Flat adenomas in the National Polyp Study: is there increased risk for high-grade dysplasia initially or during surveillance?

BACKGROUND & AIMS: The flat adenoma may be a more aggressive pathway in colorectal carcinogenesis. Sessile adenomas from the National Polyp Study cohort were reclassified histopathologically as flat or polypoid and compared with initial and surveillance pathology. METHODS: A total of 933 sessile adenomas detected during 1980-1990 were reclassified as follows: (1) adenoma thickness (AT): < or =1.3 mm, and (2) adenoma ratio (AR): adenoma thickness <2x normal mucosa thickness. Logistic regression was used to assess whether flat adenomas had an effect on risk for high-grade dysplasia initially, and a Cox proportional hazards model assessed the risk for advanced adenomas at surveillance. RESULTS: The analysis encompassed 8401 person-years of follow-up evaluation. AT and AR measures of adenoma flatness were 95% concordant. By the AT measure, flat adenomas (n = 474) represented 27% of all baseline adenomas. Flat adenomas were found to be no more likely to exhibit high-grade dysplasia than sessile (polypoid) or pedunculated adenomas, the odds ratio for high-grade dysplasia was 1.91 (95% confidence interval [CI], 0.66-5.47; P = 0.23) for sessile (polypoid) vs. flat adenomas and 1.78 (95% CI, 0.63-5.02; P = 0.28) for pedunculated vs. flat adenomas adjusted for size, villous component, and location, and corrected for correlation of risk within an individual patient. Patients with flat adenomas at initial colonoscopy were not at greater risk for advanced adenomas at surveillance compared with those with polypoid adenomas only, the odds ratio was 0.76 (95% CI, 0.4-1.42; P = .39), adjusted for multiplicity, age, and family history of colorectal cancer. CONCLUSIONS: Flat adenomas identified in the National Polyp Study cohort at baseline were not associated with a higher risk for high-grade dysplasia initially, or for advanced adenomas at surveillance.     

Diminutive cancers of the colon and rectum: comparison between flat and polypoid cancers

A comparative study of polypoid and flat colorectal cancers less than 20 mm in size was made. A review of the characteristics of 56 polypoid cancers and 29 flat cancers treated between April 1989 and January 1996 was performed. Both groups of cancers showed similar age and location distribution. Polypoid cancers were more likely to be well differentiated (38%) than were flat cancers (17%) (P<0.05). Flat cancers were more likely to have reached the serosa (52% vs 12%; P<0.01) and also demonstrated a higher frequency of lymph node involvement (41% vs p 9%) (P<0.01) when compared to polypoid cancers. Flat colorectal cancers belong to a distinct subset which demonstrates greater biological aggressiveness than polypoid cancers of equivalent size. Accepted: 5 June 1998     

Colorectal flat neoplasia

BACKGROUND AND AIMS: An attempt has been made to evaluate the clinicopathological characteristics of flat colorectal neoplastic lesions, and analyse the factors associated with the malignancy. PATIENTS AND METHODS: A total of 115 flat neoplastic lesions, > or = 5 mm in size, diagnosed in 87 patients by colonoscopy, were investigated. RESULTS: The rectum was the most common location. Almost half (49.6%) of the flat neoplasms were small (5-10 mm), 27.8% were 11-20 mm and the remainder (22.6%) larger than 20 mm. The surface was smooth in 55.7%, granular in 20.0% and nodular in 24.3%. Histologically, the flat lesions were tubular, tubulovillous and villous adenomas in 69.6%, 20.9% and 5.2%, respectively. Five lesions (4.3%) were composed of carcinomas without adenoma. High-grade dysplasia, intramucosal carcinoma and invasive carcinoma were diagnosed in 9.6%, 7.8% and 6.1% of all flat neoplasms, respectively. Univariate analysis demonstrated that the location, size, surface pattern and histologic type of the flat lesions were factors associated with malignancy. However, in multivariate analysis, the size of the flat lesions was the only significant risk factor for malignant transformation. CONCLUSIONS: Flat neoplastic lesions of the colorectum have a relatively high rate of malignancy, and size is the most important factor associated with malignancy.     

