[Colorectal polyps and cancers by sub-site: epidemiologic findings in Geneva and Vaud]

The present study is a comparative analysis of the adenomatous polyps and colorectal cancers, registered during a determined period within the population of the cantons of Geneva and Vaud. The analysis is particularly based on the polyp/cancer ratio by sub-site. Histological type as well as age and sex of the patient are taken into consideration.

Epidemiology of polyps in the rectum and sigmoid colon. Evaluation of breath methane and predisposition for colorectal neoplasia

The clinical significance of methanogenic bacteria in large-bowel carcinogenesis has not been established so far. As part of a screening study of a randomized population sample of 200 men and 200 women aged 50-59 years, the present breath methane study was designed to gain further information on methane excretion in relation to premalignant colorectal lesions, familial cancer disposition, and dietary fat and fiber. Testing for breath methane excretion did not contribute towards the identification of individuals with premalignant colorectal lesions and therefore should probably not be considered a screening tool.

The incidence and prevalence of familial polyposis coli in Denmark

Based on the Danish Polyposis Register, the frequency of familial polyposis coli was estimated at the end of 1982. The mean annual incidence rate of polyposis coli has remained rather constant at approximately 1 X 10(-6) X yr-1 since the forties. The life-time risk of developing polyposis coli is about 1 X 10(-4). The point prevalence rate was 26 X 10(-6) at the end of 1982. The number of cases found in sibs and children of probands made it probable that a nation-wide prophylactic examination of first degree relatives resulted in a complete identification of affected family members. The completeness of the Danish Polyposis Register in the period 1976-82 was estimated to be 90% and the validity of the diagnosis is considered to be 100%.

Epidemiology of polyps in the rectum and sigmoid colon. Evaluation of nutritional factors

Epidemiological studies have suggested an association between diet and colorectal cancer. Case/control studies, however, have been scarce, and studies based on interview with cancer patients who have symptoms from their cancer are inevitably prone to bias. An endoscopic population screening study for detection of colorectal adenomas enabled a double-blind registration of diet during 5 consecutive weekdays. Neither the participant nor the dietitian was informed of the findings at endoscopy. The estimation of 23 nutritional components was based on analysis of local commercial food and on the composition of foods in Norway. Results showed increasing consumption of fat and decreasing consumption of fiber and cruciferous vegetables in the presence of increasing neoplastic changes. The present material will form the basis for dietary-related follow-up studies.

Epidemiology of polyps in the rectum and sigmoid colon. Size, enzyme levels, DNA distributions, and nuclear diameter in polyps of the large intestine

Enzyme activity and cell cycle variables were measured in 38 adenomas and 9 hyperplastic large-intestinal polyps equal to or larger than 5 mm in diameter. The polyps were resected endoscopically from patients 50-59 years old. A significantly higher activity of lactate dehydrogenase (LD) was found in polyps from women than in those from men. A higher LD and activity was also observed in adenomas with moderate to severe dysplasia than in those with mild dysplasia. A significantly higher activity was found for LD and glucose-6-phosphate dehydrogenase (G6PD) in adenomas greater than or equal to 10 mm than in adenomas less than 10 mm in diameter. DNA flow cytometry showed that all hyperplastic polyps were diploid and that two of the adenomas had an aneuploid DNA stemline in addition to the diploid one. The S-phase fraction varied from 3.5% to 26.5% and the G2 fraction from 0.4% to 6.7%. Two overlapping populations were found, based on nuclear size measurements. Hyperplastic polyps had almost only small nuclei, whereas adenomas had both small and large nuclei in various ratios. No statistical correlations were found between the S-phase or G2-phase fractions and polyp size or the presence of dysplasia. The number of adenomas with aneuploidy was too small to disclose a relationship to polyp size or enzyme activity. The increased enzyme activity in larger polyps and in polyps from women may point to certain risk factors in these special groups. The results indicate a further need for studies of combination of markers for prognostic evaluation of large-intestinal adenomas.

