Hyperplastic Colonic Polyps as a Marker for Adenomatous Colonic Polyps

Hyperplastic colonic polyps are generally regarded as being of little or no clinical consequence. Recently, however, hyperplastic polyps have been found to share numerous functional similarities with colorectal carcinoma. To determine whether the presence of an isolated left-sided colonic hyperplastic (metaplastic) polyp could serve as a marker for more proximal synchronous adenomatous colonic polyps, we retrospectively analyzed all consecutive colonoscopic polypectomies performed over an 18-month period at two medical centers. It is the policy at both institutions to remove or biopsy all polyps, regardless of size. Indications for colonoscopy included known or previous colonic polyps or carcinoma, hemoccult positive stool, lower gastrointestinal bleeding, iron deficiency anemia, abnormal barium enema, inflammatory bowel disease, abdominal pain, and family history of colon cancer. The location of adenomatous polyps and hyperplastic polyps was recorded and compared. One hundred sixty-three of 845 consecutive patients (19.3%) had at least one colonic polyp. The prevalence of adenomatous polyps alone was 10.3%, hyperplastic polyps 9%, and both types 1.9%. The prevalence rate for an adenomatous polyp in patients without a hyperplastic polyp was 15%. In contrast, among patients with a hyperplastic polyp, 49% had a synchronous adenomatous polyp. Only 3.4% of patients had an adenomatous polyp proximal to the splenic flexure when no polyps were present in the left colon. Conversely, among the 29 patients in whom an isolated hyperplastic polyp was found in the left colon, there was a 32.5% prevalence of adenomatous polyps in the proximal colon (p less than 0.01). The results of this study suggest that left-sided hyperplastic colonic polyps (generally within the reach of a screening sigmoidoscopy) serve as a marker for neoplastic polyps.     

Detection of proximal adenomatous polyps with screening sigmoidoscopy: a systematic review and meta-analysis of screening colonoscopy

BACKGROUND: The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. To address this, we performed a systematic review and meta-analysis of screening colonoscopy studies. METHODS: Published studies through July 31, 2000, of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. We generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia. RESULTS: Using the sigmoid-descending colon junction to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [CI], 1.42-4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio, 2.36; 95% CI, 1.30-4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio, 1.44; 95% CI, 0.79-2.62). The prevalence of isolated advanced proximal neoplasia in the 3 studies was 2%, 3%, and 5%. Using the sigmoid-descending colon junction to identify the beginning of the distal colon yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI, 13.6%-19.1%). CONCLUSIONS: Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increased prevalence of synchronous proximal neoplasia. Two percent to 5% of patients undergoing screening colonoscopy may have isolated advanced proximal neoplasia. Even more patients may have isolated nonadvanced proximal neoplasia.     

Total Colonoscopy in Patients with Polyps in the Proctosigmoid Region

Abstract: We conducted a prospective study of the general population in Taiwan to determine how many patients with polyps in the proctosigmoid region would have synchronous polyps in the proximal colon. The pathology and the number of proctosigmoid polyps as well as the benefits of subsequent colonoscopy were taken into account. Proctosigmoid polyps were identified in 261 of 2746 asymptomatic patients by 60 cm sigmoidoscopy, yeilding a 9.5% (male: 11.0%; female: 5.0%) prevalence rate. Subsequent total colonoscopy combined with polypectomy was completed in 205 patients (152 males; 53 females) eligible for analysis. In all, 353 polyps were removed for pathological verification at colonoscopy. The mean size of adenomatous polyps was 6.2 mm and that of hyperplastic polyps 3.2mm (p<0.05). Five mucosal cancers as well as one submucosal cancer were identified, and one of the mucosal cancers was beyond the range of the prior 60 cm sigmoidoscopy. Of these 205 patients, 63 (31%) were found to have at least one proximal polyp. The prevalences of synchronous proximal colon polyps were 23%, 42% and 77% for the 1-polyp, 2-polyp and β2-polyp groups in the proctosigmoid region, respectively. When the pathology of the proctosigmoid polyps was taken into account, it was found that 42% of patients with adenomatous polyps in the proctosigmoid region had proximal polyps, compared with 10% of those with distal hyperplastic polyps and 8% of those with other findings (p<0.05). The present study suggests that all polyps, of all sizes, found at sigmoidoscopy merit pathological verification. Furthermore, colonoscopy should be reserved for patients proved to have adenomatous or multiple polyps in the proctosigmoid region.     

