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PubMed1988

Effects of cumene hydroperoxide on adenosine diphosphate ribosyl transferase in mononuclear leukocytes of patients with adenomatous polyps in the colon.

We have studied the effects of plasma and of cumene hydroperoxide (CUM) on adenosine diphosphate ribosyl transferase (ADPRT) from mononuclear leukocytes (HML) of patients with colonic adenomatous polyps (n = 22), with colonic hyperplastic polyps (n = 5) and with neither type of polyp (controls) (n = 6). ADPRT was measured after incubation of HML with plasma alone (termed the plasma value), and with plasma plus CUM (50 microM) (the activated value); the difference elicited by CUM was termed the induced value. There was no significant difference in values between the control and hyperplastic polyp groups: these were combined for further analysis. The plasma (P = 0.038), activated (P = 0.009) and induced (P = 0.0024) values of the combined group all differed significantly from those of the adenoma group. At low exposures, CUM stimulated both ADPRT and unscheduled DNA synthesis and, at higher exposures, inactivated both. Pretreatment of HML with vitamin E protected against these effects of CUM, while pretreatment with diamide (which depletes GSH) accentuated the effects. This study demonstrates a differential reaction of ADPRT in patients harboring colonic adenomas and suggests that the origin of this difference may lie in cellular responses to oxidative stress.

Benzene Derivatives↗
PubMed1998

[Inflammatory fibroid polyps of the colon].

Inflammatory fibroid polyp is an uncommon lesion involving the stomach, the small bowel and occasionally the colon. Inflammatory fibroid polyp is a large polypoid lesion arising from the submucosa. It has no malignant potential although extensive infiltration may occur. The main histological characteristics are diffuse inflammatory infiltrate with eosinophils and highly vascularized fibrocytic stroma. Immunohistochemistry is always positive for vimentine and negative for S 100 and desmin. We report four cases of inflammatory fibroid polyps, 3 of which mimicked carcinoma of the colon. Exploratory laparotomy and histopathological examination of the resected specimen were necessary to confirm definitive diagnosis. In the last case, diagnosis was established by histological examination of an endoscopically-removed colonic polyp.

Aged↗
PubMed1995

Accumulation of beta-carotene in normal colorectal mucosa and colonic neoplastic lesions in humans.

The quantity of beta-carotene (BC) accumulated in colonic polyps and colonic cancerous tissue in humans in situ was determined relative to the quantity accumulated in normal colon and rectal tissue. Serum concentration of BC, retinol, and alpha-tocopherol and tissue BC concentration were determined by high-performance liquid chromatography in samples obtained before and after oral supplementation with BC (30 mg/day). The serum BC and retinol concentrations significantly increased in response to supplementation in control, polyp, and cancer patients, but there was no change in serum alpha-tocopherol concentration. The BC concentration in tissue (colon, rectum, and tumor) of cancer patients was significantly less than that in tissue samples from control and polyp patients. Relative to baseline values, BC accumulated to a significant extent in tissues from all patients, including polyp and tumor tissue, during supplementation. The results indicate that BC does accumulate in colonic neoplastic tissue in humans and may potentially be utilized to augment cytotoxicity of chemotherapeutics or to prevent malignant transformation of cells.

Adenomatous Polyps↗
PubMed2006

Colonoscopic polypectomy in retroflexion.

