Changes in serum cathepsin B-like activity in patients with colorectal cancer

Cathepsin B-like activity (CB-like) was estimated in sera of 30 male patients with colorectal cancer (n = 20), benign polyps of the rectum (n = 10) and in sera of control subjects (n = 50). Both total and residual activities of the enzyme in colorectal cancer patients showed a significant elevation in comparison with control subjects and patients with benign polyps. In the course of antitumor therapy a decline in catheptic activity was observed when a reduction in the volume of tumor tissue was present. On the other hand, an increment in CB-like activity was observed when antitumor therapy had no effects or tumor relapse was present.     

Plasma levels of progastrin but not amidated gastrin or glycine extended gastrin are elevated in patients with colorectal carcinoma

BACKGROUND: The relationship between plasma gastrin levels and colorectal cancer is controversial. When confounding factors which increase plasma gastrin levels are taken into account, it has been shown that gastrin levels are not elevated in patients with colorectal cancer. However, these studies only measured amidated gastrin. Total gastrin (which includes unprocessed, partially processed, and mature forms of gastrin) has been shown to be elevated in patients with colorectal cancer. AIMS: The aim of this study was to determine whether fasting plasma levels of progastrin, amidated gastrin, or glycine extended gastrin are elevated in patients with colorectal cancer or colorectal polyps compared with controls. METHODS: Progastrin, amidated gastrin, and glycine extended gastrin were estimated by radioimmunoassay using the following antibodies: L289, 109-21, and L2. Blood samples were analysed for Helicobacter pylori by an enzyme linked immunosorbent assay. RESULTS: Median progastrin levels were significantly higher in the cancer group (27.5 pmol/l) than in the polyp (< or =15 pmol/l) or control (< or =15 pmol/l) group (p=0.0001 There was no difference in median levels of amidated gastrin between groups. Median levels of amidated gastrin were significantly higher in H pylori positive patients (19 pmol/l) than in H pylori negative patients (8 pmol/l) (p=0.0022). Median plasma progastrin levels were significantly higher for moderately dysplastic polyps (38 pmol/l) compared with mildly dysplastic (15 pmol/l) and severely dysplastic (15 pmol/l) polyps (p=0.05). CONCLUSIONS: Plasma levels of progastrin, but not amidated gastrin or glycine extended gastrin, are significantly elevated in patients with colorectal cancer compared with those with colorectal polyps or controls, irrespective of their H pylori status. We conclude that measuring plasma progastrin levels in patients with colorectal cancer is warranted.     

大肠癌及大肠息肉中端粒酶、PTEN的表达及意义

目的探讨端粒酶和PTEN在大肠癌及大肠息肉中的表达与病理特征的关系及临床意义。 方法应用免疫组织化学(S-P)法检测68例大肠息肉、25例息肉旁正常组织、15例结直肠癌癌灶组织、9例癌旁组织中端粒酶和PTEN蛋白的表达。 结果端粒酶在大肠癌组织中的阳性率(80.00%)显著高于癌旁组织(22.22%)、大肠息肉组织(19.12%)和息肉旁组织(0.00%)。PTEN在大肠癌组织中的阳性率(20.00%)显著低于癌旁组织(77.78%)、大肠息肉组织(54.41%)和正常大肠黏膜组织(80.00%)。在大肠癌及大肠息肉中,端粒酶和PTEN均成负相关(r＝－0.516;r＝－0.261)。端粒酶与息肉大小(r＝0.262)关系密切。端粒酶和PTEN的表达与大肠癌是否有淋巴结转移关系密切(r＝0.560;r＝－0.707)。 结论PTEN在大肠癌中的表达缺失,在腺瘤性息肉表现出缺失倾向,端粒酶和PTEN在大肠癌、大肠息肉中的表达呈负相关。两者的变化可能与结直肠肿瘤的恶性程度和疾病进展有关系。     