What does sigmoidoscopy really miss?

The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. Lewis et al. performed a systematic review and meta-analysis of screening colonoscopy studies. Published studies through July 31, 2000 of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. The authors generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia. With the sigmoid–descending colon junction used to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [Cl] = 1.42–4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio = 2.36; 95% CI = 1.30–4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio = 1.44; 95% CI = 0.79–6.62). The prevalence of isolated advanced proximal neoplasia in the three studies was 2%, 3%, and 5%, respectively. When the sigmoid–descending colon junction is used to identify the beginning of the distal colon, this yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI = 13.6%–19.1%). Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increasing prevalence of synchronous proximal neoplasia. From 2% to 5% of patients undergoing screening colonoscopy might have isolated advanced proximal neoplasia.     

The Sentinel Hyperplastic Polyp: A Marker for Synchronous Neoplasia in the Proximal Colon

We prospectively screened 129 asymptomatic subjects (mean age 64 yr) with flexible sigmoidoscopy. Colonoscopy was performed at a later date, regardless of the sigmoidoscopic result. Our intent was 1) to establish the prevalence of proximal neoplasms in patients with and without hyperplastic polyps within reach of the 60-cm sigmoidoscope and 2) to determine whether a distal (sentinel) hyperplastic polyp predicts the presence of synchronous neoplastic polyps higher up in the colon. Our results show that 15% of asymptomatic adult subjects without polyps on sigmoidoscopy have adenomas in proximal colonic segments that can be diagnosed only by colonoscopy. By comparison, proximal neoplasms were detected in 32% (p less than 0.05) and 37% (p less than 0.05) of patients when hyperplastic or adenomatous polyps, respectively, were present on the sigmoidoscopic examination. This finding suggests that a distal (sentinel) hyperplastic polyp by itself may be a marker for neoplastic polyps in proximal colonic segments. Also, the "index" adenoma and "sentinel" hyperplastic polyp may be equivalent for predicting the presence of proximal neoplasms. The observed detection rates for these polyps were both significantly higher than expected when compared to patients who did not have polyps in the distal colon or rectum. If these results can be confirmed by a larger prospective trial, then full colonoscopy for detection of proximal neoplasms may be indicated when either an index adenoma or sentinel hyperplastic polyp is detected by sigmoidoscopy.     

Criteria for the diagnosis of dysplasia by endoscopic optical coherence tomography

BACKGROUND: Endoscopic optical coherence tomography provides images of the GI mucosa and submucosa in microscopic detail. It is unknown whether endoscopic optical coherence tomography can reliably detect dysplasia. Colon polyps were used as a model to determine whether dysplasia in GI tissue has characteristic optical coherence tomography imaging features. METHODS: Endoscopic optical coherence tomography images of colon polyps and normal colon tissue were obtained at colonoscopy. In real time, endoscopists compared tissue organization and light scattering for polyps and normal mucosa with endoscopic optical coherence tomography. Imaged polyps were removed and evaluated histopathologically. Organization and light scattering, as assessed by endoscopic optical coherence tomography at colonoscopy, were compared for adenomas versus hyperplastic polyps. A computer program also quantified and compared the degree of light scattering for hyperplastic polyps and adenomas. RESULTS: A total of 44 polyps were imaged in 24 patients (30 adenomas, 14 hyperplastic polyps). Endoscopic optical coherence tomography images of adenomas had significantly less structure (p = 0.0005) and scattered light to a lesser degree than hyperplastic polyps (p = 0.0007). Hyperplastic polyps were significantly closer in organization (p = 0.0003) and light scattering (p = 0.0006) to normal mucosa as compared with adenomas. By digital image analysis, the light-scattering property of hyperplastic polyps was closer to normal mucosa compared with adenomas (14.86 vs. 45.81; p = 0.0001). CONCLUSIONS: Real-time endoscopic optical coherence tomography imaging differentiated adenomas, hyperplastic polyps, and normal colon tissue. By using the colon adenoma as a model, the endoscopic optical coherence tomography characteristics of dysplasia are loss of tissue organization and reduced light scattering.     

