Decreased risk of subsequent colonic cancer in patients undergoing polypectomy after barium enema: analysis based on data from the preendoscopic era

OBJECTIVE: Published data from the Mayo Clinic gathered during the preendoscopic era were analyzed to show that the risk of subsequent colonic carcinoma is reduced in patients with benign-appearing polyps that are revealed by radiology who then undergo polypectomy. MATERIALS AND METHODS: Data from the Mayo Clinic gathered during a 6-year period before the availability of endoscopy were used to determine the effect on the subsequent risk of colonic carcinoma if the benign-appearing polyps initially revealed by radiology had been removed rather than left in place and followed up by serial barium enemas. Data were from 226 patients with benign-appearing polypoid lesions of the colon that were 1 cm in diameter or larger and had been followed up by periodic barium enemas. The period of radiologic surveillance was 12-229 months (mean, 68 months). Between two and 17 barium enemas (mean, 5.2) were performed on each patient. The clinical follow-up period was 12-242 months (mean, 140 months). RESULTS: Twenty-one adenocarcinomas developed at the site of the index polypoid lesion as found on follow-up barium enema examinations of these patients. Eleven additional adenocarcinomas of the colon were found at sites remote from that of the index lesion. If the index polyp had been removed when initially diagnosed radiologically, 66% fewer subsequent carcinomas would have occurred in these patients during the average of 11 years of clinical follow-up. CONCLUSION: Excision of benign-appearing polyps found on initial barium enema examinations would result in a significant decrease in the subsequent risk of colonic adenocarcinoma.     

Pneumocephalus and respiratory depression after accidental dural puncture during epidural analgesia--a case report

BACKGROUND: Adenomatous colonic polyps are accepted as premalignant lesions. There is controversy regarding the significance of the hyperplastic polyp. The aim of this study was to determine the incidence of further polyps in patients with only hyperplastic polyps on a first colonoscopy in comparison with patients without polyps and with adenomatous polyps. METHODS: Ninety patients had only hyperplastic polyps (group I). These patients were paired according to age and sex with subjects having no polyps (group II) and with patients having adenomas (group III). RESULTS: Fifty-six patients in group I had at least one follow-up examination. New polyps were found in 46.4% in group I versus 15.5% in group II (p < 0.001) and 50% in group III (NS). In group I, 30.7% of new polyps were hyperplastic and 69.3% were adenomas. In fact, 32.2% of group I patients developed further adenomas (mean 1.5 +/- 0.8 adenomas). These adenomas occurred 1 to 4 years after the first polypectomy (mean 2.4 +/- 0.8 years). Most of these adenomas were small and tubular, but 16.6% were villous or had severe dysplasia. CONCLUSION: Patients with hyperplastic polyps were 2.4 times more likely to have further adenomas than were those without polyps.     

Evidence for inverse agonism of SR141716A at human recombinant cannabinoid CB1 and CB2 receptors

OBJECTIVES: We studied the clinical spectrum, histology, and malignant potential of colonic polyps in Indian children (< or =12 yr). METHODS: Two hundred thirty-six children with colonic polyps were studied from January 1991 to October 1996. They were evaluated clinically and colonoscopic polypectomy was done. Children with five or more juvenile polyps were labeled as having juvenile polyposis and serial colonoscopic polypectomies were done every 3 wk. Colectomy was performed when there were intractable symptoms or clearing of the polyps by colonoscopy was not possible. Histological examination of the polyps was done. Follow-up colonoscopy was done in children with juvenile polyposis only. RESULTS: The mean age of these children was 6.12 +/- 2.7 yr, with a male preponderance (3.5:1). Rectal bleeding of a mean duration of 14 +/- 16 months was the presenting symptom in 98.7%. Solitary polyps were seen in 76%, multiple polyps in 16.5%, and juvenile polyposis in 7% (n = 17) of the children. A majority (93%) of the polyps were juvenile and 85% were rectosigmoid in location. Adenomatous changes, seen in 11%, were more common in juvenile polyposis (59%) than in juvenile polyps (5%). Among those with juvenile polyposis, colon clearance was achieved in eight, six required colectomy for intractable symptoms, and three were still on the polypectomy program. Polyps recurred in 5% of children with juvenile polyps and 37.5% of those with juvenile polyposis. CONCLUSIONS: Juvenile polyps remain the most common colonic polyps in children. A significant number of cases of polyps are multiple and proximally located, which emphasizes the need for total colonoscopy in all. Juvenile polyps should be removed even if asymptomatic because of their neoplastic potential. Colonoscopic polypectomy is effective even in juvenile polyposis. Surveillance colonoscopy is required in juvenile polyposis only.     