Clinicopathologic Characteristics and Malignant Potential of Colorectal Flat Neoplasia Compared with that of Polypoid Neoplasia

Purpose Because of their potential for malignancy, flat colorectal neoplasias are a current topic of debate. This study was designed to investigate the clinicopathologic features of flat neoplasia and to compare them with those of polypoid neoplasia, as well as to identify the determinants of malignant transformation of both flat and polypoid colorectal neoplasia. Methods A prospective, cross-sectional study of 3,360 patients diagnosed with adenomas via total colonoscopy and polypectomy was performed at 11 tertiary medical centers between July 2003 and July 2004. In this study, potential risk factors for malignant transformation were analyzed. If multiple adenomas were identified, then only the adenoma with the most advanced degree of histology was recorded for the patient. Results Of a total of 3,360 neoplasias identified, we found that the incidence of flat and polypoid neoplasias were 207 (6.2 percent) and 3,153 (93.8 percent), respectively. Patients with flat neoplasias tended to be older (59.6 vs. 57.1, P < 0.01), with the neoplaisa located more frequently in the right colon than polypoid neoplasias (49.3 percent vs. 32 percent, P < 0.01). The incidence of high-grade dysplasia or cancer in flat neoplasias was similar to that of polypoid neoplasias (5.4 percent vs. 4.6 percent, P = 0.36). Multivariate analysis revealed that a size of ≥11 mm (odds ratio, 6.8; 95 percent confidence interval, 4.8–9.7) and location in the left colon (odds ratio, 1.6; 95 percent confidence interval, 1.1–2.4) were significant determinants for the malignancy potential of colonic neoplasias. Conclusions The clinicopathologic indices for the propensity of malignant transformation in colorectal neoplasias were a size ≥11 mm and location in the left colon rather than flat gross morphology.     

Malignant potential in flat elevations

Ninety-nine colonoscopically removed flat elevations were examined. They were divided into two groups: Group 1—flat elevations 1 to 5 mm in diameter (55 cases)- and Group 2—flat elevations 6 to 10 mm in diameter (44 cases). Group 2 had a higher percentage of adenomas (86.4 percent) than Group 1 (67.3 percent). In adenoma cases (flat adenomas), Group 2 tended to show a higher degree of dysplasia. The rates of mild and moderate dysplasia were 83.8 percent and 16.2 percent in Group 1 vs. 1.70 percent and 13.2 percent in Group 2, respectively. Group 2 contained six cases (15.8 percent) of intramucosal carcinoma (severe dysplasia), while there were no cancer cases in Group 1. Both malignancy rate and degree of dysplasia were size dependent; the larger the lesion the more severe the dysplasia. Our study also revealed that small flat elevations tend to contain higher numbers of nonneoplastic lesions than do larger lesions. Increased detection of nonneoplastic lesions seems to have contributed to an overall decline in the malignancy rate of flat elevations in recent reports.     

Cell Kinetics,p53 and bcl-2 Expression,and c-Ki-ras Mutations in Flat-Elevated Tubulovillous Adenomas and Adenocarcinomas of the Colorectum: Comparison with Polypoid Lesions

Background: Flat(-elevated) tubulovillous adenomas and adenocarcinomas of the colorectum constitute a specific type of neoplasm with superficial spreading growth. To establish their characteristics, a comparative investigation of a series of tumors was performed. Methods: A total of 56 flat tubulovillous tumors (39 adenomas, 17 invasive carcinomas) and 154 polypoid tubular or villous tumors (77 adenomas, 77 invasive carcinomas) were comparatively assessed for cell kinetics and molecular alterations. Results: Ki-67 labeling and p53 expression for both types of tumors increased along with degree of dysplasia or invasion, whereas bcl-2 expression showed an inverse decrease. However, apoptotic activity was invariably low in the flat tubulovillous tumors, as compared with the polypoid tumors, in which increase was apparent with tumor progression. The flat tubulovillous tumors also showed a higher frequency of c-Ki-ras mutations (92.9%) than the polypoid tubular tumors (40.0%). Conclusions: The flat tubulovillous tumor can be considered a distinct entity, with characteristics different from the polypoid counterpart.     

Cell kinetics, p53 and bcl-2 expression, and c-Ki-ras mutations in flat-elevated tubulovillous adenomas and adenocarcinomas of the colorectum: comparison with polypoid lesions.