胆囊切除与结直肠息肉相关性的研究

背景：胆囊切除已被认为是结直肠癌的危险因素之一,但胆囊切除与结直肠息肉的关系一直未受到重视。目的：探讨胆囊切除与结直肠息肉的相关性。方法：连续收集经结肠镜排除恶性肿瘤、炎症性肠病、家族性腺瘤性息肉病等疾病的患者425例,根据既往有无胆囊切除史分为胆囊切除组（n=63）和对照组（n=362）,对两组患者结直肠息肉的发生率、内镜下息肉表现和组织学类型进行分析。结果：胆囊切除组结直肠息肉发生率高于对照组（46.0%对37.8%）,但差异无统计学意义（P=0.219）。两组患者息肉的部位和形态均无明显差异（P=0.753,P=0.127）;但胆囊切除患者腺瘤性息肉的发生危险显著高于对照组（OR=1.79,P=0.006）。亚组分析示胆囊切除史≥10年的结直肠息肉发生率与胆囊切除史〈10年无明显差异（P=0.11）。结论：胆囊切除并未增加结直肠息肉发生的危险性,但腺瘤性息肉的发生率显著增高,因此对胆囊切除患者应重视早期结直肠癌和腺瘤性息肉的筛查。     

Computed tomographic colonography compared with colonoscopy in patients at increased risk for colorectal cancer

BACKGROUND & AIMS: To date, computed tomographic (CT) colonography has been compared with an imperfect test, colonoscopy, and has been mainly assessed in patients with positive screening test results or symptoms. Therefore, the available data may not apply to screening of patients with a personal or family history of colorectal polyps or cancer (increased risk). We prospectively investigated the ability of CT colonography to identify individuals with large (>or=10 mm) colorectal polyps in consecutive patients at increased risk for colorectal cancer. METHODS: A total of 249 consecutive patients at increased risk for colorectal cancer underwent CT colonography before colonoscopy. Two reviewers interpreted CT colonography examinations independently. Sensitivity, specificity, and predictive values were determined after meticulous matching of CT colonography with colonoscopy. Unexplained large false-positive findings were verified with a second-look colonoscopy. RESULTS: In total, 31 patients (12%) had 48 large polyps at colonoscopy. This included 8 patients with 8 large polyps that were overlooked initially and detected at the second-look colonoscopy. In 6 of 8 patients, the missed polyp was the only large lesion. With CT colonography, 84% of patients (26/31) with large polyp(s) were identified, paired for a specificity of 92% (200-201/218). Positive and negative predictive values were 59%-60% (26/43-44) and 98% (200-201/205-206), respectively. CT colonography detected 75%-77% (36-37/48) of large polyps, with 9 of the missed lesions being flat. CONCLUSIONS: CT colonography and colonoscopy have a similar ability to identify individuals with large polyps in patients at increased risk for colorectal cancer. The large proportion of missed flat lesions warrants further study.     

Decrease in serum levels of vitamin A and zeaxanthin in patients with colorectal polyp.

OBJECTIVE: Several retrospective and prospective epidemiological investigations have demonstrated that a diet rich in carotenoids could prevent the development of pre-cancerous and neoplastic lesions of the digestive tract. The aim of this examination was to analyse the correlation between colorectal polyps with different histological classifications and serum carotenoid levels. DESIGN AND METHODS: A 10 ml blood sample was taken from all of the patients after the colonoscopic diagnosis. The serum levels of vitamin A, lutein, zeaxanthin, alpha- and beta-cryptoxanthin, alpha- and beta-carotene were measured in patients with adenomatous colorectal polyp (n = 59, 35 males, 24 females) by high-pressure liquid chromatography (HPLC) and compared with those in healthy subjects (n = 20, 10 males, 10 females). The patients were separated into four groups depending on their histological findings. RESULTS: The serum levels of vitamin A and zeaxanthin were significantly lower in all patients with polyps (vitamin A: 0.913 +/- 0.112 micromol/l, zeaxanthin: 0.071 +/- 0.012 micromol/l) than in the control healthy group (vitamin A: 2.036 +/- 0.354 micromol/l, zeaxanthin: 0.138 +/- 0.048 micromol/l). The lowest levels were found in patients with focal adenocarcinoma in the polyp. There were no significant differences in the serum levels of other carotenoids. The serum levels of cholesterol, haemoglobin, total protein and albumin were normal in these patients. CONCLUSIONS: There are close and inverse correlations between the serum level of carotenoids and colorectal polyps with different histological grades. The low mean carotenoid levels in patients with adenocarcinoma in the polyp indicate that deficiency of carotenoids may be an important factor in the development of colorectal cancer.     