Clinical evaluation of fundic gland polyps and hyperplastic polyps

We performed a retrospective review of 477 cases of fundic gland polyps compared with 562 cases of hyperplastic polyps, which were detected endoscopically during the past 8 years between January, 1989 and December, 1996. All lesions were histologically confirmed by endoscopic biopsy or the examination of polypectomy specimens. Fundic gland polyps were more prevalent in middle aged-female, and were not associated with gastric adenomas and gastric cancers. These results suggested that the background mucosa of patients with fundic gland polyp was different from that of patients with hyperplastic polyp. Fundic gland polyps in 55 patients were followed up. No change was observed in the polyps of the about half subjects, the polyps of 12 cases (21.8%) decreased in size and number or resolved completely. Cases decreased in size and number or resolved completely were much more in fundic gland polyps than hyperplastic polyps. There were no malignant transformation of fundic gland polyps. We claimed that fundic gland polyps were benign and distinct from hyperplastic polyps which had a possibility of malignant transformation.     

Endoscopic polypectomy in the treatment of colonic adenomas containing adenocarcinoma

Fifty-seven adenomas containing adenocarcinoma were removed endoscopically from the colons of 56 patients (36 males and 20 females) with a mean age of 64.5 years. The 13 polyps containing carcinoma in situ were satisfactorily treated by endoscopic resection. In 29 cases, the carcinoma had invaded the head, neck or stalk of the polyp. The outcome was good in every case, including one involving invasion of the resection margin. Follow-up or intraoperative studies disclosed the presence of residual lesion in only 4 patients out of 15 with submucosal invasion. All four had invaded resection margins and incomplete endoscopic excision. Endoscopic polypectomy is a suitable therapeutic option for most colonic adenomas containing a carcinoma provided a complete resection is achieved with wide resection margins, particularly in those cases in which the submucosa is not reached.     

Colonoscopic polypectomy

The colonoscopic management of 86 patients with polypoid lesions of bleeding from the colon of intermittent nature is discussed. There were 145 polyps found in 85 of these patients. Adenomatous polyps occurring in the sigmoid colon above the reach of the standard sigmoidoscope was the most common finding and pathological diagnosis. Adenocarcinoma of the colon occurred in two patients and invasive carcinoma of a polyp was found in three other patients. Five other patients had polyps that demonstrated a carcinoma in situ. The definitive treatment of these complicated polyps is outlined. The importance of barium enema examination on follow-up of polyp and carcinoma patients and on patients with polyps found at standard sigmoidoscopy is stressed. The possibility of colonoscopic follow-up in lieu of colectomy and ileoproctostomy is suggested for patients with multiple polyps of the colon who do not belong to the familial polyposis group.     

Nasal polyps in children

The inflammatory nasal polyp is the most common benign or malignant nasal mass seen in children. Nasal polyps in the pediatric population appear to occur as inflammatory responses to bacterial infections. In 33% of the patients with polyps whom we studied, antral choanal polyps were noted, and in 20% of the patients the polyps were unilateral but not antral choanal. In 18% of the patients the polyps were bilateral and in an additional 29% they occurred bilaterally in association with cystic fibrosis. History of an allergy is infrequently associated with nasal polyps; allergies are potentially major contributing factors to nasal polyps only in patients without cystic fibrosis whose nasal polyps are bilateral. Patients with antral choanal polyps are most successfully managed by simultaneous Caldwell-Luc antrostomy and polypectomy. Sixty percent of patients with nasal polyps and cystic fibrosis are adequately managed with a single intranasal polypectomy. Simultaneous sinus surgery and polypectomy should be considered for all patients with recurrent polyps and for all patients with clinical or radiographic evidence of significant sinusitis. Complications, including epistaxis and intranasal synechia, occurred in 3% of the 170 surgical procedures performed.     

Possibility of different cancer development between the proximal and distal colon: comparison of the distribution between adenomatous polyps and cancer

BACKGROUND/AIM: The aim of this study was to compare the distribution of adenomatous polyps with that of cancer in the colon by using adenomatous polyps removed by colonoscopy. METHODOLOGY: 1223 adenomatous polyps removed by an endoscopic polypectomy were compared with 226 colon cancers with regard to their distribution, size and age. RESULTS: With patients over 65 years of age, the incidence of adenomatous polyps was lower in the proximal colon than in the distal colon, however, the incidence of cancer was higher in the proximal colon than in the distal colon (p<0.05). The distribution of adenomatous polyps according to size was also significantly different between the proximal and distal colon (p<0.05). CONCLUSION: These results thus suggest that some difference may exist in cancer development between the proximal and distal colon.     