BACKGROUND: Flat(-elevated) tubulovillous adenomas and adenocarcinomas of the colorectum constitute a specific type of neoplasm with superficial spreading growth. To establish their characteristics, a comparative investigation of a series of tumors was performed. METHODS: A total of 56 flat tubulovillous tumors (39 adenomas, 17 invasive carcinomas) and 154 polypoid tubular or villous tumors (77 adenomas, 77 invasive carcinomas) were comparatively assessed for cell kinetics and molecular alterations. RESULTS: Ki-67 labeling and p53 expression for both types of tumors increased along with degree of dysplasia or invasion, whereas bcl-2 expression showed an inverse decrease. However, apoptotic activity was invariably low in the flat tubulovillous tumors, as compared with the polypoid tumors, in which increase was apparent with tumor progression. The flat tubulovillous tumors also showed a higher frequency of c-Ki-ras mutations (92.9%) than the polypoid tubular tumors (40.0%). CONCLUSIONS: The flat tubulovillous tumor can be considered a distinct entity, with characteristics different from the polypoid counterpart.     

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

Abstract

Objectives: Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

Methods: We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

Results: Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r?=?0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist’s level of proficiency, number of colonoscopy operators and withdrawal time.

Conclusions: The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of >?60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6?min.     

Risk of advanced metachronous colorectal adenoma during long-term follow-up

Background  According to the adenoma–carcinoma concept, all colorectal adenomas are to be removed and all patients have to undergo regular surveillance examinations. But there is still shortage on information on the long-term results of follow-up colonoscopy after polypectomy. Methods  Between 1978 and 2003, more than 20,000 polyps were prospectively documented at the Erlangen Registry of Colorectal Polyps. A total of 1,091 patients undergoing periodic surveillance examinations are studied for differences between initial and metachronous lesions of the colorectum. Statistical analysis using χ ²-testing of adenoma characteristics found in four subsequent recurrence periods and calculation of the relative risk (RR) for the development of metachronous adenomas of advanced pathology was performed. Results  In comparison with the initial findings, metachronous adenomas are, in general, significantly smaller ones (p < 0.00001), more frequently tubular lesions (p < 0.00001) and bearing less often high-grade dysplasia (p < 0.00001). Adenomas of advanced pathology were significantly less often found during follow-up than at baseline examination (p < 0.0001). These differences are found between the initial and four subsequent generations of metachronous adenomas. Patients with adenomas of advanced pathology at baseline have a significantly higher risk for metachronous adenomas of advanced pathology (RR 1.51; 95%CI 1.04–1.93) at the first recurrence. Conclusions  Metachronous adenomas show uniform characteristics of being small tubular lesions rarely bearing high-grade dysplasia. Thus, regular surveillance examinations can provide sufficient colorectal carcinoma prevention.     

大肠平坦型腺瘤与隆起型腺瘤的临床特征比较

目的 探讨大肠平坦型腺瘤的发病情况,比较平坦型腺瘤与隆起型腺瘤的临床特征和镜下特点。方法设定一个时间段选择我院连续行结肠镜检查的患者,经肠镜下切除的并经病理证实为腺瘤的所有病变,收集完整的一般临床资料,根据镜下肉眼形态分为平坦型腺瘤和隆起型腺瘤,计算平坦型腺瘤在结肠镜检查人群中的检出率,应用构成比计算平坦型腺瘤占检出腺瘤的比例,比较平坦型腺瘤和隆起型腺瘤的临床特征和镜下特点,包括患者性别、年龄、病变大小和部位。结果结肠镜检查共10319例,符合纳入标准的共468例患者,550枚息肉,其中检出30例31枚息肉为平坦型腺瘤,438例519枚息肉为隆起型腺瘤,平坦型腺瘤在结肠镜检查人群中的检出率为0．29％,占检出腺瘤的6．41％;平坦型腺瘤和隆起型腺瘤的性别、年龄、大小和单发腺瘤／多发腺瘤的比率差异均无显著性;平坦型腺瘤有41．94％位于右半结肠,而隆起型腺瘤仅24．47％,差异有盟著性。结论平坦型腺瘤在国内并非罕见,平坦型腺瘤较隆起型腺瘤倾向发生于右半结肠,提示全大肠镜检查更有利于检出平坦型腺瘤。     

Agreement in interpreting villous elements and dysplasia in adenomas less than one centimetre in size

Background

Villous elements and dysplasia grade in small adenomas are used in many countries to guide post-polypectomy colonoscopy intervals.