BACKGROUND: Little has been written about the value of retroflexion in the removal of large sessile colon polyps. OBJECTIVE: The objective of the study was to evaluate the utility of retroflexion for removal of large sessile colon polyps. DESIGN: This was a retrospective evaluation of consecutive cases. SETTING: This study was conducted at an academic-hospital-based tertiary-referral colonoscopy practice. PATIENTS: The study comprised consecutive patients with sessile polyps > or = 2 cm who were undergoing endoscopic resection. INTERVENTIONS: The intervention was endoscopic resection of 59 consecutive sessile colon polyps 2 cm or larger in size and located proximal to the rectum by using prototype colonoscopes with short bending sections. MAIN OUTCOME MEASURES: The main outcome measurement was successful endoscopic resection. RESULTS: Fourteen of the polyps were removed either entirely (n = 4) or partially (n = 10) in retroflexion. Patients with polyps that were removed in retroflexion were more likely to have been referred by another colonoscopist than those patients with polyps removed entirely in the forward view (p = 0.05). There were no perforations and no complications related to retroflexion. LIMITATIONS: The study is retrospective, and the practice is a tertiary referral colonoscopy practice. The colonoscopes used are not widely available at this time. CONCLUSIONS: Retroflexion is a useful adjunctive procedure for the removal of some colon polyps proximal to the rectum that are difficult to access endoscopically. The use of retroflexion can increase the fraction of proximal sessile colon polyps amenable to endoscopic resection.

Colonic Polyps↗
PubMed1993

Effects of vitamin antioxidant supplementation on cell kinetics of patients with adenomatous polyps.

Colonic crypt cell proliferation is used as an indicator of risk of colorectal carcinoma. Subjects with adenomatous polyps and cancer have an increased cell proliferation and a shift of the proliferative zone towards the apex of the crypt. Epidemiological and in vitro studies have confirmed a link between vitamins A, E, C, beta-carotene, and colorectal cancer. In vitro bromodeoxyuridine immunohistochemical technique was used to assess the effect of daily oral supplementation with vitamin E (160 mg), vitamin C (750 mg), or beta-carotene (9 mg) on the colonic crypt cell proliferation in patients with adenomatous polyps (n = 40) compared with normal subjects with no colonic disease (n = 20). The patients were given supplementation for one month and colonic biopsy specimens were taken before and at the end of the trial. Patients with adenomatous polyps had a significantly higher mean labelling index per cent than controls (p < 0.001). Vitamin C or beta-carotene supplementation, however, significantly reduced the total proliferation (p < 0.005) whereas vitamin E supplementation had no effect on the colonic crypt cell proliferation. beta-carotene reduced cell proliferation at the base of the crypt only. Vitamin C reduced cell proliferation in all the crypt compartments from the apex to the base to those values seen in age and sex matched controls. These findings indicate that prolonged supplementation with vitamin C may reduce the recurrence of adenomatous polyps.

Adenoma↗
PubMed1993

Hyperplastic polyp and colonic neoplasia. Is there an association?

Hyperplastic polyps are regarded as non-neoplastic lesions with no malignant potential. However, several case reports and a clustering phenomenon suggest that they may arise in abnormal colonic that is predisposed to develop neoplastic lesions. The hyperplastic polyp also displays markers associated with colorectal cancer. In addition, several recent articles have addressed the question of hyperplastic polyp in the distal colon as a marker of more proximal adenomatous polyp. Many endoscopists discovering a distal hyperplastic polyp will wish to ensure the absence of a proximal neoplastic lesion.

Colonic Neoplasms↗
PubMed1989

Is there an association between gastric polyps and colonic neoplasms?

The association between colonic neoplasms and gastric polyps (GP) was evaluated. Two hundred and sixty patients with known colonic neoplasms undergoing gastroduodenoscopy for abdominal symptoms, with or without anemia, were evaluated for the occurrence of synchronous GP. There were 100 patients with 1-4 colonic adenomas, 80 patients with multiple (5 or more) colonic adenomas and 80 patients with colorectal cancer. One hundred patients free from colonic neoplasms, investigated for abdominal pain or anemia, served as controls. The overall occurrence of GP in patients with colonic neoplasms was 18.8% compared to 1% in the control group. Hyperplastic GP were found in 4, 22.5, 18.7 and 1% of these patients, respectively, while gastric adenomas occurred in 2, 3.7, 3.5 and 0%, respectively. Patients with colorectal cancer or multiple colonic adenomas had significantly more GP than patients with 0-4 colonic adenomas. It is suggested that gastroduodenoscopic evaluation should be performed in patients with colorectal cancer or with 5 or more colonic adenomas.

