PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Colorectal Neoplasms”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2003

[CT-colonography with the 16-slice CT for the diagnostic evaluation of colorectal neoplasms and inflammatory colon diseases].

PURPOSE: Comparison of the performance of virtual and conventional colonoscopy for the detection of colorectal polyps and inflammatory colon diseases using a 16-slice spiral CT scanner. Furthermore, presentation of the first experiences with a new three-dimensional reconstruction mode ("colon-dissection") that dissects the colonic wall like a pathologic-anatomic preparation to increase the sensitivity. MATERIALS AND METHODS: Forty patients were studied using a 16-slice spiral CT (Lightspeed 16, General Electric Medical Systems, Milwaukee, Wisconsin 53201, USA). The examination was performed after standard oral preparation for colonoscopy. The colonic distension was achieved with room air and intravenous butylscopolamine. Images were obtained in supine and prone position using a detector configuration of 16 x 0.625 mm, pitch 1.7, rotation time 0.5 s, 160 mAs and 120 kV. Axial reconstruction with a slice thickness of 0.625 mm. The CT data were assessed by two radiologists on an Advantage Workstation (Volume Analysis 2, USA) using a software with the capabilities of axial, multiplanar and volume rendering, virtual endoscopy, and colon dissection. Conventional colonoscopy was used to determine the sensitivity. RESULTS: A total of 30 polyps were found in 8 patients and a carcinoma was detected in two patients. Colonography identified 4 polyps with a diameter of 10 mm or more, 6 polyps with a diameter of 5 mm to 9.9 mm, 11 polyps with a diameter of 3 to 4.9 mm and 9 polyps with a diameter of 3.0 mm or less. There were two false negative findings (one polyp of 3 mm and one of 4 mm had been overseen) and two false positive findings for polyps (polyps of 4 mm and 6 mm). The sensitivity and specificity for the detection of colonic polyps were 93% and 94% with the "colonic-dissection" mode, 87 % and 94 % with the "virtual-endoscopy" mode and 63 % and 97 % with multi-planar reconstruction, respectively. Depending on the diameter of the colonic polyps, the "colon-dissection" mode ("virtual-coloscopy") had a sensitivity and specificity of 100 % and 100 % for polyps with a diameter over 5.0 mm, 91 % and 82 % for polyps with a diameter from 3.0 to 4.9 mm and 89 % and 78 % for polyps with a diameter under 3.0 mm, respectively. Inflammatory colon diseases presented as thickening of the colon wall over 5 mm. CONCLUSIONS: Virtual colonoscopy with 16-slice spiral CT allows accurate detection of colonic polyps, including small polyps below a diameter of 3 mm. In comparison with the 2D- and 3D-"virtual-endoscopic" reconstruction, the 3D-reconstruction software "colon-dissection" achieves the highest sensitivity for the detection of colonic masses. Therefore, the combination of a 16-slice spiral CT and the "colon-dissection" reconstruction software provides a high resolution in the z-axis for detecting colonic masses and polyps down to a diameter of less than 2 mm, with a sensitivity of about 90 %. This sensitivity is much higher than the sensitivity achievable with 4-slice spiral CT and without "colon-dissection" mode. A thickened colon wall over 5 mm indicates inflammatory colon disease.

Colonic Polyps↗
PubMed1994

[Differences in serum selenium concentration in probands and patients with colorectal neoplasms in Zagreb, Croatia].

Serum selenium concentration (scSe) (microgram/l) was comparatively measured in healthy persons (n = 202), patients with colorectal adenoma(s) (n = 44) and colorectal carcinoma (n = 48). In patients with adenoma(s) scSe (59.05 +/- 15) was significantly lower (p < 0.001) compared with scSe in the control group (66.8 +/- 14.43). Hyposelenemia was more pronounced in patients with multiple polyps (n = 11) than in patients with single adenoma (n = 33) (p < 0.05). Patients with colorectal carcinoma had also significant decrease in scSe (50.93 +/- 13.81) compared with the control group (p < 0.001 and with the adenoma patients (p < 0.001). According to the analysis of variance, highly significant differences were found among the cancer patients stratified in Dukes' stages A to D (p < 0.001), indicating a strong negative correlation between extension of cancer and hyposelenemia. Furthermore, hyposelenemia seemed to be more pronounced in the mucinous type of carcinoma than in adenocarcinoma (p = 0.056). This results indicate that hyposelenemia is strongly associated with colorectal neoplasia (including extension and severity of the disease) and that it may not only be a result but also one of tumorogenic factors. That means that selenium supplementation could be important in prevention or even adjuvant therapy of colorectal cancer.

Adenomatous Polyposis Coli↗
PubMed2005

[Radiosensitivity on colorectal neoplasms by recombinant adenoviral-mediated wild-type p53 gene].

OBJECTIVE: To study the radiosensitization on the cells of colorectal cancer transfected with recombinant adenovirus vector-mediated wild-type p53. METHODS: SW480 cells transfected by wild-type p53 were treated with 4 Gy and 6 Gy radiation. The expression of recombinant adenovirus vector-mediated wild-type p53 gene was detected by Western blotting. The inhibition rate of SW480 cells was examined by MTT, apoptotic rate by TdT-mediated dUTP nick end labeling (TUNEL) and proliferating cell nuclear antigen (PCNA) by immunohistochemical method. RESULTS: SW480 cells transfected by wild-type p53 were inhibited significantly by 4 Gy and 6 Gy radiation. The level of apoptosis increased and the expression of PCNA decreased. CONCLUSION: Cells of colorectal carcinoma transfected with wild-type p53 increases their radiation sensitivity.