Effects of dietary fat and a vegetable-fruit mixture on the development of intestinal neoplasia in the ApcMin mouse

The variation in colorectal cancer (CRC) incidence worldwide strongly suggests a role for dietary influences. Based on epidemiological data, protective effects of vegetables and fruit intake on CRC are widely claimed, while other data indicate a possible increased CRC risk from (higher) dietary fat intake. Therefore, we have investigated single and interactive effects of dietary fat and a vegetable-fruit mixture (VFM) in the ApcMin mouse, a mouse model for multiple intestinal neoplasia. In this study, four different diets (A-D) were compared, which were either low in fat (20% energy diets A/B) or high in fat (40% energy diets C/D). In addition, 19.5% (wt/wt) of the carbohydrates in diets B and D were replaced by a freeze-dried VFM. The diets were balanced so that they only differed among each other in fat/carbohydrate content and the presence of specific plant-constituents. Because the initiation of intestinal tumors in ApcMin mice occurs relatively early in life, exposure to the diets was started in utero. Without the addition of VFM, mice maintained at a high-fat diet did not develop significantly higher numbers of small or large intestinal adenomas than mice maintained at a low-fat diet. VFM added to a low-fat diet significantly lowered multiplicity of small intestinal polyps (from 16.2 to 10.2/mouse, 15 animals/group), but not of colon tumors in male ApcMin mice only. Strikingly, addition of VFM to female mice maintained on a low-fat diet and to both sexes maintained on a high-fat diet significantly enhanced intestinal polyp multiplicity (from 16.5 to 26.7 polyps/mouse). In conclusion, our results indicate that neither a lower fat intake nor consumption of VFM included in a high-fat diet decreases the development of polyps in mice genetically predisposed to intestinal tumor development.     

AIDS complicated with disseminated toxoplasmosis: a pathological study of 9 autopsy cases

BACKGROUND: In addition to identifying and eradicating premalignant lesions, and detecting early cancer before the development of life-threatening consequences, new concepts and technological advances have stimulated a hightened interest in the secondary prevention of colorectal cancer. METHODS: People whose first degree relatives have had colorectal cancer are considered to run a higher risk of developing colorectal carcinoma. A screening program was carried out for 358 first degree relatives of colorectal cancer patients using colonoscopic screening. RESULTS: The mean age of these first degree relatives was 44 years, ranging from 13 to 78 years. Two hundred and eleven (58.9%) of them were asymptomatic. Totally 73 polyps were detected in 53 subjects (14.9%). Two cancer lesions were identified. Thirty polyps (41.1%) measured between 0.5 cm and 2.0 cm. The polyps were mostly located in the rectum and sigmoid colon (63%). One polyp was found in a subject below 30 years of age. Over the age of 30, the incidence of polyp increased dramatically. CONCLUSIONS: Our results confirmed that the screening program for the first degree relatives of patients with colorectal cancer is worthwhile. The program would have a more significant impact if the screening could start from subjects around the age of 30.     

Long pedunculated colonic polyp composed of mucosa and submucosa: proposal of a new entity, colonic muco-submucosal elongated polyp

We encountered 15 patients with colonic polyps showing histologic features that did not belong to any of the known categories. All polyps were elongated and drumstick-shaped, with lengths of 12 to 160 (mean, 29 mm) mm. Histologically, the polyps were covered with normal mucosa and consisted of edematous, loose, fibrous, connective tissues and dense, fibrous submucosal layers, often showing dilation of blood vessels and lymphatics. Although the mechanism of generation of such polyps remains unknown, their elongation may be caused by intestinal motion. Because this kind of polyp has not been described previously outside Japan, we here introduce a new type of polyp, which we have proposed calling the colonic muco-submucosal elongated polyp.     

