结肠镜下老年人大肠息肉临床特点分析

目前认为60％～80％大肠癌起源于大肠腺瘤,即“腺瘤-腺癌演变说”.随着年龄的增长,息肉的检出率呈增加趋势,且大肠息肉与肠癌关系密切.分析大肠息肉的临床特点、内镜下表现及病理类型,对于大肠息肉的诊治、大肠息肉癌变的早期防治具有重要的临床意义.收集我科近2年来结肠镜下发现的118例老年人大肠息肉的临床资料,并与146例中青年患者比较.现将结果报道如下.     

老年人大肠息肉与大肠癌

为了解老年人大肠息肉和大肠癌的临床特点，更好地预防老年人大肠肿瘤的发生和早期诊断大肠癌，对２４８例老年人大肠息肉和大肠癌的临床及病理作一回顾性分析，结果老年人大肠息肉和大肠癌的检出率分别为３３．３％和２３．３％，并有以下特点：（１）大肠息肉和大肠癌是老年人便血的主要原因，炎性息肉，腺瘤性息肉及大肠癌三者的便血率依次增高；（２）息肉检出率显著高于普通人群息肉检出率，且腺瘤性息肉占７３．８％（３）多发     

大肠癌及各类大肠息肉流式细胞DNA定量研究

大肠息肉是一种常见的良性肿瘤,其中腺瘤性息肉与大肠癌的发生有密切关系。我们应用流式细胞计对不同病理类型的大肠息肉组织细胞ＤＮＡ进行定量分析,以探讨各类息肉、尤其是腺瘤性息肉,伴轻度及重度异型增生者与大肠癌组织细胞ＤＮＡ含量的变化规律及其生物学特性,为临床正确处理各类型息肉提供理论依据。一、材料和方法1材料来源:65例标本均为内镜下活检组织,其中正常大肠黏膜6例,炎性息肉10例,增生性息肉7例,腺瘤性息肉10例,腺瘤性息肉伴轻度异型增生10例,伴中重度异型增生12例,大肠癌10例。2方法:标本经10%甲醛溶液固定,石蜡包裹切片,常…     

大肠息肉181例临床分析

大肠息肉是一种常见病，且大多为腺瘤样息肉，腺瘤属癌前病变己被公认。大肠癌多数由息肉恶变而来，研究大肠息肉的分布、大小、形态和临床病理特征，对早期发现并摘除息肉及降低肠癌发病率有重要意义。以下是对我院近3年肠镜发现的181例大肠息肉的分析。     

大肠锯齿状病变的分子改变

大肠癌是世界范围内死亡率居第三位的恶性肿瘤，大肠息肉一直被认为是其主要的癌前疾病。传统观点将大肠息肉分为腺瘤、增生性息肉、错构瘤性息肉以及炎性息肉，并认为近80％散发性大肠癌是由腺瘤引起的，而增生性息肉，一直以来认为其不会引起恶变。     

大肠腺癌与大肠癌的关系

本组有168例大肠腺瘤,癌变18例,癌变率为10.7％。本文将临床与病理结合起来,并联系文献分析大肠腺瘤与大肠癌之间的内在关系,以寻求一条早期诊断及治疗大肠癌的途径。 1 对象和方法 本文调查了我院近10年来行结肠镜检查的2051例患者,发现癌变18例。癌变病例中,男6例,女12例,年龄30—67岁,左半结肠17例,右半结肠(横结肠)1例。瘤体大小:>2cm 16例,<2cm 3例。将2051病例分为腺瘤性息肉组168例和非腺瘤性息肉组264例。根据年龄影响腺瘤的非典型增生率,又将腺瘤性息肉组病例分为35岁以下及     

代谢综合征与大肠肿瘤的关系

我国大肠癌的发病率逐年升高，在城市地区已成为发病率最高的恶性肿瘤之一。2001年对北京市普通人群一项大肠癌筛检工作中，28．35％患者检出大肠息肉，其中腺瘤性息肉占67％，反映北京城区人群中大肠腺瘤的发病率相当高，这也是大肠癌在北京地区高发的原因。流行病学资料、临床、动物实验研究结果均表明，大肠腺瘤、大肠癌发病原因与环境因素密不可分，如肥胖、缺乏锻炼、低纤维素饮食、糖尿病、高脂血症等，上述危险因素均与代谢综合征密切相关。虽然代谢综合征与大肠肿瘤发病相关已受到注意，但远未受到重视，相关研究文献远少于大肠肿瘤其他方面的研究。以下对有关研究进行综述。     

bcl-2、bag-1与老年大肠癌患者的关系

<正>大肠腺瘤属癌前病变,与大肠癌密切相关〔1〕。大肠癌发病与饮食结构、肠道慢性炎症、遗传、大肠腺瘤等因素有关〔2〕。本研究观察老年大肠癌、大肠腺瘤患者组织中bcl-2、bag-1的表达及其在大肠癌的转移、发展中的相互关系。1资料与方法1.1研究对象2008²013年我院手术治疗并经术后病理证实的35例大肠腺瘤标本,50例大肠癌标本。另外,选取30例大肠癌或大肠腺瘤手术患者的正常大肠黏膜标本作为对照组。     