Adenoma↗
PubMed2002

Telomere length changes in colorectal cancers and polyps.

Telomere shortening and telomerase activation occur frequently in cases of colorectal carcinoma. In this study, we correlated the clinicopathological parameters with the telomere length in colorectal carcinomas, colonic polyps, and normal colonic tissues. We also investigated whether the telomere length changes reflect the biologic behavior of tumors and different modes of tumor development. Telomere length was determined by terminal restriction fragment Southern blot analysis in 20 invasive colorectal carcinomas and normal mucosa from the same patients. We also examined 20 colonic polyps and associated normal mucosa. Telomere shortening was detected in 16/20 (80%), and telomere elongation in 2/20 (10%) cases of colorectal carcinoma, and no changes in 2 subjects. In the colonic polyp patients, shortening was detected in 4/20 (20%), elongation in 6/20 (30%), and no change in 10/20 (50%). The frequency of telomere shortening was significantly different between colorectal carcinoma and polyp groups. Decreased telomere length was noted in 92.9% (13/14) of Dukes' C and 50% (3/6) of Dukes' B. The difference between these two sub-groups was statistically significant. This study suggests that the telomere length in colorectal carcinomas is decreased upon the development of malignancy. A significant difference in telomere length between polyps and invasive colorectal carcinomas may reflect a different biologic behavior of colorectal carcinomas.

Adult↗
PubMed1998

Is laparoscopic resection of colorectal polyps beneficial?

BACKGROUND: We set out to compare the results of laparoscopic and open resections of colorectal polyps. METHODS: Forty-five consecutive patients who underwent operation by a single surgeon for endoscopically irretrievable colonic polyps between April 1992 and March 1996 were classified into the following two groups: group I, laparoscopic procedures for colonic polyps (n = 23); and group II, open procedures for colonic polyps (n = 22). RESULTS: No significant differences were seen between the groups relative to age [71.7 +/- 10.7 versus 70.6 +/- 13.7 years], gender [male:female = 10:13 versus 13:9], history of previous abdominal operation (eight of 23 [34.8%] versus 10 of 22 [45.5%]), type of pathology (villous: seven of 23 [30.4%] versus four of 22 [18.1%], tubulovillous: nine of 23 [39.1%] versus six of 22 [27.2%], tubular: three of 23 [13.0%] versus seven of 22 [31.8%]), size of polyps (2.6 +/- 1.7 cm versus 2.7 +/- 1.5 cm), or type of procedures (right hemicolectomy: 15 of 23 [65.2%] versus 11 of 22 [50%], sigmoid colectomy: five of 23 [21.7%] versus six of 22 [27.3%], left hemicolectomy: two of 23 [8.7%] versus two of 22 [9.1%]). There was no mortality and no difference in the incidence of postoperative complications (four of 23 [17.4%] versus seven of 22 [31.8%]), blood loss (167 cc versus 243 cc), number of retrieved lymph nodes (7.1 +/- 5 versus 6.6 +/- 4), incidence of carcinoma in polyps (two of 23 [13.0%] versus four of 22 [18.2%]), or medical cost ($22,840 versus $18,420), respectively, between the two groups. There were statistically significant differences in length of ileus (3.5 +/- 1.0 days versus 5.5 +/- 1.8 days), postoperative pain (2.3 +/- 1.4 versus 3.7 +/- 1.9 on postoperative day 1 [patient pain rating scale 1-10]), length of hospital stay (6. 5 +/- 2.0 days versus 9.4 +/- 2.7 days), and return to normal activity (5.2 +/- 4.2 weeks versus 9.3 +/- 12.1 weeks) in group I compared to group II, respectively. However, patients in group II had a longer mean specimen length (18.5 +/- 6.4 cm versus 29.1 +/- 22.7 cm) and a shorter mean operative time (177.6 +/- 52.7 min versus 143 +/- 51.4 min) than patients in group I. CONCLUSIONS: Laparoscopic colectomy for colonic polyps has definite advantages over traditional open surgery, including less postoperative pain, earlier return of bowel function, and earlier return to normal activity. Conversely, its disadvantages include longer operative time and a shorter specimen.

