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PubMed1982

Adenocarcinoma occurring in a hyperplastic (metaplastic) polyp of the colon.

A case of adenocarcinoma occurring in a hyperplastic (metaplastic) polyp of the colon is presented. The polyp, two cm in diameter, was located in the transverse colon of a 45-year-old male patient, and was removed endoscopically. From the periphery to the centre, the polyp showed epithelial changes progressing from hyperplastic to severely dysplastic, terminating in a central focus of invasive adenocarcinoma. It is suggested that the considerable number of absorptive cells in large hyperplastic polyps may occasionally result in an excessive absorption of carcinogen thus leading to dysplastic changes.

Adenocarcinoma↗
PubMed2002

CT colonography (virtual colonoscopy) for the detection of colorectal polyps and neoplasms. current status and future developments.

Computed tomography colonography (CTC) is a new, rapidly developing non-invasive CT technique used to detect colonic polyps and cancers. It employs two- (2D) and three-dimensional (3D) images of the colon in order to display neoplastic lesions. Clinical trials demonstrate promising results for the detection of polyps and cancers greater than or equal to 10 mm in size. Our purpose is to describe the technique of CT colonography, review recent published trials of CT colonography, and elucidate current clinical applications. Continuing technical innovations such as multidetector CT, computer-aided diagnosis, new image display techniques and faecal tagging promise to improve the performance and patient acceptance of CT colonography in the future.

Adenomatous Polyposis Coli↗
PubMed1997

Influence of prophylactic local administration of epinephrine on bleeding complications after polypectomy.

BACKGROUND AND STUDY AIMS: Data concerning the potential benefit of local application of vasoconstricting substances prior to snare excision of colonic polyps are scarce. The influence of prophylactic submucosal injection of epinephrine in the prevention of hemorrhage after polypectomy was therefore evaluated in larger polyps. PATIENTS AND METHODS: Seventy-three patients, in whom 77 polyps more than 15 mm in diameter had been excised during a 30-month period, were included in this retrospective analysis. Twenty-eight polyps were excised with prophylactic injection of epinephrine into the polyp base, and 49 polyps were excised without the injection. All data were retrieved by reviewing the medical records. RESULTS: No bleeding occurred in the epinephrine group (28 polyps). In contrast, nine of the 49 polypectomies that were carried out without prior administration of epinephrine were associated with a bleeding episode (P = 0.015). CONCLUSIONS: Local injection therapy appears to reduce the risk of bleeding after the excision of larger polyps. Controlled trials are warranted in order to provide conclusive evidence concerning the prophylactic effect of epinephrine on hemorrhage after polypectomy.

Blood Loss, Surgical↗
PubMed2005

Combined laparoscopic near-total gastrectomy and colectomy.

Synchronous gastrointestinal lesions of the abdomen are uncommon. Although laparoscopic gastric resection and colonic resection have been previously described, the combined laparoscopic resection of these 2 organs is unique. We report a case of a 72-year-old man with in situ gastric cancer and high-grade dysplasia of a colon polyp who underwent successful laparoscopic resection of both lesions. This report highlights the importance of preoperative planning and port placement in combined laparoscopic procedures.

Aged↗
PubMed2004

Two cases of inverted hyperplastic polyps of the colon and association with adenoma.

Here we report two cases of inverted hyperplastic polyps of the colon. The first patient showed three inverted hyperplastic polyps in the ascending colon, one of which was associated with adenoma. We immunostained this adenoma-associated polyp using anti-beta-catenin antibody and found accumulation of beta-catenin in the cytoplasm of the adenomatous lesion but not in the inverted hyperplastic polyp. This suggested an adenomatous polyposis coli (APC) mutation in the adenomatous region but not in the inverted hyperplastic polyp. The inverted hyperplastic polyp in the second patient was located at the caecum and was studied using magnifying colonoscopy. The polyp appeared to be flat and elevated with a depressed pit in the centre. After spraying with methylene blue dye, the pit pattern of the lesion was observed and small asteroid pits on the polyp were found, consistent with a hyperplastic gland pattern. From these results, we diagnosed inverted hyperplastic polyp of the colon by colonoscopy.

Adenoma↗
PubMed2000

Effect of cholesterol levels on villous histology in colonic adenomas.

To date no studies have examined the relationship between cholesterol levels and the occurrence of specific colonic polyp histologies. Villous histology has a greater predilection for subsequent malignancies than other histologies. Consequently, we examined the effect of cholesterol levels on the occurrence of villous adenomas. Just under one in 10 (9.5%, 15/158) patients had polyps with villous histologies. Cholesterol levels were positively and nonlinearly associated with a greater likelihood of villous histology, suggesting that a threshold exists for the effect of cholesterol level on the likelihood of having polyps with villous histology [odds ratios (OR) for combined two variable quadratic effect: cholesterol OR, 1.18; 95% confidence interval (CI), 1.02-1.37 and cholesterol squared OR, 1.004; 95% CI, 1.00-1.02]. Our data suggest that, in patients with polyps, higher cholesterol levels increase the likelihood of having polyps with villous histology, but that the effect of cholesterol level reaches a threshold.