Screening for Colon Malignancy with Colonoscopy

Screening of asymptomatic individuals for colon malignancy has been advocated for the past 20 yr in the hopes of reducing colon cancer mortality. Although sigmoidoscopy is an important element of current screening recommendations, the sensitivity of this test in asymptomatic subjects has never been studied. The purpose of this study was to determine the prevalence and location of polyps and cancers in an asymptomatic population by performing full colonoscopy. We wished to assess the sensitivity of screening flexible sigmoidoscopy to 60 cm by determining how many patients with adenomas or cancer had "index" adenomatous polyps in the distal 60 cm. One hundred five healthy male outpatients, over 50 yr old, with negative examinations for occult blood in stools and no prior history of colon pathology, had full colonoscopy. Careful examination of the distal 60 cm was performed, followed by a full colon examination to the cecum. Forty-three patients (41%) had adenomatous polyps, and only 19 of these patients had an index adenomatous polyp in the distal 60 cm. Therefore, the sensitivity of sigmoidoscopy was 44%. The prevalence of adenomas increased with age. Patients were assigned to one of three groups based on the findings in the distal 60 cm. Group 1 (n = 65) had no polyps in the distal 60 cm, but 18 of these patients (28%) had adenomatous polyps in the proximal colon. Among 21 patients with only hyperplastic polyps in the distal 60 cm (group 2), six patients (29%) had proximal adenomas. In group 3, eight of 19 patients (42%) with adenomas in the distal 60 cm also had proximal adenomatous polyps. We conclude that adenomatous polyps are common in asymptomatic men who have negative tests for fecal occult blood. Sigmoidoscopy to 60 cm had a sensitivity of only 44% in this patient population, suggesting that this is an insensitive test for the detection of patients with adenomatous polyps.     

Is the distal hyperplastic polyp a marker for proximal neoplasia?

CONTEXT: The current literature is unclear about the association between distal hyperplastic polyps and synchronous neoplasia (adenomatous polyps and cancer) in the proximal colon. OBJECTIVE: To estimate the prevalence of proximal neoplasia associated with distal hyperplastic polyps. DATA SOURCES: Database searches (medline and embase from 1966 to 2001) and manual search of the bibliographies of included and excluded studies, case reports, editorials, review articles, and textbooks of Gastroenterology. STUDY SELECTION: Studies describing the prevalence of proximal neoplasia in persons with distal hyperplastic polyps. DATA EXTRACTION: Demographics, clinical variables, study design, and prevalence of proximal neoplasia associated with various distal colorectal findings. DATA SYNTHESIS: Of 18 included studies, 12 involved asymptomatic individuals in which the pooled absolute risk of any proximal neoplasia associated with distal hyperplastic polyps was 25% (95% confidence interval [95% CI], 21% to 29%). In 4 studies where colonoscopy was performed irrespective of distal findings, the absolute risk was 21% (95% CI, 14% to 28%). The relative risk of finding any proximal neoplasia in persons with distal hyperplastic polyps was 1.3 (95% CI, 0.9 to 1.8) compared to those with no distal polyps. Among 6 studies of patients with symptoms or risk factors for neoplasia, the absolute risk of proximal neoplasia was 35% (95% CI, 32% to 39%) in persons with distal hyperplastic polyps. In 2 studies of screening colonoscopy, advanced proximal neoplasia (cancer, or a polyp with villous histology or severe dysplasia, or a tubular adenoma >/=1 cm) was present in 4% to 5% of persons with distal hyperplastic polyps, which was 1.5 to 2.6 times greater than in those with no distal polyps. CONCLUSIONS: In asymptomatic persons, a distal hyperplastic polyp is associated with a 21% to 25% risk for any proximal neoplasia and a 4% to 5% risk of advanced proximal neoplasia, and may justify examination of the proximal colon. Further study is needed to determine the risk of advanced proximal neoplasia associated with size and number of distal hyperplastic polyps.     

