factor for colorectal cancer. The purpose of this study is to investigate for an increased risk for colorectal adenomas in post cholecystectomy patients and to look for the association of polyps with chronic diarrhea in these patients. METHODS: We performed a retrospective chart review of the patients who underwent cholecystectomy between 01/200112/2012 who also had a colonoscopy following surgery. Patients without a personal history of IBD, colorectal polyps and/or family history of colorectal cancer were included in the study. Patients were further divided into two groups, those with and without chronic diarrhea. Polyps were further classified based on histology and location. RESULTS: A total of 395 patients were included in the study (63% female, with a mean age of 50 y). The average number of years between the cholecystectomy and a colonoscopy was 2.6 years. An increased risk for colorectal polyps 151(38%) (95% confidence interval (CI)-0.33-0.43) was found among these patients when compared to an average risk in general population aged 50 y (20%). A total of 28% patients in the study were found to have proximal colon polyps (0.28, 95% CI 0.21 to 0.36) and no significant difference was found when compared to the average risk population (13-37%). In contrast an increased risk of polyps in distal colon 48% (0.48, 95% CI: 0.40 to 0.56) was found when compared to the average risk population (25-40%). Twenty five percent of patients had polyps in both proximal and distal colon 37/151 (0.25; 95% CI 0.18 to 0.32), statistics were not compared to the general population. Hyper plastic polyps were found in 37% (0.37, 95%CI: 0.29 to 0.45) patients, which were not found to be at increased risk when compared to average risk (20-40%). Adenomas, 55% (0.55, 95% CI: 0.46 to 0.63), were found to be at increased risk when compared to average risk (25-30%). Additionally an increased risk was found for serrated polyps, 9% (0.09, 95% CI 0.05 to 0.15), when compared to average risk (1-7%). In patients with chronic diarrhea the proportion of polyps was 0.26 compared to 0.43 in those without chronic diarrhea. (Odds ratio=0.47, 95% CI 0.29-0.75, P=0.002), revealing a negative association of polyps with chronic diarrhea in this set of patients. CONCLUSIONS: Cholecystectomy was found to increase the risk for distal colorectal adenomas/polyps. Chronic diarrhea was found to be negatively associated with colorectal polyps in this set of patients.

Diagnostic value of distal colonic polyps for prediction of advanced proximal neoplasia in an average-risk population undergoing screening colonoscopy.

For colorectal cancer screening, the predictive value of distal findings in the ascertainment of proximal lesions is not fully established. The aims of this study were to assess distal findings as predictors of advanced proximal neoplasia and to compare the predictive value of endoscopy alone vs. combined endoscopic and histopathologic data. Primary colonoscopy screening was performed in 2210 consecutive, average-risk adults. Age, gender, endoscopic (size, number of polyps), and histopathologic distal findings were used as potential predictors of advanced proximal neoplasms (i.e., any adenoma > or =1 cm in size, and/or with villous histology, and/or with severe dysplasia or invasive cancer). Polyps were defined as distal if located in the descending colon, the sigmoid colon, or the rectum. Those in other locations were designated proximal. Neoplastic lesions, including 11 invasive cancers, were found in 617 (27.9%) patients. Advanced proximal neoplasms without any distal adenoma were present in 1.3% of patients. Of the advanced proximal lesions, 39% were not associated with any distal polyp. Older age, male gender, and distal adenoma were independent predictors of advanced proximal neoplasms. The predictive ability of a model with endoscopic data alone did not improve after inclusion of histopathologic data. In multivariate logistic regression analysis, the predictive ability of models that use age, gender, and any combination of distal findings was relatively low. The proportion of advanced proximal neoplasms identified if any distal polyp was an indication for colonoscopy was only 62%. A strategy in which colonoscopy is performed solely in patients with distal colonic findings is not effective screening for the detection of advanced proximal neoplasms in an average-risk population.

Small early tubular adenomas and mixed colonic polyps found on screening flexible sigmoidoscopy do not predict proximal neoplasia in males

Background & Aims : Distal colonic adenomas found on flexible sigmoidoscopy are associated with proximal neoplasias, thus requiring a complete colonoscopic examination, but data regarding the association of distal mixed polyps with proximal neoplasia are lacking. We conducted this study to elucidate the significance of distal mixed colonic polyps in predicting proximal neoplasia. Methods : We retrospectively analyzed data from patients who underwent a flexible sigmoidoscopic examination for colorectal cancer screening and a follow-up colonoscopic examination because of distal colonic polyps. Distal index polyps were classified by a pathologist as early tubular adenoma (ETA), serrated, or true mixed categories. Index polyps also were immunostained with a monoclonal antibody, Adnab-9, a marker for the colorectal adenoma carcinoma sequence. Results : In 636 patients with distal index polyps, 6% were malignant, 55% were adenomas, 13% were ETAs, 6% were serrated, 4% were true mixed, and 17% were hyperplastic. Compared with distal hyperplastic index polyps, distal malignant polyps ( P = 0.0006) and adenomas ( P = 0.001) were associated with a significantly increased number of synchronous proximal neoplasia, but the small distal mixed, serrated, or ETA did not predict the increased incidence of proximal neoplasia. Large distal polyps of each category were significantly associated with an increased number of synchronous proximal neoplasias. In support of these findings, immunostaining of distal polyps with Adnab-9 showed predictability for proximal neoplasia only in the adenoma category ( P < 0.05). Conclusions : Small ETAs, serrated, or mixed polyps found on flexible sigmoidoscopic examination do not increase the probability of synchronous proximal neoplasia.

4493 Prediction of proximal colonic adenomas in patients with distal colonic polyps found on sigmoidoscopy: a prospective controlled study.