丁杏芬等研究发现大肠腺瘤是癌前病变

“直肠肛管腺瘤、息肉患者虽经摘除处理,但其复发率和新发率远较一般人高,对这些患者进行定期复查观察,对于防治大肠腺瘤、息肉及大肠癌具有重要意义”。这是浙江省海宁市肿瘤防治研究所丁杏芬等在完成“影响大肠息肉复发及癌变因素的前瞻性研究”后得出的结论。 海宁市是全国大肠癌防治现场点,对大肠癌的全面观察已有20~ a的历史。海宁市肿瘤防治研究所丁杏芬等对全市在1977年和1980年两次普查中查出的4072例直肠肛管腺瘤、息肉进行了长达20a的定期复查和追踪观察,其中对第一批2815例高危人群     

大肠腺瘤性息肉癌变因素的探讨——附245例分析

本文回顾性的总结分析了我院245例大肠腺瘤性息肉的内镜诊断和病理特点，旨在探讨大肠腺瘤癌变过程的相关因素，以提高大肠癌的早期诊断率。临床资料我院1978年～1996年间进行肠镜检查6807例，检出息肉629例，检出率9．24％。其中腺瘤性息肉245例，检出率3．60％。245例腺癌性息肉中，男167例，女78例。男女之比2．14：1。年龄8～81岁，平均44S岁。临床表现以便血或粘液血便为主，占53．88％（132例）。息肉分布：直肠102例（4。63％），乙状结肠79例（3．24％），降结肠19例（．76％），横结肠20例（．16％），升结肠及盲肠17例（．94％）…     

结直肠息肉癌变的内镜下表现、治疗及癌变因素分析

目的探讨结直肠息肉癌变的内镜下表现,分析癌变相关因素和治疗策略。方法回顾性分析经电子结肠镜检查或治疗的77例结直肠癌变息肉患者的临床、内镜及病理资料,探讨影响结直肠息肉癌变的相关因素及其内镜下治疗策略。结果77例癌变结直肠息肉中,9例伴发结肠癌。60例有临床症状,症状发生率为77．9％（60／77）。息肉癌变主要分布在乙状结肠,多发生于年龄超过60岁的老年患者,绒毛状腺瘤癌变率最高。行电子结肠镜电切法切除44例,其中完全切除38例。结论年龄〉60岁患者和乙状结肠息肉癌变发生率明显增高,选择性对属于原位癌或早期浸润癌的癌变息肉行电子结肠镜下切除是安全有效的。     

Mucin associated Tn and sialosyl-Tn antigen expression in colorectal polyps.

Sialosyl-Tn antigen and its immediate precursor, Tn antigen, are carbohydrate structures associated with the earliest steps of mucin O-linked glycosylation. Both antigens have been shown previously to be highly sensitive and specific markers of colorectal cancer. One hundred and three colorectal polyps (79 adenomatous; 24 hyperplastic) were examined for expression of Tn antigen using vicia villosa isolectin B4, and for sialosyl-Tn antigen by monoclonal antibody TKH2. Tn antigen was expressed by all of the polyps studied. Sialosyl-Tn, on the other hand was expressed weakly by a few cells in 7 of 24 (29%) hyperplastic polyps. Among the adenomatous polyps, 56% expressed sialosyl-Tn and expression correlated with larger adenoma size, greater villous component, and more severe grades of dysplasia. In individuals with two or more synchronous adenomas, the level of sialosyl-Tn expression within an adenoma was associated with the severity of cytological atypia. All the adenomas that contained a focus of invasive carcinoma expressed sialosyl-Tn. These results indicate that colorectal polyps manifest incomplete glycosylation, exposing antigens in the innermost region of mucin oligosaccharides. In addition, the correlation of sialosyl-Tn antigen expression with the adenoma-carcinoma sequence may make this a useful marker for studying malignant progression in the colon.     

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

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

Colonoscopy in asymptomatic individuals with a family history of colorectal cancer

A prevalence screening program with colonoscopy was undertaken in four kindreds manifesting the cancer family syndrome. Forty-five percent of counseled patients underwent colonoscopy, providing 42 asymptomatic individuals. Seven patients (17%) were found to have adenomatous or villous polyps; two of these were malignant and one showed epithelial atypia. Three of the seven patients with polyps had multiple lesions. Only two patients had rectosigmoid polyps. From these limited data, colonoscopy is recommended as a useful screening procedure in individuals at high risk for colorectal cancer.     

大肠息肉与大肠癌的演变关系（附494例分析）

本组息肉患者４９４例，癌变者１０１例，随着息肉的增大，其癌变率也增加。恶变息肉主要分布在直肠（５７．４％），次为乙状结肠（１９．８％）。管状腺瘤瘤体较小，恶变率较低，绒毛型腺瘤瘤体较大，恶变率较高，且呈重度不典型增生多见。单发息肉癌变率１３．１％，２－５个息肉者癌变率２４．４％，６个以上者癌变率３８．０％，腺瘤病１２例全部癌变。息肉癌变时间１至１５年。癌变术后标本病理均见癌旁组织残存良性管状腺瘤或绒毛型腺瘤成份，从组织学上证明了息肉癌变过程。     

Growth of colorectal polyps: redetection and evaluation of unresected polyps for a period of three years.