Extracolonic polyps in familial polyposis coli and Gardner's syndrome

Endoscopy and biopsy of the upper gastrointestinal tract and terminal ileum were performed in 24 patients with familial polyposis or Gardner's syndrome in order to further define the incidence of extracolonic adenomatous polyps. Polyps, usually multiple and small in size, were detected in the gastric fundus (12.5 percent), antrum (29.1 percent), duodenum (66.6 percent), and terminal ileum (41.7 percent). Histology showed hyperplasia of the fundic glands and cystic dilatation in the polyps of gastric fundus, and adenomas in several cases of antral (three patients) or duodenal polyps (14 patients). Polyps of the terminal ileum were either adenomas (five patients) or lymphoid aggregates. Patients with stigmata of Gardner's syndrome, desmoids or mesenteric fibromatosis presented a major incidence of adenomas in the duodenum, but not in other parts of the digestive tract investigated. Subsequent checkup after an average of 33 months in ten patients revealed an increase of lesions only in the duodenum in two patients. These findings confirm that adenomatous polyps are not limited to the colon and rectum, as previously believed, but can affect the whole gastrointestinal tract. Periodic surveillance of mucosa seems to be indicated, especially for the duodenum, since degeneration of adenomas into carcinoma is possible.

Prevalence of polyps in an autopsy series from areas with varying incidence of large-bowel cancer

The results of this multicentre autopsy study emphasize the relationship between the prevalence of adenomas and the incidence of large-bowel cancer. The highest proportion of autopsies with adenomas was observed in the area with the highest incidence of large-bowel cancer. The segmental distribution of adenomas within the colon was found to be similar to the site distribution of cancer. However, the lowest proportion of adenomas was found in the rectum, the segment in which cancer is most frequent. The latter finding suggests that either the adenoma-carcinoma sequence is a less important pathway in the pathogenesis of rectal cancer, or that more rectal than colonic adenomas become malignant. The high proportion of hyperplastic polyps in the rectum, and statistically significant regional differences following the same patterns as the incidence of rectal cancer suggest that there could be at least an indirect relationship between hyperplastic polyps and cancer of the rectum. Adenomas of both colon and rectum were more frequent in men than in women, contrary to findings with colon cancer. However, as for colon cancer, the sex ratio of adenomas changed with age, from slightly below unity in persons under 65, to above unity for those aged 65 and over. A major difficulty that emerged was the histological identification of "polyps" because of the degree of autolysis of epithelial cells in the mucous membrane, and this difficulty largely contributed to the poor consistency of histological reporting. Regular consistency surveys of histological preparations should be recommended in any type of multicentre study in which histological examination is included.

Epidemiology of polyps in the rectum and sigmoid colon. Histological examination of resected polyps

In an endoscopic screening study of rectosigmoidal polyps in a defined normal population aged 50-59 years, polyps 5 mm or larger in diameter were removed by diathermic snare resection for histological examination. Histological examination was possible in 50 of 55 polyps removed during colonoscopy from 27 men and 17 women. Of these polyps 41 (82%) were adenomas--12 with moderate dysplasia, 1 with severe dysplasia, and 2 with intramucosal carcinoma. In addition, a small ulcerating carcinoma, Dukes stage A, was found. A greater extent of dysplasia was found in rectosigmoidal adenomas in women, whereas more polyps were found in both distal and proximal parts of the colon among men. The size of adenomas and degree of dysplasia were unrelated to color of the lesions.

Fecal bile acid profiles of Japanese patients with adenomatous polyps of the large bowel: special reference to distribution, multiplicity, size and degree of dysplasia of the polyps

Bile acids have been implicated in carcinogenesis of the large bowel, and since epidemiological, clinical and histopathological studies suggest a link between adenomatous polyps and cancer of the large bowel, fecal bile acid profiles were studied in 33 patients with adenomatous polyps of the large bowel and these data were analyzed with particular reference to the distribution, multiplicity, size and degree of dysplasia of the polyps. The more polyps and the greater the severity of dysplasia, the higher was the excretion of total bile acids (mean mumol/day: single vs multiple polyps, 344.8 vs 369.1; mild vs moderate vs severe dysplasia, 347.5 vs 370.0 vs 399.3). However, in patients with larger polyps, total fecal bile acid excretion tended to be lower (mean mumol/day: large vs small polyps, 267.7 vs 389.5). These differences were not statistically significant. When fecal bile acid profiles were analyzed with respect to the extent of bacterial metabolism determined from the degree of dehydroxylation and oxidoreduction, there was a large variation with no consistency in relation to the factors studied among the polyp patients. Deconjugation of bile acids in feces was almost complete without difference among the patients. These results seem to indicate that the significance of bile acid in the development of adenomatous polyps in Japanese subjects is likely to be small.