Adenoma, Villous↗
PubMed2003

Birt-Hogg-Dubé syndrome.

We present three members of a Queensland family with clinical and histopathological features consistent with Birt-Hogg-Dubé syndrome. Two of the three family members were able to be screened for associated disorders. The mother of the family was found to have a solitary colonic polyp, a large ovarian cyst and two chorioretinal scars. No associated disorders were found on investigation of one of the two affected sons.

Adult↗
PubMedDate not supplied

Possible mechanism pertinent to mucosal invasion in sporadic colonic adenomas.

Colorectal adenomas are foci of dysplastic mucosa that may antedate the development of a colorectal cancer. In this work we investigated 62 colonic polyps. A close examination revealed that in some adenomatous glands facing the muscularis mucosa a group of dysplastic cells were missing. Those glandular defects were connoted as glandular pores. Many glands with pores were dilated and had retained mucin, inflammatory cells and/or necrotic material. Those products were often released through the pores into the surrounding lamina propria. Glandular pores were recorded in 25% (3/12) of the tubular adenomas, in 33% (2/6) of the serrated adenomas, in 50% (4/8) of the tubulo-villous adenomas and in 67% (14/21) of the villous adenomas. None of the 14 hyperplastic polyps had glandular pores. While cell locomotion is considered to be the most important parameter accountable for the local progression of tumors, the present results may offer an alternative view to the cell-migration theory (as the sole pathway of invasion). The release of proteolytic secretions through glandular pores in some colonic adenomas disrupt the surrounding matrix, a mechanism that would facilitate neoplastic cell penetration into the lamina propria.

Adenoma↗
PubMed2006

Expression and localisation of kinin receptors in colorectal polyps.

Kinins increase vascular permeability as well as mitogenesis and proliferation, hence they have a potential to promote neoplasmatic transformation. In the present study we investigated the expression profile and localization of kinin B1 and B2 receptors in colorectal polyps. The biopsy samples from various polyps were obtained during endoscopy in tubular (n=18), villous (n=15) and hyperplasic polyps (n=15). The expression of genes encoding B1 and B2 was estimated by QRT-PCR TaqMan analysis. In second series B1 and B2 receptors were visualized by immunohistochemical staining in tissue specimens from colonic polyps and adjacent normal tissue. We found the highest expression of gene encoding B1 in tubular adenomas (1891 number of copies mRNA/microg total RNA+/-312 SE) which is significantly higher as compared with controls (683+/-197 SE, p<0.013). In contrast, the expression of gene for B2 was significantly increased in hyperplastic polyps (3852+/-936 SE) as compared with controls (843+/-263 SE, p<0.0016). In normal colon a well as in hyperplasic polyps B1 and B2 receptors were immunohistochemically localized in enterocytes, however in hyperplastic polyps the intensity of staining was more prominent for B2 comparing to the control group. In contrast, in tubular adenomas staining reaction for B1 was more intense than in control samples. Increased level of B1 in adenoma suggests that kinins may play a role in abnormal cellular transformation; whereas higher B2 level in hyperplasic polyp suggests its protective role. Our data may indicate that the overall effect of kinins on cellular proliferation depends on the relative level of B1 and B2 receptor expression.

Adenoma↗
PubMed1994

Steady-state serum concentration of alpha tocopherol not altered by supplementation with oral beta carotene. The Polyp Prevention Study 1 Group.

BACKGROUND: The antioxidants beta carotene and vitamin E may play a role in cancer prevention. However, some studies have suggested that oral supplements of beta carotene may cause a decrease in serum levels of alpha tocopherol (vitamin E). PURPOSE: We conducted this study to determine if beta carotene supplements affect serum levels of vitamin E and vice versa. METHODS: Five hundred five patients in a clinical trial of antioxidant vitamins, used to prevent recurrences of colonic polyps, received either a placebo, 25 mg of beta carotene per day, 1 g ascorbic acid plus 400 mg alpha tocopherol per day, or all three agents combined. Serum levels of beta carotene and vitamin E were measured before and after 9 months of supplementation, using high-performance liquid chromatography. RESULTS: Vitamin E levels changed very little among the groups receiving placebo or beta carotene and went up substantially and equally in the groups receiving vitamin E plus ascorbic acid or all three agents together. Conversely, beta carotene levels changed very little for the groups receiving placebo or ascorbic acid plus vitamin E but went up substantially and equally for the groups receiving beta carotene alone or all three agents. CONCLUSIONS: We conclude that oral supplementation with beta carotene for 9 months does not alter serum concentration of vitamin E and that supplementation with vitamin E plus ascorbic acid does not alter serum beta carotene levels.