BACKGROUND, AIMS, AND PATIENTS: In a prospective follow up and intervention study of colorectal polyps, leaving all polyps less than 10 mm in situ for three years, analysis of redetection rate, growth, and new polyp formation was carried out in 116 patients undergoing annual colonoscopy. The findings in relation to growth and new polyp formation were applied to 58 subjects who received placebo. RESULTS: Redetection rate varied from 75-90% for each year, and was highest in the rectum and sigmoid colon. There was no net change in size of all polyps in the placebo group, however, polyps less than 5 mm showed a tendency to net growth, and polyps 5-9 mm a tendency to net regression in size, both for adenomas and hyperplastic polyps. This pattern was verified by computerised image analysis. Patients between 50 and 60 years showed evidence of adenoma size increase compared with the older patients, and the same was true for those with multiple adenomas (four to five) compared with those with a single adenoma. The new adenomas were significantly smaller and 71% were located in the right side of the colon. Patients with multiple adenomas had more new polyps at all the follow up examinations than patients with a single adenoma. One patient developed an invasive colorectal carcinoma, which may be evolved from a previously overlooked polyp. Two polyps, showing intramucosal carcinoma after follow up for three years, were completely removed, as judged by endoscopy and histological examination. CONCLUSIONS: The results show that follow up of unresected colorectal polyps up to 9 mm is safe. The consistency of growth retardation of medium sized polyps suggests extended intervals between the endoscopic follow up examinations, but the increased number of new polyps in the proximal colon indicates total colonoscopy as the examination of choice. The growth retardation of the medium sized polyps may partly explain the discrepancy between the prevalence of polyps and the incidence of colorectal cancer.     

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

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

Prevalence and features of colorectal lesions among Hispanics: A hospital-based study

AIM: To evaluate the prevalence and characteristics of colorectal adenoma and carcinoma in an inner city Hispanic population.METHODS: We reviewed the reports of 1628 Hispanic patients who underwent colonoscopy at Howard University from 2000 to 2010. Advanced adenoma was defined as adenoma ≥ 1 cm in size,adenomas with villous histology,high grade dysplasia and/or invasive cancer. Statistical analysis was performed using χ2 statistics and t-test.RESULTS: The median age of the patients was 54 years,64.2% were females. Polyps were observed in 489(30.0%) of patients. Adenoma prevalence was 16.8%(n = 273),advanced adenoma 2.4%(n = 39),and colorectal cancer 0.4%(n = 7). Hyperplastic polyps were seen in 6.6% of the cohort(n = 107). Adenomas predominantly exhibited a proximal colonic distribution(53.7%,n = 144); while hyperplastic polyps were mostly located in the distal colon(70%,n = 75). Among 11.7%(n = 191) patients who underwent screening colonoscopy,the prevalence of colorectal lesions was 21.4% adenoma,2.6% advanced adenoma; and 8.3% hyperplastic polyps.CONCLUSION: Our data showed low colorectal cancer prevalence among Hispanics in the Washington DC area. However,the pre-neoplastic pattern of colonic lesions in Hispanics likely points toward a shift in this population that needs to be monitored closely through large epidemiological studies.     

Total colonic polyp diameter: a marker for the risk of malignancy?

BACKGROUND/AIMS: The correlation of the risk of malignancy with the sum of the diameters of small colonic polyps is unknown, and data regarding this topic are lacking. In this study, the relationship between the sum of the diameters of the total number of colonic polyps and poor histopathologic characteristics was examined. METHODS: A total of 920 neoplastic colon polyps were evaluated in 480 patients. The "total polyp diameter" (i.e. the sum of all polyp diameters identified during colonoscopy), which was calculated in each patient by adding the diameter of each polyp to a sum, was categorized as "small" (<10mm in diameter) or "large" (> or =10mm in diameter). The polyps were further categorized by histopathologic component as "unfavorable" or "favorable" and were divided into 2 groups: group 1 (those identified as carci noma, carcinoma in situ, villous adenoma, and tubulovillous adenoma with a villous component of more than 25%) and group 2 (mixed adenomatous polyps with various degrees of hyperplastic or inflammatory components and adenomas with a tubular component of more than 75%). RESULTS: Large polyps that had a total diameter greater than or equal to 10mm tended to have poor histopathologic characteristics (p<0.05). Polyps generally tended to localize in the left portion of the colon, and malignant polyps or those at risk for malignancy in particular tended to localize in the left colon (p<0.05). CONCLUSIONS: Polypectomy is recommended for patients in whom the sum of the diameter of all colonic polyps exceeds 10mm.     

Prevalence of clinically important histology in small adenomas.

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