Background & Aim: The significance of distal adenomas as a predictor of proximal neoplasms has remained controversial. Most studies to address this issue did not include a control group. The aim of this study was to examine whether rectosigmoid polyps could be markers for proximal lesions considering their size, number and pathology. Methods: A total of 367 asymptomatic patients with distal colonic polyps (314 adenomatous; 53 hyperplastic) noted on sigmoidoscopy and 83 asymptomatic controls without distal colonic polyps were prospectively evaluated with total colonoscopy from Mar 1998 to Oct 1999. No one had risk factors of colorectal cancers or polyps and had undergone barium enema or colonoscopy within five years before inclusion. The mean age (± SD) of the patients and controls was 52.5 ± 10.1 and 51.0 ± 8.7 years, respectively. Advanced adenomas were defined as adenomas >10 mm in diameter or with histology of villous or high grade dysplasia, and diminutive adenomas as 5 mm or less in size. Results: A greater percentage of patients with distal adenomas had synchronous proximal adenomas compared with those with distal hyperplastic polyps and the control group (30.3% vs 17.0% and 15.7%, p

The Relation Between Distal and Proximal Colonic Polyps.

A recent study concluded that patients with a small, distal, tubular adenoma at sigmoidoscopy have a very low prevalence of advanced proximal polyps; those authors raised the question of whether such patients need full colonoscopy ( JW vol. 18, p.xx, accession number 98082501, …

The Controversy Regarding Distal Hyperplastic Polyps

Hyperplastic polyps are non-neoplastic and are fundamentally distinct from adenomas. Currently available data suggest that, at most, distal colonic hyperplastic polyps are weak markers for small proximal adenomas in asymptomatic persons. There are insufficient data at this time to support distal hyperplastic polyps alone as an indicator for colonoscopy.

Significance of Distal Polyps Detected With Flexible Sigmoidoscopy in Asymptomatic Patients

Colorectal cancer is a frequent cause of death from cancer. To reduce the mortality associated with this disease, regular flexible sigmoidoscopy is recommended. However, the significance of diminutive polyps (adenomatous or hyperplastic) detected during flexible sigmoidoscopy remains controversial, as does the appropriate endoscope length (35 vs 60 cm) for colorectal cancer screening. One hundred one consecutive patients with no history of colonic disease, gastrointestinal tract symptoms, or positive results of fecal occult blood testing underwent flexible sigmoidoscopy as part of a colorectal cancer screening program. All patients with distal polyps detected during flexible sigmoidoscopy underwent colonoscopy. More than 25% of these asymptomatic, predominantly male subjects had colonic neoplasms or polyps detected. Fifty percent more lesions could be detected with a 60-cm sigmoidoscope than with a 35-cm sigmoidoscope, and detection of any distal polyp, whether adenomatous or hyperplastic, was associated with at least one proximal colon adenoma in 20% of patients. "Extended flexible sigmoidoscopy" for colorectal cancer screening was well tolerated by patients, as evidenced by insertion to the hepatic flexure in 25% of patients, and provided significantly more information than could be obtained with a 35-cm sigmoidoscope. Colorectal cancer screening should be performed with a 60-cm flexible sigmoidoscope, and distal colonic polyps or neoplasms will be detected in 25% of asymptomatic patients.

Significance of distal polyps detected with flexible sigmoidoscopy in asymptomatic patients

Colorectal cancer is a frequent cause of death from cancer. To reduce the mortality associated with this disease, regular flexible sigmoidoscopy is recommended. However, the significance of diminutive polyps (adenomatous or hyperplastic) detected during flexible sigmoidoscopy remains controversial, as does the appropriate endoscope length (35 vs 60 cm) for colorectal cancer screening.One hundred one consecutive patients with no history of colonic disease, gastrointestinal tract symptoms, or positive results of fecal occult blood testing underwent flexible sigmoidoscopy as part of a colorectal cancer screening program. All patients with distal polyps detected during flexible sigmoidoscopy underwent colonoscopy.More than 25% of these asymptomatic, predominantly male subjects had colonic neoplasms or polyps detected. Fifty percent more lesions could be detected with a 60-cm sigmoidoscope than with a 35-cm sigmoidoscope, and detection of any distal polyp, whether adenomatous or hyperplastic, was associated with at least one proximal colon adenoma in 20% of patients. "Extended flexible sigmoidoscopy" for colorectal cancer screening was well tolerated by patients, as evidenced by insertion to the hepatic flexure in 25% of patients, and provided significantly more information than could be obtained with a 35-cm sigmoidoscope.Colorectal cancer screening should be performed with a 60-cm flexible sigmoidoscope, and distal colonic polyps or neoplasms will be detected in 25% of asymptomatic patients.

Distal colonic hyperplastic polyps do not predict proximal adenomas in asymptomatic average-risk subjects

The significance of distal colonic hyperplastic polyps was investigated in 482 asymptomatic average-risk subjects, aged 50–75 years, in whom fecal occult blood test results were negative and who underwent screening colonoscopy. The incidence of adenomas in the colon proximal to the sigmoid-descending colon junction in subjects with hyperplastic polyps distal to that point was 18% and was similar to the incidence of proximal colonic adenomas in subjects with no distal colonic polyps (15%). The incidence of proximal colonic adenomas in subjects with distal colonic adenomas was 38% and was significantly greater than the incidence found in individuals with no distal colonic polyps or only hyperplastic polyps. Our data do not support distal colonic hyperplastic polyps as markers for proximal colonic adenomas in asymptomatic average-risk subjects.

Distal and Proximal Colon Adenomas

To the Editors: In the report of their prospective study of whether distal colonic hyperplastic polyps are a marker for proximal adenomatous polyps in symptomatic patients, Provenzale and colleague...