Increased Serum Type IV Collagen 7-S Levels in Patients with Hepatic Metastasis

Objective: The purpose of this study was to assess scrum type IV collagen 7-S domain (IV 7-S) levels in colorectal cancer patients with hepatic metastasis and to investigate the relation between serum IV 7-S levels and type IV collagenase activities in tumor tissue. Methods: Tissue type IV collagena.se activity and serum IV 7-S were measured in 50 colorectal cancer patients without hepatic metastasis and in 26 patients with hepatic metastasis. Results: Type IV collagenase showed significantly higher activities in colorectal cancer (n = 36) than in colorectal normal mucosa (n = 36) ( p < 0.001), but significantly lower activities were shown in the hepatic metastatic tumor (n = 18) than in the primary tumor (n = 36) and normal liver tissue (n = 18) ( p < 0.001). No significant correlation was (bund between type IV collagenase activities in the tumor and serum IV 7-S levels. Colorectal cancer patients with hepatic metastasis (n = 26) had significantly higher serum IV 7-S levels than those without hepatic metastasis (n = 50) ( p < 0.001). Moreover, serum IV 7-S levels correlated significantly with hepatic metastatic tumor volume in patients with synchronous ( r = 0.719, p < 0.001, n = 26) and in patients with metachronous ( r = 0.910, p < 0.001, n = 16) hepatic metastasis. Conclusion: We suggest that serum IV 7-S levels may increase in hepatic metastasis, not by the degradation of type IV collagen in the primary and secondary tumors, but by the enhanced production of type IV collagen responsive to hepatic metastasis. The measurement of serum IV 7-S levels might be a useful tumor marker of hepatic metastasis reflecting hepatic metastatic tumor volume.     

Prevalence and incidence of hyperplastic polyps and adenomas in familial colorectal cancer: correlation between the two types of colon polyps

BACKGROUND AND AIMS: Colorectal adenomas are recognised as precursors of colorectal carcinomas. The significance of hyperplastic (metaplastic) colorectal polyps is unknown. The relationship between hyperplastic polyps and adenomas, and the prevalence and incidence of these lesions were evaluated in individuals predisposed to familial colorectal cancer. METHODS: A total of 299 individuals participating in our surveillance programme during 1990-2000 were retrospectively evaluated. Subjects were classified into three groups: hereditary non-polyposis syndrome (HNPCC) (n=108), hereditary colorectal cancer (HCRC) (n=127), and individuals with empirical risk estimates-two close relatives (TCR) (n=64). Findings from 780 colonoscopies were evaluated regarding prevalence and incidence of hyperplastic polyps and adenomas. Correlations between hyperplastic polyps and adenomas were calculated by Pearson correlation. RESULTS: In total, 292 hyperplastic polyps and 186 adenomas were observed in 98 and 90 individuals, respectively. A positive correlation was found between the numbers of hyperplastic polyps and adenomas (r=0.40; p<0.001). Correlations between adenomas and hyperplastic polyps were similar in the three groups. The risk of detecting new hyperplastic polyps (odds ratio 5.41) or adenomas (OR 2.56) increased significantly when there was a positive finding at first colonoscopy. CONCLUSION: Hyperplastic polyps as well as adenomas may identify individuals with a high risk of colorectal cancer. This information is important when these individuals are selected and included in tailored surveillance programmes.     

PTEN在大肠癌癌变过程中的表达及意义

目的探讨在大肠癌癌变过程中,即大肠正常组织、大肠增生性息肉、大肠腺瘤和大肠癌中PTEN的表达及意义。方法应用免疫组织化学SP法检测122例大肠组织标本中PTEN蛋白的表达,应用等级相关的秩和检验分析PTEN在大肠组织中表达的意义及其与临床病理特征间的关系。结果PTEN蛋白在正常大肠组织、大肠增生性息肉、大肠腺瘤、大肠癌中表达差异有明显统计学意义（P=0．000）。大肠癌中PTEN蛋白表达与肿瘤分化程度、临床肿瘤分期及性别无关（P〉0．05）,但与患者的年龄相关（P=0．002）。结论PTEN蛋白在大肠癌癌变过程中存在异常表达,PTEN蛋白的低表达与大肠癌的发生和浸润转移相关。     

Colorectal cancer screening in patients presenting with an inguinal hernia: is it necessary?