Diagnostic potential of near-infrared Raman spectroscopy in the colon: differentiating adenomatous from hyperplastic polyps

BACKGROUND: Near-infrared Raman spectroscopy is a promising optical technique for GI tissue diagnosis. This study assessed the diagnostic potential of near-infrared Raman spectroscopy in the colon by evaluating its ability to distinguish between adenomatous and hyperplastic polyps. METHODS: Ex vivo and in vivo Raman spectra of colon polyps were collected by using a custom-built, fiber-optic, near-infrared Raman spectroscopic system. Multivariate statistical techniques, including principal component analysis and linear discriminant analysis, were used to develop diagnostic algorithms for classifying colon polyps based on their spectral characteristics. With the number of samples available, spectral classification of polyps was tested by using a leave-one-out, cross-validation method. RESULTS: Fifty-four ex vivo Raman spectra were analyzed (20 hyperplastic, 34 adenomatous). The spectral-based diagnostic algorithms identified adenomatous polyps with 91% sensitivity, 95% specificity, and 93% accuracy. In vivo, adenomas (n = 10) were distinguished from hyperplastic polyps (n = 9) with 100% sensitivity, 89% specificity, and 95% accuracy. CONCLUSIONS: Near-infrared Raman spectroscopy differentiated adenomatous from hyperplastic polyps with high diagnostic accuracy. To our knowledge, this is the first demonstration of the potential of near-infrared Raman spectroscopy for differentiation of colonic polyps during GI endoscopy.     

Multiple Large Hyperplastic Polyps of the Colon Coincident with Adenocarcinoma

Diminutive hyperplastic polyps are the most common non-neoplastic lesions of the colon. Typically, they are small (<0.5 cm) sessile lesions, lack cellular atypia, and are found predominantly in the rectosigmoid region of the colon. Multiple large hyperplastic polyps (>1 cm) are rare. Although the relationship between diminutive hyperplastic polyps and adenomatous polyps or carcinoma is controversial, even less data are available on the significance of large hyperplastic polyps. We report the case of a 56-yr-old man who was seen because of fatigue, anemia, and Hemoccult-positive stool. On air contrast barium enema study and colonoscopy, multiple polyps that were similar in appearance were found distributed symmetrically throughout the colon. However, histologic examination revealed 16 hyperplastic polyps 1–2 cm in size, multiple diminutive hyperplastic polyps, one adenomatous polyp, and one adenomatous polyp containing well-differentiated adenocarcinoma. Because multiple large hyperplastic polyps are rare, we suspect this entity may be distinct from diminutive hyperplastic polyps. In our patient, large hyperplastic polyps were distributed symmetrically throughout the colon and were associated with a synchronous carcinoma. Because large hyperplastic polyps may be coincident with adenomatous polyps and carcinoma of the colon, we recommend that patients found to have large hyperplastic polyps undergo removal of all polyps for histologic study.     

The role of colonoscopy and flexible sigmoidoscopy in screening for Colorectal Carcinoma

Six hundred thirty-two patients were referred to the Colorectal Clinic from February 1983 to February 1986 for screening with the Pentax 65 cm flexible sigmoidoscope. Forty-nine of these patients (8 percent) had adenomatous polyps. There were 27 males and 22 females. The mean distance examined by the 65 cm flexible sigmoidoscope was 55 cm. Five patients were excluded from analysis, leaving 44 patients who underwent colonoscopy to the cecum. At the time of colonoscopy, 15 of the 44 patients (34 percent) had one or more adenomatous polyps beyond reach of the 65 cm flexible sigmoidoscope. The remaining 29 patients who underwent colonoscopy had no polyps beyond reach of the 65 cm flexible sigmoidoscope. Thirty adenomatous polyps, one invasive carcinoma of the ascending colon, and one hyperplastic polyp were found in these 15 patients. In summary, 34 percent of patients found to have adenomatous polyps within reach of the 65 cm flexible sigmoidoscope harbored one or more adenomatous polyps in the proximal colon at the time of colonoscopy. A positive 65 cm flexible sigmoidoscope examination requires colonoscopy to identify and remove proximal premalignant lesions, thereby aborting the polyp-cancer sequence.     