Administration, Oral↗
PubMed2000

Expression of pituitary-tumour transforming gene in colorectal tumours.

BACKGROUND: Basic fibroblast growth factor promotes angiogenesis and mitogenesis in colon carcinomas. Pituitary-tumour transforming gene (PTTG1) causes in-vitro and in-vivo transformation, regulates secretion of basic fibroblast growth factor, and inhibits chromatid separation. Most normal tissues show little or no PTTG1 expression but cancer cells express the gene abundantly. We postulated that PTTG1 expression in colorectal tumours is related to tumour invasiveness. METHODS: PTTG1 gene and protein expression were assessed in 68 colorectal tumours and compared with invasive characteristics, such as lymph-node invasion, evidence of metastases, tumour vessel density, and expression of basic fibroblast growth factor. PTTG1 expression is given in terms of the fold-increase over that in normal-adjacent colorectal tissue. FINDINGS: PTTG1 was overexpressed in all of 48 colon carcinomas (median fold-increase 2.2 [IQR 1.8-3.3]) and in 19 of 20 colonic polyps (2.2 [1.6-3.1]) compared with normal colonic tissue. Invasion of surrounding lymph nodes was associated with higher PTTG1 expression than in carcinomas limited to the bowel wall (3.4 [2.1-5.9] vs 1.9 [1.7-2.4], p=0.007), and higher PTTG1 expression was seen in more vascular than in less vascular tumours (2.6 [1.9-5.1] vs 1.9 [1.8-2.5], p=0.04). INTERPRETATION: Increased tumour PTTG1 expression may be a marker of invasive colorectal carcinoma and could represent a new therapeutic target.

Colorectal Neoplasms↗
PubMed2002

PTEN and TNF-alpha regulation of the intestinal-specific Cdx-2 homeobox gene through a PI3K, PKB/Akt, and NF-kappaB-dependent pathway.

BACKGROUND & AIMS: PTEN (phosphatase and tensin homologue deleted from chromosome 10) is a dual-specificity phosphatase implicated in embryonic development, intestinal cell proliferation and differentiation, and tumor suppression. The transcription factor Cdx-2 is critical in intestinal development and homeostasis, and its expression is altered in colorectal cancers. However, the regulation of the Cdx-2 gene has not been entirely elucidated. Here, we hypothesize that Cdx-2 may be a target of PTEN signaling in the intestine. METHODS: The expression patterns for Cdx-2 and PTEN along wild-type mouse colon, as well as in colon tumors occurring in Pten(+/-) mice, were examined. The effect of PTEN or phosphatidylinositol 3-kinase inhibition and tumor necrosis factor alpha on Cdx-2 messenger RNA and protein expression, Cdx-2 DNA binding activity, and the promoter activity of the Cdx-2 gene was analyzed in human colon cancer cell lines. RESULTS: Cdx-2 expression correlates with PTEN along the length of the murine colon and in colonic polyps that develop in Pten(+/-) mice. In colon cancer cells, PTEN stimulates Cdx-2 protein expression and the transcriptional activity of the Cdx-2 promoter. Phosphatidylinositol 3-kinase inhibition by wortmannin or by a dominant-negative phosphatidylinositol 3-kinase mimics the Cdx-2 stimulation by PTEN. Inversely, cell treatment by tumor necrosis factor alpha decreases Cdx-2 expression. Phosphatidylinositol 3-kinase inhibition by PTEN or wortmannin has an inverse effect compared with tumor necrosis factor alpha on the balance between the p50 and p65 subunits of nuclear factor kappaB. p65 inhibits the activity of the Cdx-2 promoter, whereas p50 prevents p65 action. CONCLUSIONS: Our results suggest that the intestinal Cdx-2 homeobox gene is a target of PTEN/phosphatidylinositol 3-kinase signaling and tumor necrosis factor alpha signaling via nuclear factor kappaB-dependent pathways.

Androstadienes↗
PubMed2006

Push-and-pull enteroscopy using a single-balloon technique for difficult colonoscopy.