BACKGROUND: It has been suggested that patients presenting with an inguinal hernia have an increased risk for colorectal cancer. Therefore, surgeons frequently request screening for colorectal cancer before surgery. The aim of this study was to assess the frequency of premalignant and malignant colonic lesions in a group of patients with an inguinal hernia, and to compare this with a control group of subjects undergoing screening colonoscopy. METHODS: In a case-control study, 243 patients with an inguinal hernia and no history of colonic neoplasia or symptoms suggestive of colorectal cancer underwent perioperative colonoscopy. The patients were stratified into two age groups: less than 50 years old (Group I) and more than 50 years old (Group II). The colonoscopic findings were compared with findings in 534 asymptomatic control patients who underwent screening colonoscopy. RESULTS: The mean age of patients (n=64) and control subjects (n=200) in Group I was similar, at 44 (3) years. The mean age of the patients (n=179) and control subjects (n=334) in Group II was, respectively, 70 (9) years and 64 (7) years (p<0.001). In Group I, no colorectal cancer was found in patients with inguinal hernia, and only one colorectal cancer was found among control subjects (p=0.571). In Group II, a diagnosis of colorectal cancer was made in 7 patients (4%) with inguinal hernia as compared with 10 patients (3%) among the control subjects (p=0.769). In both groups, the size and the histopathologic type of the polyps were not significantly different. CONCLUSIONS: In otherwise asymptomatic patients, the presence of inguinal hernia is not associated with an increased risk for colorectal cancer. Therefore, the presence of an inguinal hernia alone does not justify screening colonoscopy before herniorrhaphy.     

Faecal unconjugated bile acids in patients with colorectal cancer or polyps.

The unconjugated faecal bile acid profiles of 14 patients with colorectal cancer, nine patients with polyps and 10 controls were compared using gas liquid chromatography, controlling for such confounding variables as cholecystectomy, gall stones and hepatic function. Patients with adenomatous polyps had a higher concentration of faecal bile acids (5.23 mumol/g, 2.16-13.67 (median, range) v 1.96, 0.91-6.97; p = 0.016) lithocholic acid (2.41, 0.88-3.22 v 1.07, 0.38-2.03; p = 0.013) and total secondary bile acids (5.23, 2.16-13.4 v 1.96, 0.73-6.63; p = 0.02) compared with control subjects. Patients with colorectal cancer had an increased (p = 0.029) proportion of secondary faecal bile acids (mol%) compared with controls (100, 96.5-100 v 95.19, 81.73-100) and the ratios of the primary bile acids, cholic and chenodeoxycholic acid, to their respective derivatives (secondary bile acids) were significantly lower in cancer patients compared with control and patients with polyps (p = 0.034 to 0.004). This study lends further support to the theory that bile acids may play a role in the development of polyps and colorectal cancer.     

Erythrocyte stearic acid desaturation in patients with colorectal carcinoma

The erythrocyte stearic:oleic acid ratio (saturation index) was investigated as a means of differentiating between control subjects (n = 146) and patients with benign (n = 48) and malignant (n = 117) colorectal disease and patients undergoing postoperative follow-up after curative resection (n = 49). Erythrocyte fatty acid profiles were determined by gas liquid chromatography. Neither age, sex, Dukes' stage, nor degree of differentiation of the tumors had a significant effect on the erythrocyte saturation index. The erythrocyte saturation index was lower in patients with primary and recurrent colorectal cancer compared with control subjects and patients with inflammatory bowel disease or benign colonic polyps (P less than 0.0001). The erythrocyte saturation index was not found to be useful in the postoperative follow-up of these patients. Using both saturation index and age as a means of differentiating between patients with primary colorectal cancer and control subjects gave a sensitivity of 67 percent and a specificity of 81 percent.     

COX-2、15-PGDH在结直息肉组织中的表达及其作用

目的:探讨环氧合酶-2(COX-2)和15-羟基前列腺素脱氢酶(15-PGDH)在结直肠息肉组织中的表达及在息肉恶变中的作用.方法:选取2009-02/2009-10肠镜下摘除的结直腺瘤性息肉48例及增生性息肉25例,活检或外科手术的结直肠腺癌15例及正常结肠黏膜15例作为对照.采用RT-PCR和Western blo...     