Aims

Measure agreement in interpretation of villous elements and dysplasia in small adenomas.

Methods

Consecutive endoscopically resected adenomas <10 mm in size (203 adenomas less than 6 mm and 149 adenomas 6–9 mm in size) were reviewed by 3 expert gastrointestinal pathologists. Interpretations were compared to routine clinical pathology readings at our institution and to each other.

Results

All pathologists used the same definitions for villous and tubular histology. The overall kappas for villous elements in <6 mm and 6–9 mm adenomas were 0.29 and 0.26, respectively. Interpretation of dysplasia grade had kappas of 0.02 and 0.09 for adenomas <6 mm and 6–9 mm, respectively. Two expert pathologists who used cytologic criteria had much higher fractions of high grade dysplasia compared to the third expert and the pathologists at our centre, who relied on architectural criteria.

Conclusions

Villous elements and dysplasia grade in small adenomas are problematic as determinants of post-polypectomy surveillance intervals. Uniform pathologic criteria for dysplasia grade are needed.     

Comparison of malignant potential between serrated adenomas and traditional adenomas

BACKGROUND: Serrated adenoma is a discrete colorectal epithelial neoplastic lesion that can evolve into colorectal cancer. However, the degree of malignant potential has not been firmly established as yet. The purpose of the present paper was to compare the malignant potential and clinicopathological features between serrated and traditional adenomas. METHODS: A total of 124 serrated adenomas from 116 patients were assessed, and 419 traditional adenomas from 200 were randomly selected. The combination of nuclear dysplasia and serration of > or =20% of crypts was regarded as serrated adenoma. The clinicopathological features of serrated and traditional adenomas were compared, and multivariate analysis performed to confirm whether the malignant potential of serrated adenoma was similar to that of traditional adenoma. RESULTS: The differences in age, sex, total number of adenomas, and synchronous lesions including adenoma with high-grade dysplasia and carcinoma between subjects with and without serrated adenoma were not significant. Serrated adenomas were more frequently located in the rectum and sigmoid colon (P < 0.001), and the average size of serrated adenomas was greater than that of traditional adenomas (P < 0.05). The incidence of malignant lesions including high-grade dysplasia and carcinoma in serrated adenomas was found to be lower than in traditional adenomas (3.2% vs 9.3%, P < 0.05). In the multivariate analysis, adenoma type and polyp size constituted the risk factors for the incidence of high-grade dysplasia and carcinoma. CONCLUSIONS: Serrated adenoma is a premalignant lesion, but it has a lower potential for the development of malignancy than traditional adenomas.     

Risk of cancer in small and diminutive colorectal polyps

The prevalence of cancer in small and diminutive polyps is relevant to “resect and discard” and CT colonography reporting recommendations.We evaluated a prospectively collected colonoscopy polyp database to identify polyps <10 mm and those with cancer or advanced histology (high-grade dysplasia or villous elements).Of 32,790 colonoscopies, 15,558 colonoscopies detected 42,630 polyps <10 mm in size. A total of 4790 lesions were excluded as they were not conventional adenomas or serrated class lesions.There were 23,524 conventional adenomas <10 mm of which 22,952 were tubular adenomas. There were 14,316 serrated class lesions of which 13,589 were hyperplastic polyps and the remainder were sessile serrated polyps. Of all conventional adenomas, 96 had high-grade dysplasia including 0.3% of adenomas ≤5 mm in size and 0.8% of adenomas 6–9 mm in size. Of all conventional adenomas, 2.1% of those ≤5 mm in size and 5.6% of those 6–9 mm in size were advanced. Among 36,107 polyps ≤5 mm in size and 6523 polyps 6–9 mm in size, there were no cancers.These results support the safety of resect and discard as well as current CT colonography reporting recommendations for small and diminutive polyps.     