Hyperplastic polyps seen at sigmoidoscopy are markers for additional adenomas seen at colonoscopy

Asymptomatic individuals undergoing screening flexible sigmoidoscopy were prospectively studied. Polyps were found in 185 subjects. The endoscopist recorded an opinion on the polyps' histology based on endoscopic appearance. No polyps were removed at sigmoidoscopy. All subjects with rectosigmoid polyps then underwent colonoscopy and polypectomy. Of them, 99 subjects (54%) had at least one rectosigmoid adenoma, 69 (37%) had only hyperplastic polyps, and 17 (9%) had other findings. The endoscopists' opinion of the histopathology of polyps at sigmoidoscopy was correct for 61% of the lesions. Of subjects with adenomatous rectosigmoid polyps, 29% had additional adenomas at more proximal sites. Proximal adenomas were found in 28% of patients with hyperplastic rectosigmoid polyps. Patients with rectosigmoid hyperplastic polyps had the same risk for additional proximal adenomas as patients with rectosigmoid adenomatous polyps.     

High Prevalence of Hyperplastic Colonic Polyps in Acromegalic Subjects

We evaluated the prevalence and features of colonic polyps in a population of acromegalic subjects, compared to a control group of patients with irritable bowel syndrome (IBS). Colonic polyps were found in 30 acromegalic subjects (40%) and in 10 controls (13%) (P < 0.0001). Among the acromegalic patients, polyps were of the hyperplastic type in 27 subjects (90%) and adenomatous in 3 (10%). In the control group, polyps were hyperplastic in nine subjects (90%) and adenomatous in one (10%). We also observed a significant association (P < 0.0001) between the presence of hyperplastic polyps and the older age in both the acromegalic and the control groups. There were no differences between the two groups regarding sex, site, size, or macroscopic and histological types of polyps. Acromegalic patients have a higher prevalence of colonic hyperplastic polyps than IBS subjects, while the prevalence of adenomatous polyps is similar in the two groups.     

Elastic scattering spectroscopy for the diagnosis of colonic lesions: initial results of a novel optical biopsy technique

BACKGROUND: Biopsy and polypectomy frequently are performed for lesions that carry a low risk of malignant transformation in the colon. Elastic scattering spectroscopy (ESS) is a novel optical biopsy technique that can distinguish, almost instantaneously, between normal and abnormal tissue in vivo, without the need to remove tissue. We assessed the diagnostic potential of ESS in the colon to differentiate normal colonic mucosa, chronic colitis, hyperplastic polyps, adenomatous polyps (with dysplasia), and adenocarcinoma. METHODS: ESS spectra were obtained from 138 sites in 45 patients at colonoscopy. They were then compared with conventional biopsy specimens taken from the same site, including normal colonic mucosa, hyperplastic polyps, adenomatous polyps, chronic colitis, and colon cancer. Spectral analysis was carried out with a validated computerized model that used principal component analysis followed by linear discriminant analysis. Cross validation was carried out by using 60% of the data as a "training set" and the remaining 40% of the data as a "test set." RESULTS: A total of 483 spectra were analyzed (290 normal, 19 hyperplastic, 69 adenomatous polyps, 74 chronic colitis, and 31 colorectal cancer). The sensitivity and the specificity of differentiating adenomas from hyperplastic polyps was 84% and 84%, respectively; for cancer from adenomatous polyps, 80% and 75%, respectively; for colitis from normal tissue, 77% and 82%, respectively; and for dysplastic mucosa (from polyps) from colitis, 85% and 88%, respectively. CONCLUSIONS: ESS holds promise for differentiating colonic lesions with good accuracy and, therefore, is a potentially useful tool to make an instantaneous diagnosis during colonoscopy. It could prove a valuable aid for targeting biopsies in dysplasia surveillance in inflammatory bowel disease and for deciding which small polyps should be removed.     