Plasma Levels of Matrix Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-1 Correlate With Disease Stage and Survival in Colorectal Cancer Patients

PURPOSE The matrix metalloproteinases and their inhibitors are known to be involved in the process of tumor invasion and progression. Our objective was to investigate the potential diagnostic and prognostic value of plasma matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 in colorectal cancer.METHODS Gelatinase bioactivity and immunoreactivity of pro-matrix metalloproteinase-2 and -9, tissue inhibitor of metalloproteinase-1, and carcinoembryonic antigen were determined simultaneously in preoperative plasma and serum of colorectal cancer patients (n = 94) and in healthy controls (n = 51).RESULTS Plasma pro-matrix metalloproteinase-2 levels were lower in colorectal cancer patients (P < 0.0001) than in controls, and its gelatinolytic activity revealed an inverse correlation with adverse clinicopathologic parameters, such as lymph node involvement (P = 0.017), stage (0, I, II vs. III, IV; P = 0.012), and the carcinoembryonic antigen level (P = 0.016). Pro-matrix metalloproteinase-9 levels did not differ between patients and controls. Pro-matrix metalloproteinase-2 gelatinolytic activity showed potential value in colorectal cancer diagnosis, identifying patients with 70 percent sensitivity at 95 percent specificity. Pro-matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and carcinoembryonic antigen all showed lower sensitivities. Combining pro-matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 measurements increased the sensitivity significantly to 84 percent. With respect to prognosis, tissue inhibitor of metalloproteinase-1 showed value in predicting disease outcome in our patient group, whereas pro-matrix metalloproteinase-2 and -9 did not. The combination of tissue inhibitor of metalloproteinase-1 and carcinoembryonic antigen was better in predicting three-year survival than tissue inhibitor of metalloproteinase-1 alone, but it remains to be determined if the combination would be a better marker for survival than carcinoembryonic antigen alone.CONCLUSIONS Low pro-matrix metalloproteinase-2 levels and high tissue inhibitor of metalloproteinase-1 levels correlate with parameters of colorectal cancer disease. These correlations may be used in the search for new markers in colorectal cancer diagnosis and prognosis.This work was supported by the Dutch Cancer Society (grant KUN 97-1380).     

Role of circulating gastrin in colorectal adenomas and carcinomas

BACKGROUND/AIMS: A trophic role of gastrin has been convincingly demonstrated in the oxyntic mucosa of the stomach, but is still a matter of debate in the lower gastrointestinal tract. METHODS: In order to examine the role of circulating gastrin in colorectal adenoma and carcinoma fasting serum gastrin concentrations were determined in 351 patients undergoing complete colonoscopy. RESULTS: In comparison to controls (n = 145) more patients with either polyps (n = 125) or colorectal carcinoma (n = 81) have slightly increased serum gastrin concentrations, leading to an increased mean, but no change in median serum gastrin levels. In 3 patients preoperatively increased serum gastrin concentrations were normalized after surgical removal of the polyp and/or tumor, suggesting a local release of gastrin from the polyp/tumor. Gastrin concentrations do not correlate with the histopathological classification or malignant potential of adenomatous polyps. CONCLUSION: In view of these findings a significant role of circulating endogenous gastrin in human colorectal carcinogenesis seems to be unlikely.     

Frequency of colorectal polyps in patients with sporadic adenomas or adenocarcinomas of the papilla of vater--an age-matched, controlled study

BACKGROUND: Epithelial tumors of the papilla of Vater are rare neoplasms of the gastrointestinal tract. The carcinogenesis of these tumors seems to be fairly analogous to the genetic mechanisms which have been described for colorectal carcinoma. Patients with familial adenomatous polyposis bear a particularly increased risk for periampullary tumors. Data on whether the prevalence of colorectal tumors is increased in patients with sporadic ampullary neoplasms are scarce. METHODS: 26 consecutive patients (16 women, 10 men; median age 59 years) with sporadic adenomas (n = 19) or adenocarcinomas (n = 7) of the ampulla of Vater were retrospectively evaluated. The study patients were compared with 104 age-matched asymptomatic controls. All patients had undergone total colonoscopy. RESULTS: Neoplastic colorectal polyps were present in a similar proportion (23%) of patients of the study group compared with 26% in the control group (p > 0.05). Overall, 16 polyps were found among patients with ampullary tumors and 40 in asymptomatic controls (p > 0.05). Colonoscopy detected rectal carcinoma in 2 patients (8%) of the study group. Patients with and without colorectal polyps differed neither significantly by age nor by ampullary histological findings. 50% of the colonic polyps in patients with ampullary neoplasms were located in the ascending colon. CONCLUSIONS: The frequency of colorectal polyps in patients with ampullary tumors did not exceed the risk in the control group. However, the finding of 2 rectal carcinomas among patients with ampullary neoplasms supports the place of screening colonoscopy for the diagnostic work-up of ampullary tumors. Prospective multicenter studies should address this issue to provide a broad basis for future recommendations.     