Quantitative analysis of numerical chromosome aberrations in various morphological types of colorectal carcinomas

Quantitative analysis by fluorescence in situ hybridization (FISH) on thin paraffin-embedded tissue sections, using specific probes for chromosomes 11, 17, and 18 was employed in various morphological types of early and advanced colorectal cancer to clarify tumor cytogenetics. The chromosome index (CI) was calculated as a quantitative measure of the chromosome copy number. Compared with the CI of normal epithelium, the CI of chromosome 11 in villous components of adenomas or polypoid early cancers was decreased, while the CI in flat type or advanced colorectal cancers, conversely, was increased (P<0.05). The CI of chromosome 17 in villous components of adenomas and all cancers was higher than that of normal epithelium (P<0.05), but the differences were not significant. In protruding advanced cancers, the CI of chromosome 18 was significantly decreased (P<0.01) compared to the CI of normal epithelium. There was no significant chromosomal heterogeneity between the superficial and the deepest layer in each cancer. In mucosa adjacent to sessile and flat type cancers, the CI of chromosome 17 was significantly higher than the CI in normal epithelium or adenomas (P<0.05). These results suggest that numerical chromosome aberrations are associated with the histological type of adenoma and the morphological diversity of cancer in the colorectum, and that chromosome 17 abnormality occurs in mucosa adjacent to sessile and flat cancers.     

Ki-ras proto-oncogene mutations in sporadic colorectal adenomas: relationship to histologic and clinical characteristics

BACXKGROUND & AIMS: The goal of this study was to examine the relationship between Ki-ras mutations in colorectal adenomas and characteristics of both the subject (age, gender, and family/personal history of colonic neoplasia) and the adenoma (multiplicity, size, location, and histologic features). METHODS: Ki-ras mutations were detected by direct sequencing in 738 adenomatous polyps removed at baseline from 639 participants in a nutritional trial of adenoma recurrence. RESULTS: Ki-ras mutations were detected in 17.2% of the adenomas. Ki-ras mutations were unrelated to gender, family, or personal history of colonic neoplasia, location within the colorectum, or adenoma multiplicity, but were more common in older subjects (P = 0.01 for trend), in larger adenomas (P < 0.0001 for trend), in adenomas with villous histology (odds ratio [OR], 3.2; 95% confidence interval [CI], 2.1-4.9 vs. tubular), and in adenomas with high-grade dysplasia (32.0% vs. 13.6%; OR, 3.0; 95% CI, 1.9-4.6 vs. low-grade dysplasia). Multivariate analysis showed Ki-ras mutations to be independently associated with subject age (P = 0.01 for trend), tubulovillous/villous histology (OR, 2.3; 95% CI, 1.5-3.7), and high-grade dysplasia (OR, 1.9; 95% CI, 1.2-3.1). Adenoma size was not independently related to Ki-ras mutation. CONCLUSIONS: Ki-ras mutations are associated with the histologic features of adenoma progression (villous histology and high-grade dysplasia) rather than with adenoma growth.     

Prevalence and Malignant Potential of Colorectal Polyps in Asymptomatic, Average-Risk Men

Screening colonoscopy was performed on 119 asymptomatic elderly men with no other risk factors for colonic neoplasms. Ninety adenomas were detected in 49 (41%) subjects. Mean adenoma size was 6.5 mm, with 83 (92%) less than or equal to 10 mm. Forty-nine (54%) adenomas were located proximal to the splenic flexure, and 17 (19%) were classified as tubulovillous or villous. Moderate- to high-grade dysplasia was found in 29 (32%) adenomas and was associated with larger size (p less than 0.0001) and villous architecture (p = 0.0038). Two subjects harbored adenomas with invasive cancer. Seventy-one hyperplastic polyps were found in 40 (34%) subjects. The mean size of hyperplastic polyps was 3.4 mm, and 64 (90%) were located in the left colon. We conclude that, in this population, adenomas are common lesions that are frequently small. However, substantial proportions of these adenomas may be at risk for malignant degeneration due to the presence of villous architecture and higher grades of dysplasia. Because adenomas and hyperplastic polyps are endoscopically indistinguishable, all polyps found at endoscopy should be removed or ablated.     

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.     