Incidence of synchronous and metachronous colorectal carcinoma

Two hundred and twenty-three patients with colorectal carcinoma were treated consecutively at the University Hospital of South Manchester from May 1976 to January 1981. Twenty-four patients (10.7 per cent) were found to have more than one colorectal carcinoma. In 18 patients this was recognized either immediately or within 6 months of the initial diagnosis--synchronous carcinoma. In the other six cases a second carcinoma was found at a later time--metachronous carcinoma. The incidence of synchronous, and consequently the combined incidence of synchronous and metachronous carcinoma, was higher than previously documented. The anatomical distribution of the multiple carcinomas and the sex incidence in these patients was similar to that seen in patients with a single carcinoma of the large bowel. A high association of adenomatous polypi with multiple large bowel carcinomas was observed. The possibility of more extensive colonic resection in the younger patient with a favourable carcinoma is discussed.

[Gastric mucosal polyps--an irrelevant finding? Studies on the incidence and clinical significance]

Among about 20.000 patients who had a gastroscopy in a period of 6 years, 92 had gastric mucosal polyposis, diagnosed by endoscopy and histology, an incidence of 0.46%. Eight patients with an age average of 38 years had familial gastrointestinal adenomatosis, in six of them the criteria of Gardner's disease were fulfilled. The remaining 84 patients had an average age of 62 years. In patients with more than ten polyps the sex ratio (female to male) was 3.9:1. In 56 patients without familial gastrointestinal adenomatosis, coloscopy and(or) proctosigmoidoscopy was performed. In 18 there were polyps in the colon, in three an invasive carcinoma in an adenoma. In three further patients extensive carcinoma of the colon (in two with stenosis) was found. These observations suggest that patients with gastric mucosal polyposis have a higher incidence of colon polyps and carcinoma.

Colonoscopy in asymptomatic individuals with a family history of colorectal cancer

A prevalence screening program with colonoscopy was undertaken in four kindreds manifesting the cancer family syndrome. Forty-five percent of counseled patients underwent colonoscopy, providing 42 asymptomatic individuals. Seven patients (17%) were found to have adenomatous or villous polyps; two of these were malignant and one showed epithelial atypia. Three of the seven patients with polyps had multiple lesions. Only two patients had rectosigmoid polyps. From these limited data, colonoscopy is recommended as a useful screening procedure in individuals at high risk for colorectal cancer.

Spontaneous polyposis in the small intestine of germ-free and conventionalized BALB/c mice

The spontaneous polyposis in the small intestine of germfree (Gf) and conventionalized (Cv) BALB/c mice was studied. Gf mice were bred in our laboratory and maintained Gf in vinyl isolators. The first generation offspring of the Cv mice derived from the Gf mice was used as Cv animals. When they were 12 months old, the animals were killed under CO2 inhalation and autopsied carefully for the number and size of polyps with the aid of a dissecting microscope. The incidence of polyposis was higher in the Gf mice (68% in female and 89% in male) than in the Cv mice (37% in female and 51% in male). The number of polyps/mouse was also higher in the Gf mice (2.3 in female and 5.7 in male) than in the Cv mice (0.8 in female and 1.3 in male). All of the polyps were histopathologically adenomatous and developed only in the upper part (mainly duodenum) of the small intestine. The present study demonstrated that development of polyposis in the small intestine of BALB/c mice was suppressed by the presence of intestinal microflora.

Colorectal juvenile polyps: an epidemiological and histopathological study of 144 cases in Jordanians

The minimal incidence rate of colorectal juvenile polyps in Jordanians was 1.4 per 100 000 in the general population and 2.8 per 100 000 in children under 10 years of age. Out of 144 cases, nine had two to seven polyps and one juvenile polyposis coli. There was male preponderance and a mean age of 8 years: 96.5% of the polyps were in the rectum. Characteristically, stromal oedema, inflammation, ulceration with granulation tissue cap formation and gland regeneration were present. Epithelial hyperplasia was not uncommon and focal dysplastic change was occasionally noted, being always accompanied by hyperplastic change. Focal severe dysplasia was seen in one solitary juvenile polyp. It is concluded that varying degrees of focal epithelial atypia can occasionally develop in solitary juvenile polyps, rarely reaching severe dysplastic change. Malignant transformation in the commonly seen form of juvenile polyp (solitary type) is probably a rare phenomenon, but its frequency needs further evaluation.