Aged↗
PubMed1993

Morphometric analysis of colonic adenomatous polyps.

Morphometric evaluation of adenomas of the colon to determine their degree of dysplasia is still controversial, since subjective factors influence the decision concerning benignancy or malignancy. Some indices have been proposed to assist in categorizing intermediate lesions into benign or malignant. However, these indices show a wide range of distribution. To evaluate the reliability of one such index, the index of structural atypism (ISA, area of glands/area of stroma), we studied polyps as a whole, and found great variability of index values within a single polyp.

Colonic Polyps↗
PubMed2001

[Nested case-control study on the risk factors of colorectal cancer].

OBJECTIVE: To investigate the risk factors of colorectal cancer. METHODS: A nested case-control study was conducted based on a cohort of 64,693 subjects in Jiashan county, Zhejiang, China. One hundred and ninety-six cases of colorectal cancer were detected during a follow-up program for 10 years. Nine hundred and eighty non-colorectal cancer subjects were randomly selected from the cohort as controls. Univariate analysis and mutivariate non-conditional logistic regression were used to analyse associations between the exposure factors and colorectal cancer. RESULTS: The age of case group was significantly older than that of the control group. Moreover, the age at diagnose of colon cancer was significantly older than that of the rectal cancer. Other than age, the final regression model showed that mucous blood stool history and colon polyp history were significantly associated with colon cancer (OR = 2.961, 95% CI:1.202-7.298 and 8.941, 95% CI:1.820-43.926, respectively) while mixed sources of drinking water was found to be associated with rectal cancer with a OR value of 1.823 (95% CI:1.024-3.247). CONCLUSION: The risk factors of colon cancer were different from that of the rectal cancer. Age was an important factor influencing the incidence of both colon cancer and rectal cancer. Mucous blood stool history and colon polyp history were associated with colon cancer, while drinking mixed water was closely associated with rectal cancer.

Adult↗
PubMedDate not supplied

Polyps in a low-risk colonic cancer population in Colombia, South America.

Colonic polyps were systematically searched for in 508 specimens collected from unselected autopsies in individuals more than 10 years of age from Medellín, Colombia, a low-incidence geographic region for colorectal cancer. Adenomatous polyps have a low prevalence rate in both sexes, comparable to that found in Cali, Colombia and other populations with low risk for cancer. They were found more frequently in the right side of the colon and are rare in the sigmoid colon. They begin to appear in the third decade of life in both sexes. Prevalence rates for single and multiple polyps increase with age in both sexes, males showing higher rates than females at every age group. Adenomatous polyps in this population are usually less than 3 mm in diameter and do not show villous changes or epithelial atypia. Hyperplastic polyps were more frequently observed than adenomatous polyps and rates show a progressive increase with age in both sexes. Multiplicity also increases with age. Most polyps are located in the low rectum and sigmoid followed by the cecum and ascending colon. Usually hyperplastic polyps are smaller than 3 mm in diameter and do not show epithelial atypia. Juvenile polyps were infrequently found in this series because children less than 10 years old were excluded. Diverticular disease was also rare and, when found, was not associated with adenomatous polyps. The association between adenomatous polyps and colonic cancer is discussed based on findings in this report.

Adolescent↗
PubMed1989

Expression of the ErbA-beta class of thyroid hormone receptors is selectively lost in human colon carcinoma.