Endoscopic Treatment of Colorectal Polyps and Early Cancer

To analyze the efficacy and outcome of colonoscopic resection for colorectal neoplastic lesions, we retrospectively reviewed 338 colorectal lesions from 232 patients regarding the clinical profiles, colonoscopic findings, histological findings, complications, and outcome. Morphologically, these lesions were classified into three categories: pedunculated (n = 140), sessile (n = 176); and flat (n = 22). Histological findings of lesions included adenoma (n = 248), carcinoma in situ (n = 17), submucosal carcinoma (n = 2), hyperplastic polyp (n = 57), and inflammatory polyp (n = 14). Neoplastic lesions are generally larger than nonneoplastic lesions (² test, P < 0.05). The incidence of carcinoma was 5.6% of 338 resected lesions. The rate of cancer or high-grade dysplasia in flat polyps was greater than in pedunculated and sessile polyps (13.6 vs 4.54 vs 5.71%; P < 0.05). There were no perforations or deaths after colonoscopic treatment, and only mild bleeding occured in two patients. To date, 19 patients with early colorectal cancer were treated successfully by endoscopy with no recurrence or metastasis. To reduce the incidence and mortality of colorectal cancer, colonoscopic resection is a simple and safe procedure for removing neoplastic lesions. Detailed histological examinations are essential to decide the indications of surgery.     

非甾体抗炎药预防结直肠息肉的系统评价

目的　评价非甾体抗炎药 (NSAIDs )是否能降低结直肠息肉发生的危险性 ,以及长期使用这些药物的安全性。方法　应用国际Cochrane协作网的系统评价方法对全世界关于NSAIDs与安慰剂或空白对照比较的随机临床对照试验进行系统评价。结果　共有 8篇随机临床对照试验被纳入评价。分析结果显示阿司匹林可以预防结直肠腺瘤的发生 (P =0 0 0 3 ) ,但没有证据支持长期使用苏林酸和塞来昔布可以减少结直肠腺瘤发生的危险性 (P >0 0 5) ,也无证据证明结直肠腺瘤预防与NSAIDs的剂量有关。无论使用阿司匹林还是安慰剂 ,结直肠癌发生的机会相似 (P =0 8)。未发现NSAIDs和安慰剂组间不良反应有差异。结论　在结直肠腺瘤或结直肠癌术后的患者 ,长期使用阿司匹林可减少腺瘤的发生 ;目前尚无常规剂量阿司匹林可减少结直肠癌发生的证据 ,也无长期使用苏林酸和塞来昔布可减少结直肠腺瘤发生危险性的证据     

Endoscopic Removal of Large Colorectal Polyps

PURPOSE: Because of the potential risk of malignancy and technical difficulties in achieving complete removal, large colorectal polyps represent a special problem for the endoscopist. The aim of this study was to evaluate the capabilities and risks of endoscopy in complete removal of large colorectal polyps. METHODS: Endoscopic polypectomy of 186 colorectal polyps larger than 3 cm in diameter (range, 3-13 cm) was performed; 141 were sessile and 45 pedunculated. Most of the polyps were located in the rectum (n = 88), sigmoid (n = 63), and cecum (n = 9). The remaining adenomas were situated in other parts of the colon. Sessile polyps were removed using the piecemeal technique. RESULTS: Histology results showed an adenoma in 167 cases, and invasive carcinoma was present in the adenoma in 19 patients. Of the adenomas, 29 were tubulous, 118 tubulovillous, and 20 villous; adenoma with severe dysplasia was found in 49 cases. Complete endoscopic removal was achieved in all sessile and pedunculated polyps. None of the patients with invasive carcinoma who underwent surgical resection (n = 10) had any evidence of tumor in the resected specimen. Bleeding occurred in 4 patients after polypectomy (2 percent). Perforation occurred in 1 patient (0.5 percent), who had an invasive carcinoma of the cecum. There was no procedure-related mortality. During a mean follow-up period of 40 (range, 3-87) months, 6 patients presented with recurrence of a benign adenoma (3 percent), which was treated endoscopically, and 1 patient presented with a recurrent invasive carcinoma, which was treated surgically. CONCLUSIONS: Endoscopic polypectomy is a safe and effective method of treating large colorectal polyps.