A normal initial colonoscopy after age 50 does not predict a polyp-free status for life

OBJECTIVES: The prevalence of colon polyps increases with age in the general population. It is unknown whether a lack of adenomatous polyps determined at one time point after the age of 50 is predictive of a subsequent low risk of polyp development. METHODS: Twenty-nine patients between ages 50 and 70 who had no prior history of polyps and had a normal colonoscopy at least 5 yr previously were recruited for follow-up colonoscopy to evaluate the incidence of neoplastic disease in this presumably low-risk group. RESULTS: The incidence of adenomatous polyps after a mean of 5.74 yr was 41.4% (95% confidence interval: 23.5-61.1%). A total of 20 adenomatous polyps were found in 12 patients. Seven polyps were 5 mm or more in size. CONCLUSIONS: We conclude that in patients with no history of colonic neoplasia who are 50 yr old, or older, the finding of a normal colonoscopy does not predict diminished risk of neoplasia.     

Juvenile polyps in childhood

61 children, from 12 months to 14 years old with colonic juvenile polyps were studied using double contrast radiology and conventional and fiber optic endoscopy. In all cases the tumor excision was performed without fulguration. 43 polyps were located within the rectal area and 17 in the colon. In one patient 4 polyps were found at different place in the colon. In 90 percent of the cases the symptom was fecal blood loss and spontaneous merging of the tumor across the anus in the remaining 10 percent. Histologic examination showed no atypic cell.     

Response to Weisz''s and Kappauf''s critiques of the Temple longitudinal study

Because of rapid technological advances in endoscopic instrumentation, electrosurgical polypectomy and electrocoagulation has become a reality in the upper gastrointestinal tract. Twenty gastric polyps and three duodenal polyps have been removed. Six additional hyperplastic gastric polyps were electrodesiccated. Nine gastric ulcers, four duodenal ulcers, one hemorrhagic gastritis, one gastric varix and three Mallory-Weiss tears were successfully electrocoagulated. One duodenal ulcer and one Mallory-Weiss tear was unsuccessfully electrocoagulated. No morbidity nor mortality occurred as a result of electrosurgical polypectomy or electrocoagulation.     

The genomic organization of the genes for human lipopolysaccharide binding protein (LBP) and bactericidal permeability increasing protein (BPI) is highly conserved

PURPOSE: The authors evaluated computed tomographic (CT) virtual colography for the detection of simulated polyps under ideal conditions, as well as the effects on lesion conspicuity of (a) collimation, (b) table pitch, and (c) orientation of the colon lumen with respect to the gantry. MATERIALS AND METHODS: Pig colon was resected and cleansed, and polyps with diameters of 3, 7, and 10 mm were created. Each specimen was scanned with collimation of 5 and 7 mm and table pitch of 1.0, 1.6, and 2.0 at angles of 0 degrees, 45 degrees, and 90 degrees to the gantry. The initial two-dimensional (2D) images were reconstructed at 1-mm intervals (2D reconstructions), from which three-dimensional (3D) virtual colography images were generated. Polyp conspicuity on the initial and reconstructed 2D images and the 3D reconstructions was evaluated on a three-point scale: 0 = polyp not depicted, 1 = polyp faintly depicted, and 2 = polyp clearly depicted. RESULTS: The 10-mm-diameter polyp was clearly depicted (grade 2 conspicuity) on every initial and reconstructed 2D image and 3D reconstruction without regard to collimation, table pitch, or angle to the gantry. The 7-mm-diameter polyp was clearly depicted (grade 2 conspicuity) on every initial and reconstructed 2D image, but conspicuity on 3D reconstructions varied as the imaging parameters varied. The 3-mm-diameter polyp was faintly depicted (grade 1 conspicuity) on the initial and reconstructed 2D images and 3D reconstructions, but conspicuity varied on the 3D reconstructions as the imaging parameters varied. CONCLUSION: CT virtual colography helped detection of small mucosal polyps regardless of the angle of the colon lumen to the gantry at which they were obtained.     

Co-expression of polyhydroxyalkanoate synthase and (R)-enoyl-CoA hydratase genes of Aeromonas caviae establishes copolyester biosynthesis pathway in Escherichia coli