Members of the erbA gene family are involved both in control of differentiation and in neoplasia. V-erbA, a retroviral oncogene, blocks avian erythroid differentiation. V-erbA-related transcripts are physiologically expressed in multiple normal tissues. They encode a family of transcriptional regulatory factors, some of which are thyroid hormone receptors. In man, two genes, erbA-alpha and erbA-beta, are transcriptionally active. We examined expression of erbA-related transcripts in normal and neoplastic colon. In normal colon mucosa, as well as in a colon polyp and in a colon polyp cell line, three characteristic erbA-related transcripts were consistently found. One transcript of 6 kb was erbA-beta related. Two transcripts of 2.7 and 5.2 kb were erbA-alpha related. In eight patients' colon carcinomas expression of the 6-kb erbA-beta transcript was absent or markedly diminished when compared with the same patients' noninvolved mucosa. In contrast, expression of the two erbA-alpha transcripts was the same in both colon carcinoma and noninvolved mucosa. No evidence was found of erbA-beta gene deletion in any of the tumors lacking erbA-beta expression. These data suggest that selective loss of normally present erbA-beta gene expression accompanies malignant transformation of the colonic epithelial cell.

Cell Line↗
PubMed1996

Altered mucin core peptide immunoreactivity in the colon polyp-carcinoma sequence.

Altered mucin glycosylation occurs in colonic adenomas and can correlate with risk for malignant transformation. The purpose of this study was to determine if immunoreactivity of core tandem repeat peptides of specific mucin genes correlates with histopathologic criteria of malignant potential in the colon. Expression of MUC1, MUC2, and MUC3 core tandem repeat proteins was examined in specimens of normal mucosa (n = 20), hyperplastic polyps (n = 10), adenomatous polyps (n = 89), and invasive cancer (n = 19). An immunohistochemical scoring system that takes into account specimen heterogeneity and yields an integrated numerical score subject to statistical analysis was used. RNA message levels from tubular and tubulovillous adenomas (n = 13), normal colon (n = 12), and moderately differentiated adenocarcinomas (n = 8) were determined using RNA slot blot analysis with mucin-specific cDNA probes. MUC1 staining was rarely present in normal colon. MUC2 immunoreactivity was limited to goblet cells in most normal colonic crypts, and MUC3 staining was weakly expressed in the upper crypt regions only. In comparison with normal and hyperplastic specimens, MUC1 and MUC3 immunoreactivity scores were significantly increased in adenomas of increasing villous histology, size, and dysplasia. MUC2 scores were significantly increased in adenomas of greater villous histology and size. Comparable MUC1, MUC2, and MUC3 mRNA levels were present in adenomas and normal colon, whereas mucin mRNA levels were decreased in adenocarcinomas. We conclude that enhanced immunoreactivity of MUC1, MUC2 and MUC3 mucin tandem repeats occurs in adenomatous polyps and is associated with an increased risk for malignant transformation.

Adenoma, Villous↗
PubMed2004

Analysis of reciprocal congenic lines reveals the C3H/HeJ genome to be highly resistant to ApcMin intestinal tumorigenesis.

Genetic background affects polyp development in the Multiple intestinal neoplasia (Apc(Min)) mouse model. The Modifier of Min 1 (Mom1) locus accounts for approximately 50% of the variation in polyp multiplicity. We generated reciprocal congenic lines, such that the recipient C57BL/6J (B6) strain carries a donor C3H/HeJ (C3H) Mom1 allele, and the recipient C3H strain carries a donor B6 Mom1 allele. Hybrid progeny from congenic females mated to B6 Apc(Min/+) males were analyzed. A single C3H Mom1 locus on the B6 background reduced small intestinal polyp numbers by 50% and colon polyp incidence by 66% compared to their susceptible B6 Mom1(S/S)Apc(Min/+) siblings. These findings show that the C3H genome contains a resistant Mom1(R) locus. The reciprocal congenic line, which carries the susceptible B6 Mom1(S) locus on the C3H background, reduced small intestinal polyp numbers by 80% and colon polyp incidence by 95% compared to B6 Mom1(S/S)Apc(Min/+) mice. These data demonstrate that unidentified modifiers in the C3H strain can suppress intestinal polyp multiplicity in Apc(Min/+) mice, and act in the absence of a resistant Mom1(R) locus.

Adenomatous Polyposis Coli↗