[Duodenal polyps. Incidence, histologic substrate and significance]

378 duodenal polyps were identified by endoscopic biopsy since 1973 in the course of more than 25,000 oesophago-gastro-duodenoscopies, corresponding to an incidence rate of 1.5%. Heterotopias of the gastric mucosa and so-called inflammatory polyps were most frequent (35.7% and 35.2%, respectively), followed by hyperplasia of Brunner's glands (6.9%), lipid islets (2.9%) and lymphatic hyperplasia (1.8%). Histologically there was no correlate to the endoscopic findings. Hence, non-neoplastic polyps account for about 90% of duodenal polyps; they are harmless and generally produce no (or only minor) signs or symptoms. Clinically relevant polyps besides the primary and secondary malignant processes are the adenomas of the colon type (6.9%) and Peutz-Jeghers polyps (1.3%). Since these two may occur in gastrointestinal polyposis, "top-and-tail endoscopy" must be performed. The rate of complications of 15% in endoscopic loopectomy in the duodenum is clearly higher than that in the stomach and colon.

Fundic gland polyposis in patients without familial adenomatosis coli: its incidence and clinical features

Thirty-five cases of fundic gland polyposis detected by roentgenographic examination, gastrofiberscopy, and endoscopic biopsy were divided into two groups. The first group consisted of 23 cases without familial adenomatosis coli and is termed the nonadenomatosis coli group; the second group contained 12 cases with familial adenomatosis coli and is termed the familial adenomatosis coli group. Incidence of fundic gland polyposis was only 0.085% (23 of 27,000 cases) in the non-adenomatosis coli group but 38.7% (12 of 31 cases) in the familial adenomatosis coli group. In both groups, fundic gland polyps were multiple, small (less than 8 mm in diameter), and located in the body and fundus of the stomach. A solitary or large polyp was occasionally observed in the non-adenomatosis coli group. Histologic examination revealed simple hyperplasia of the fundic glands and microcysts in both groups. The age range was 51.6 +/- 12.3 yr (mean +/- SD) in the non-adenomatosis coli group and 25.3 +/- 8.6 yr in the familial adenomatosis coli group. The ratio of males to females was 5:18 in the non-adenomatosis coli group, and 7:5 in the familial adenomatosis coli group. The number of fundic gland polyps was smaller in the non-adenomatosis coli group than in the familial adenomatosis coli group. Our observations suggest that this lesion frequently coexists with familial adenomatosis coli, but that it is not specific to this disease.

Flexible sigmoidoscopy: diagnostic yield in 1015 patients

The purposes of our study were to 1) identify the number of neoplastic lesions (adenomatous polyps and cancer) diagnosable by flexible sigmoidoscopy (FS) in patients with symptoms of colorectal disease and 2) determine the age distribution of patients in whom neoplastic lesions are detected by FS. A total of 1015 patients, ages 20-89 years, underwent FS because of the following indications: rectal bleeding, occult blood loss, anemia, change in bowel habit, weight loss, and abdominal pain. FS examined a mean distance of 49 +/- 2 cm (SEM) in an average time of 11.5 min. A bowel preparation of 2 Fleet enemas was adequate in 95% of patients and the examination was well tolerated by all age groups. There were no complications encountered. Eight-five neoplastic lesions were identified in 78 patients. Fifty-four percent of all adenomatous polyps and 61% of the cancers were detected beyond 20 cm. Neoplastic lesions were identified in all adult decades studied, ranging from 3.2% of patients aged 20-40 years, 8.0% for patients between 40 and 60, and 10.1% from 60 to 80; with a peak yield of 11.2% in the 7th decade. Cancer was diagnosed only in patients more than 40 years; 3.3% of patients over 60 had carcinoma compared to 0.8% in patients less than 60. These data provide evidence for the value of FS as a safe initial diagnostic procedure to detect neoplastic lesions in symptomatic patients of all adult age groups.