BACKGROUND AND STUDY AIMS: Several factors predict difficult or incomplete colonoscopy with a standard colonoscope, including female gender, low body mass index, extensive diverticulosis, and prior pelvic surgery. PATIENTS AND METHODS: A push-and-pull enteroscopy device and a single-balloon technique was used in 14 patients (six men, eight women; mean age 62 +/- 15 years) after failure of ileocolonoscopy or endoscopic therapy using either a standard or a pediatric colonoscope. The original ileocolonoscopy had been performed to investigate colon polyps (n = 6), an obscure inflammatory process in the ileocecal region (n = 6), or iron deficiency anemia with a positive fecal occult stool test (n = 2). RESULTS: Ileocolonoscopy was successfully performed using this push-and-pull technique in all 14 patients without technical problems or complications. All the endoscopic therapeutic interventions that were required were also performed without complications, with the exception of one instance of bleeding. Multiple polyps were found in six patients; a colon cancer was found in one patient; appendicitis combined with a carcinoid tumour of the appendix was diagnosed in one patient; ileocolitis was observed in two patients; one patient with Crohn's disease had stenoses in the region of an anastomosis; and in three patients no relevant pathological finding was seen. CONCLUSION: It was possible to perform ileocolonoscopy with therapeutic interventions using this new thin push-and-pull enteroscopy device with a single-balloon technique in patients who had previously undergone incomplete colonoscopy using a standard colonoscope.

Adult↗
PubMedDate not supplied

Malignancy after liver transplantation in patients with premalignant conditions.

GOALS: Liver transplant recipients are at increased risk of developing nonhepatic malignant tumors. The aim of the current study was to evaluate the role of premalignant states, not associated with the liver disease prior to transplantation, in the development of posttransplantation malignancy. STUDY: One hundred seventy-five patients who had undergone liver transplantation were retrospectively evaluated for the development of malignant conditions. Each of the patients who developed malignancy following transplantation was evaluated for the presence of premalignant conditions before transplantation. RESULTS: Post-liver transplantation malignancy was identified in 13 patients (7.4%). Five patients developed non-Hodgkin lymphoma: four had posttransplantation lymphoproliferative diseases, and one had B cell lymphoma of the stomach. Eight patients developed solid tumors. In five of these patients, evidence of a premalignant state was identified: ulcerative colitis was diagnosed in 1 patient with carcinoma of the colon; colonic polyp, 1 patient with carcinoma of the colon; Barrett esophagus, 1 patient with esophageal carcinoma; Caroli disease, 1 patient with anaplastic cholangiocarcinoma; and cervical atypia, 1 patient with carcinoma of the cervix. CONCLUSIONS: Premalignant conditions existing before transplantation, which are not associated with the primary liver disease, are major risk factors for posttransplantation malignancy. Screening for premalignant conditions should be included in pretransplantation evaluation. Liver transplant patients with evidence of a premalignant state should be followed after transplantation for detection of malignancy.

Adult↗
PubMed1983

Monoclonal antibodies for carcinoembryonic antigen and related antigens as a model system: a systematic approach for the determination of epitope specificities of monoclonal antibodies.

A systematic approach for the determination of epitope specificities of monoclonal antibodies to a complex antigen system is described. After initial screening to identify antigen-binding monoclonal antibodies, one or more of the clones are isolated by limiting dilution cloning, grown in ascites, and the resulting antibodies secreted into the ascitic fluid are affinity purified on Sepharose-bound protein A, radiolabeled, and cross-compared with antibodies from other clones by a solid-phase competitive immunoassay. In this work, BALB/c mice were immunized with either purified carcinoembryonic antigen (CEA) or the CEA-producing cell line HC 84S. Spleen cells were fused with the mouse myeloma cell line Sp2/0-Ag14. The supernatants from 25 hybrids showed a significant binding of 125I-CEA (greater than or equal to 15%). Nine hybrids were cloned, resulting in 33 different clones. The antibodies produced by the different cloned hybrids and the remaining uncloned hybrids recognized a total of five different epitopes on CEA. All of the epitopes reside on the protein moiety of the molecule as determined by antibody binding to deglycosylated CEA. The monoclonal antibodies with five different epitope specificities were reacted with tissue sections of normal and cancerous tissues and with peripheral blood smears. Each of the five monoclonal antibodies reacted with tissue sections from colonic, gastric, lung, and mammary carcinomas, as well as from a benign colonic polyp and a resection margin from a colonic carcinoma. Four monoclonals reacted with normal liver tissue. Granulocytes in peripheral blood smears bound three antibodies strongly and one antibody weakly, and one antibody was not bound. One monoclonal antibody that reacted with normal liver tissue was not bound by granulocytes. The ability of these five monoclonal antibodies to differentially detect three different CEA-related antigens in normal and malignant tissues may have clinical utility.

Animals↗
PubMed1997

New methods of polypectomy.

The three most prominent advances in colonoscopic polypectomy are the submucosal injection of saline to ensure safety of polypectomy, the use of the small, or mini, snare for removal of most colon polyps, and the introduction of the argon plasma coagulator for the treatment of vascular abnormalities of the colon and the fulguration of residual adenoma at the base of sessile polyps with a noncontact technique. The role of Endoloop, endoscopic clips, and rubber band ligation for polypectomy is discussed.

Argon↗