Prevalence and distinctive biologic features of flat colorectal adenomas in a North American population

BACKGROUND & AIMS: To assess the prevalence of flat and depressed (F&D) colorectal adenomas in the United States, we performed a prospective study of 211 American patients. METHODS: Dye-assisted colonoscopy was performed in the presence of both an American and a Japanese investigator. RESULTS: F&D lesions were found in 22.7% of patients, and these were more likely to be adenomatous than polypoid lesions (82% vs. 67%; P = 0.03) and contained more invasive cancer (4.5% vs. 0%; P = 0.04), which also appeared to be at a disproportionately advanced stage. The average size of all F&D advanced lesions (high-grade dysplasia and cancer) was significantly smaller than comparable polypoid lesions (10.75 +/- 2.7 mm vs. 20 +/- 2.9 mm; P < 0.05). F&D adenomas showed significantly stronger fragile histidine triad (FHIT) expression and lower p53 reactivity than similarly sized polypoid adenomas, whereas proliferative and apoptotic indices were similar in both groups. CONCLUSIONS: We conclude that there is a significant prevalence of colonic F&D colorectal adenomas in this country and that these lesions have significantly different biologic features than polypoid lesions. The clinical and epidemiologic implications of these findings for American patients need to be addressed in further studies.     

Serum leptin, adiponectin, and resistin concentration in colorectal adenoma and carcinoma (CC) patients

Introduction  Leptin, adiponectin, and resistin are the proteins secreted by adipocytes, which affects the metabolism. While the role of leptin in colon carcinogenesis is documented, the effect of adiponectin and resistin remains unclear. It has been indicated that while leptin may potentiate the cancer cells growth, adiponectin and resistin may act oppositely. Aim  The aim of this study is to determine the concentration of leptin, adiponectin, and resistin in patients with adenomatous polyps and colorectal cancer. Methods  The serum concentration investigated adipohormones had been measured with ELISA in 37 patients with colorectal adenomas, 36 with colorectal cancer (CC) and in 25 controls with no colorectal pathology. Endoscopically removed polyps and CC biopsies had been evaluated with histopathology. Mean BMI value was calculated for all patients. Results  Among 37 adenomas, 25 revealed high-grade dysplasia (HGD) and 12 low-grade dysplasia (LGD). All cases of CC were adenocarcinomas. No difference in the level of investigated adipohormones in serum between patients with HGD and LGD polyps was observed. The serum concentration of leptin and adiponectin in CC patients was lower than in patients with adenomas (p < 0.05; p < 0.05, respectively) as well as in controls (p < 0.01; p < 0.05, respectively). The concentration of resistin in CC was not significantly different in the adenoma group (p > 0.05) but higher than in controls (p < 0.05). There was a correlation between adiponectin and leptin serum concentration (r = 0.61). Conclusion  We conclude that serum concentration of adiponectin and resistin may play an important role in colon carcinogenesis. We also assume that leptin may possibly have the prognostic value useful in clinical practice and its concentration is independent of BMI value.     

The expression of CD66a and possible roles in colorectal adenoma and adenocarcinoma

Background The aim of our study was to analyze the expression and possible role of CD66a in colorectal adenoma and adenocarcinoma and the relationship between its expression and pre-operation serum carcinoembryonic antigen (CEA) level and tumor stage in patients with colorectal adenocarcinomas. Methods Paraffin-embedded sections from 184 patients including 42 colorectal adenomas with low-grade dysplasia, 43 adenomas with high-grade dysplasia, and 99 adenocarcinomas were collected for this study. Immunohistochemical analysis was performed, and the expression and the location of CD66a were evaluated and were correlated with β-catenin nuclear expression. Results The expression of CD66a was found not only in the apical membrane of neoplastic glands but also in secretion within the lumen of the neoplastic glands including adenomas and adenocarcinomas. Expressions of secreted CD66a were of higher level in adenocarcinoma than in adenoma with high-grade dysplasia and adenoma with low-grade dysplasia (p < 0.0001). High expression of secreted CD66a was also associated with tumor stage, invasion, and pre-operation serum CEA level of patients with colorectal adenocarcinoma. Conclusions This study implied that CD66a can function both as an epithelial cell adhesion protein or alternatively as secreted CD66a. In addition, a high expression of CD66a was significantly correlated with tumor invasion, stage, and pre-operation serum CEA level.