Small colorectal polyps

The histology of small (≤0.5 cm.) colorectal polyps removed during total colonoscopy in 303 patients was reviewed to determine their clinical significance. There were 178 male patients and 125 females, with a median age of 64 years (range, 26 to 97 years). A total of 766 polyps were treated, 60 percent being adenomatous and 22 percent hyperplastic. Hyperplastic polyps were more common in the rectum (71 percent) while adenomas were more common in the colon (63 percent). Hyperplastic polyps in the colon were associated with adenomas in 75 percent of cases and hyperplastic rectal polyps were associated with proximal adenomas in 63 percent. There were six mixed hyperplastic/adenomatous polyps. Of the 458 adenomas, 449 were tubular, eight were tubulovillous, and one was villous. Moderate dysplasia was noted in 23 (5 percent) and severe dysplasia in four (0.9 percent). There were associated large adenomas in 84 patients. Small colonic polyps are usually adenomatous and should be destroyed. Biopsy may be important if no other neoplasm has been identified. Small rectal polyps are usually hyperplastic but may be associated with proximal adenomas. Because of the uncertain significance of hyperplastic polyps they should also be treated, and are a relative indication for total colonoscopy. Read at the meeting of the American Society of Colon and Rectal Surgeons, Washington, D.C., April 5 to 10, 1987.     

Gastric polyps: a retrospective analysis of 26,000 digestive endoscopies

BACKGROUND: Gastric polyps are small gastric lesions, asymptomatic in most cases and are generally discovered inadvertently during upper digestive endoscopy. AIM: To retrospectively review the characteristics and frequency of gastric polyps, derived from the gastric mucosal epithelium in a large series of endoscopies. METHODS: One hundred and fifty three patients in a series of 26,000 consecutive upper digestive endoscopies done over a 5-year period, being that each patient had only one examination were analyzed and their histological and Yamada classification, as well as their location, size, histopathological findings and treatment studied. All patients had at least one gastric polyp, as confirmed by histological examination. RESULTS: The polyps were classified as hyperplastic, adenomatous and fundic gland polyps. The most of them measure less than 1 cm (hyperplastic polyps - 60,5%; adenomatous polyps - 73,6%; fundic gland polyps - 72%). Hyperplastic polyps were the most frequent and accounted for 71.3% of the cases, whereas fundic gland polyps accounted for 16.3% and adenomatous polyps for 12.4%. Hyperplastic and adenomatous polyps were primarily single, whereas fundic gland polyps tended to be multiple. A carcinoma was detected in one hyperplastic polyp (0.9%) and in two adenomatous polyps (10.5%). High grade dysplastic foci were found in four adenomatous polyps (21%). CONCLUSIONS: The digestive endoscopy is the safest and efficient method for the diagnosis of the gastric polyps, that in most of the patients does not show characteristic symptoms. The histopathological definition is not possible to the endoscopic glance being needed the pathologist's aid, once the conduct to be adopted will depend on the result of the biopsy.     

Aberrant P-cadherin expression is an early event in hyperplastic and dysplastic transformation in the colon

BACKGROUND: Colorectal adenomatous and, probably, hyperplastic polyp development requires epithelial remodelling and stratification, with loss of E-cadherin expression implicated in adenoma formation. We have shown that P-cadherin, normally expressed in stratified epithelia and placenta, is aberrantly expressed in disturbed epithelial architecture associated with colitis. AIMS: (i) To investigate the role of P-cadherin in colonic polyp formation. (ii) To ascertain whether expression of P-cadherin is independent of or correlated with expression of its associated proteins--E-cadherin, beta-catenin, and gamma-catenin. (iii) To determine if P-cadherin is functional regarding catenin binding in polyps. METHODS: Expression and localisation of cadherins (E- and P-) and their associated catenins (beta- and gamma-) were determined in aberrant crypt foci (ACF), in polyps with hyperplastic morphology (hyperplastic polyps and serrated adenomas), and in adenomatous polyps by immunohistochemistry, western blotting, and mRNA in situ hybridisation. Assessment of cadherin-catenin binding was evaluated by co-immunoprecipitation. Adenomatous polyposis coli (APC) mutation was assessed in adenomatous polyps. RESULTS: P-cadherin was expressed from ACF through to hyperplastic and adenomatous polyps. Alterations in E-cadherin and catenin expression occurred later, with variant patterns in (i) ACF, (ii) hyperplastic polyps and serrated adenomas, and (iii) adenomatous polyps. P-cadherin present in adenomas was functional with regard to catenin binding, and its expression was independent of APC mutational status. CONCLUSIONS: P-cadherin is aberrantly expressed from the earliest morphologically identifiable stage of colonocyte transformation, prior to changes in E-cadherin, catenin, and APC expression/mutation. P-cadherin expression alone does not predict tissue morphology, and such expression is independent of that of associated cadherins and catenins.     