Adenoviridae↗
PubMed2004

[Structural features of GR6 gene and its expression in colorectal neoplasm].

OBJECTIVE: To determine the characteristics of GR6 gene and putative GR6 protein, and to evaluate the expression of GR6 gene in colorectal cancer and normal mucosa. METHODS: Bioinformatic software and databases were applied to analyze the characteristics of GR6 gene and putative GR6 protein. Semi-quantitative RT-PCR was used to detect the expression of GR6 gene in colorectal carcinoma, adenoma and normal mucosa. RESULT: GR6 gene, encoding putative GR6 protein, consisted of 3 exons and contained 4 CpG islands by sequence analysis. It was predicted that putative GR6 protein included one protein kinase C phosphorylation site, one casein kinase II phosphorylation site, and three N-myristoylation sites. PSORT II software analysis predicted that putative GR6 protein was located in nucleus (reliability: 76.7%). At the level of mRNA, the expression of GR6 gene was high in normal mucosa, moderate in mucosa adjacent to cancer and adenoma tissue, low in colorectal carcinoma tissue. Significant differences were demonstrated between normal mucosa and adenoma (P<0.05), normal mucosa and carcinoma (P<0.01). CONCLUSION: The putative GR6 protein, encoded by GR6 gene may predictably function as an important nuclear signal transduction molecule. Decreased expression of GR6 gene may play an important role in the initiation and promotion of colorectal neoplasia.

Amino Acid Sequence↗
PubMed1999

Differential expression of matrilysin and cyclooxygenase-2 in intestinal and colorectal neoplasms.

Both the matrix metalloproteinase matrilysin and the prostaglandin H synthase cyclooxygenase-2 (Cox-2), are thought to play key roles in colorectal carcinogenesis. These enzymes are overexpressed in 85-90% of human colorectal cancers. Furthermore, mice carrying an adenomatous polyposis coli germline mutation that are also nullizygous for either matrilysin or Cox-2 display a significant reduction in tumor multiplicity. To determine if there is a direct link between matrilysin and Cox-2, their expression was characterized in two mouse models of intestinal carcinogenesis and in human colorectal tumor samples. Both matrilysin and Cox-2 expression was increased in the mouse models and in the human colorectal cancers; however, immunohistochemistry and in situ hybridization indicated that their localization within the tumors was different. In the mouse models, Cox-2 was expressed in the superficial stroma, whereas matrilysin expression was localized exclusively to the neoplastic epithelium. In contrast, in human colorectal cancers, both Cox-2 and matrilysin were expressed in the neoplastic epithelium. Although over 80% of the specimens expressed both matrilysin and Cox-2, the levels and localization of matrilysin and Cox-2 expression were distinct. Cox-2 expression was strongest in well-differentiated areas, and matrilysin immunostaining was strongest in the more dysplastic and invasive regions of the tumor. These results indicate that these two important modulators of colorectal tumorigenesis are differentially expressed and imply that the therapeutic benefit may be improved by combination therapy utilizing selective Cox-2 and matrilysin inhibitors.

Animals↗
PubMed1994

[Assessment for development of superficial colorectal neoplasm--endoscopic and clinicopathologic analysis of 149 submucosal invasive carcinomas].

We performed the endoscopic and clinicopathologic analysis for the development of superficial colorectal carcinoma, using 149 submucosal (sm) invasive colorectal carcinomas. It was observed that superficial colorectal carcinomas had a tendency to rise by their sm massive invasion. In this study, we judged that the sm colorectal carcinomas originated from superficial colorectal carcinoma were 37 (25%) of 149 lesions, and their distribution in the colon and rectum was similar to that of advanced colorectal carcinomas, although the lesions originated from non-superficial (polypoid) colorectal carcinoma did not show so tendency. On the other hand, sm colorectal carcinomas originated from superficial colorectal carcinoma contained the evident adenomatous components in 7 (19%) of 37 lesions and had significantly higher incidence of lymph node metastasis than those originated from non-superficial (polypoid) carcinoma. These results suspected the facts as follows; 1) Superficial early colorectal carcinoma may be compatible as the origin to advanced colorectal carcinoma and has higher malignant potential than non-superficial early carcinoma. 2) Superficial colorectal carcinoma might also have the route of the development of "adenoma-carcinoma sequence", as well as "de novo" histogenesis.

Adenoma↗
PubMed1997

[Current principles of surgical treatment for early colorectal neoplasms].

A distinct correlation between tumor process expansion within the large bowel wall and dissemination has been established thus suggesting a concept of early colorectal cancer. Indications for limited surgery for early large bowel cancers are discussed. Both local excision and standard radical surgery offer practically the same advantage in cases of carcinoma located within mucosa and the submucosal layer of the intestinal wall.

Colectomy↗
PubMed1984

The use of colonoscopy in the study of synchronous colorectal neoplasms.

Over a 5-year period, 185 patients with primary colorectal carcinoma were studied by colonoscopy for synchronous neoplasms. Twenty-eight patients had incomplete examinations due to obstructing tumors, and 157 had total colonoscopy. Sixty patients (35.9%) had synchronous neoplasms, of which 43 (25.7%) were adenomatous polyps, 5 (3%) were villous polyps, and 12 (7.2%) were carcinomas. The planned surgical procedure was altered on 7 of 12 synchronous cancers (58.3%), 10 of 38 adenomatous polyps, and 17 of 157 (10.8%) patients who underwent total colonoscopy. Preoperative colonoscopy is deemed essential for the optimal management of the patient with colorectal carcinoma.

Aged↗