Arylamine N-acetyltransferase 2 (NAT2) is involved in both the detoxification and bioactivation of carcinogenic arylamines and other mutagens. This enzyme is polymorphic, and the fast and slow phenotypes are thought to be risk factors for colon and bladder cancer, respectively. Here, we report on a case-control study of adenomatous and hyperplastic polyps, with particular attention to tobacco smoking, a known risk factor for adenomas, and polymorphisms of NAT2. All participants underwent complete colonoscopy and were subsequently divided into case and control groups on the basis of pathology. Cases were diagnosed with confirmed adenomas (n = 527) or hyperplastic polyps (n = 200); controls (n = 633) had no history of colonic neoplasia and no polyps at colonoscopy. NAT2 genotype was determined using an oligonucleotide ligation assay and fast, intermediate, or slow phenotype imputed. Multivariate-adjusted odds ratios (ORs) and 95% confidence intervals were computed using logistic regression adjusting for age, sex, nonsteroidal anti-inflammatory drug use, and hormone replacement therapy use. Smoking was associated with an increased risk of adenomas [current versus never smoking OR = 2.0 (95% confidence interval, 1.4-2.9)] and hyperplastic polyps [current versus never smoking OR = 4.1 (2.6-6.5)]. NAT2 status among adenomatous polyp patients and hyperplastic polyp patients, respectively, showed ORs of 1.1 (0.8-1.4) and 1.2 (0.8-1.6; intermediate versus slow) and 1.1 (0.6-1.9) and 0.9 (0.4-1.9; fast versus slow). There were no differences in risk when adenoma patients were stratified on multiplicity, size, or histopathological subtype of polyps. Never-smokers showed no variation in risk across acetylator status for either species of polyp, whereas current smokers showed ORs of 2.0 (1.2-3.2) and 2.3 (1.4-3.9) for adenomas and 3.9 (2.1-7.1) and 4.9 (2.6-9.4) for hyperplastic polyps for slow and intermediate/fast NAT2, respectively, compared with slow-NAT2 never-smokers. Risks of both multiple [OR = 4.3 (2.1-8.8)] and large [OR = 3.8 (1.9-7.5)] adenomas were somewhat elevated in current smokers with an intermediate/fast phenotype compared with smokers with a slow NAT2 phenotype, but the interaction was not statistically significant. Risk of hyperplastic polyps and adenomatous polyps is strongly related to smoking. There is little suggestion of interaction between NAT2 status and smoking and no relationship with NAT2 genotype alone.     

Primary colon cancer without gross mucosal tumor: unusual presentation of a common malignancy

Colon cancer typically arises in the colonic lumen, allowing for endoscopic detection of cancerous and premalignant lesions. In the case presented, a 73-year-old man with iron deficiency anemia had two colonoscopies showing only diverticula and internal hemorrhoids. Three years later, when the patient complained of dull, intermittent lower abdominal pain, a third colonoscopy identified diverticula, three adenomatous polyps, and no other abnormality. Computed tomography (CT) of the abdomen revealed a 5 cm x 6 cm pericolic fluid collection, which was later found to communicate with the sigmoid colon. The surgical specimen from a partial colectomy contained a distal sigmoid perforation with a 2.5 cm moderately differentiated adenocarcinoma in the underlying submucosal tissue. There was no gross intraluminal tumor. Histopathology, including immunohistochemistry, was consistent with colonic adenocarcinoma. Primary colon cancer grossly sparing the mucosa is an unusual presentation for this common malignancy.     

A prospective evaluation of the safety and efficacy of methohexital in the emergency department

OBJECTIVE: Knowledge of a possible correlation between distal polyps found at screening sigmoidoscopy and proximal colonic lesions is important for deciding whether to perform total colonoscopy or not. PATIENTS: A prospective analysis of 2439 consecutive patients with colorectal polyps. Of these, 304 were asymptomatic subjects who underwent complete colonoscopy for screening and were found to have adenomatous or hyperplastic polyps in the distal colorectum. RESULTS: Ten (15%) out of 65 patients with distal hyperplastic polyps only and 86 (36%) out of 239 with distal adenomatous polyps were found to have adenomatous polyps in the proximal colon as well (P < 0.001). The frequency of synchronous proximal adenomas in patients with small (< or = 5 mm) or large distal adenomas (> 5 mm) was comparable (37% and 35%, respectively). However, patients with small distal adenomas had significantly smaller proximal adenomas (P = 0.004) containing less villous component (P = 0.017) than those with large distal adenomas. Neither the patient's age nor the presence of multiple distal adenomas increased the prevalence of proximal adenomas. CONCLUSION: Hyperplastic polyps found on rectosigmoidoscopy do not indicate a need for a complete colorectal examination, as 15% of patients with distal hyperplastic polyps will have proximal adenomatous polyps, a figure that is comparable with that of asymptomatic patients having no distal polyps, either hyperplastic or adenomatous. When only small distal adenomas are found at screening sigmoidoscopy in asymptomatic persons the decision to do a total colonoscopy should be based on individual considerations, as in such cases only small polyps are to be expected in the proximal colon.