Sex-influenced association of non-alcoholic fatty liver disease with colorectal adenomatous and hyperplastic polyps

AIM To investigate the relationship between non-alcoholic fatty liver disease(NAFLD) and colorectal adenomatous and hyperplastic polyps.METHODS A retrospective cross-sectional study was conducted on 3686 individuals undergoing health checkups(2430 males and 1256 females). All subjects underwent laboratory testing,abdominal ultrasonography,colonoscopy,and an interview to ascertain the baseline characteristics and general state of health. Multinomial logistic regression analysis was performed to examine the association between NAFLD and the prevalence of colorectal adenomatous and hyperplastic polyps.Furthermore,the relationship was analyzed in different sex groups. Subgroup analysis was performed based on number,size,and location of colorectal polyps.RESULTS The prevalence of colorectal polyps was 38.8% in males(16.2% for adenomatous polyps and 9.8% for hyperplastic polyps) and 19.3% in females(8.4% for adenomatous polyps and 3.9% for hyperplastic polyps). When adjusting for confounding variables,NAFLD was significantly associated with the prevalence of adenomatous polyps(OR = 1.28,95%CI: 1.05-1.51,P 0.05) and hyperplastic polyps(OR = 1.35,95%CI: 1.01-1.82,P 0.05). However,upon analyzing adenomatous and hyperplastic polyps in different sex groups,the significant association remained in males(OR = 1.53,95%CI: 1.18-2.00,P 0.05; OR = 1.42,95%CI: 1.04-1.95,P 0.05) but not in females(OR = 0.44,95%CI: 0.18-1.04,P 0.05; OR = 1.18,95%CI: 0.50-2.78,P 0.05). CONCLUSION NAFLD is specifically associated with an increased risk of colorectal adenomatous and hyperplastic polyps in men. However,NAFLD may not be a significant factor in the prevalence of colorectal polyps in women.     

Differential activation of ornithine decarboxylase and tyrosine kinase in the rectal mucosa of patients with hyperplastic and adenomatous polyps

Hyperplastic polyps are considered to be benign colonic lesions with almost no potential for malignant transformation. Recent reports have shown an increased association of hyperplastic polyps with adenomatous polyps and have advocated a full colonoscopy in patients who harbor hyperplastic polyps. Hyperproliferative mucosa is known to be associated with adenomatous polyps, but its relationship to hyperplastic polyps is unknown. In the present pilot study, it is determined whether a change in mucosal proliferative patterns is observed in patients who harbor only hyperplastic polyps or a history of hyperplastic polyps relative to those who harbor both hyperplastic polyps and adenomatous polyps by measuring ornithine decarboxylase and tyrosine kinase activity in macroscopically normal rectal mucosa. Fifteen patients had either adenomatous polyps proximally or harbored adenomatous polyps and hyperplastic polyps. Seven patients had hyperplastic polyps and 15 patients had a prior history of hyperplastic polyps with no polyps found during the current examination. The ornithine decarboxylase activity of the rectal mucosa with proximal adenomatous polyps or both polyp types was significantly higher than that of hyperplastic polyps, the history of hyperplastic polyps, or controls, and values for hyperplastic polyps and the history of hyperplastic polyps were similar to controls. On the other hand, tyrosine kinase activity in the rectal mucosa of patients with both or either polyp type was elevated without any significant difference between hyperplastic and adenomatous polyps. Thus, it is concluded that although increased ornithine decarboxylase activity in rectal mucosa suggests the presence of adenomatous polyps or a combination of adenomatous with hyperplastic polyps, increased tyrosine kinase activity suggests the presence of any type of polyp.