Colorectal neoplasms in relation to non-alcoholic fatty liver disease in Korean women: a retrospective cohort study

Background and Aim: Metabolic syndrome has been associated with an increased risk for colorectal cancer. Non‐alcoholic fatty liver disease (NAFLD) is regarded as a hepatic manifestation of metabolic syndrome. We investigated whether NAFLD is associated with colorectal neoplasms in Korean women. Methods: This retrospective cohort study included data from 5517 women, aged 35–80 years, who underwent life insurance company health examinations between July 2002 and June 2006. Fatty liver disease was assessed by abdominal ultrasound, with NAFLD defined as fatty liver disease in the absence of alcohol use of > 40 g/week or other secondary causes. The incidence of colorectal neoplasms through December 2008 was obtained through medical certificate codes for insurance claims. The association between NAFLD and the risk of colorectal neoplasms was estimated using standard Cox proportional hazards models. Results: Of the study population, 15.1% were diagnosed with NAFLD. During follow‐up, 65 women were verified as having adenomatous polyps and 15 as having colorectal cancer. Adjusted relative risks (95% confidence interval [CI]) for adenomatous polyps by age, low high‐density lipoprotein‐cholesterol, and NAFLD were 1.12 (95% CI 1.09–1.15), 2.56 (95% CI 1.53–4.28) and 1.94 (95% CI 1.11–3.40). Adjusted relative risks (95% CI) for colorectal cancer by age and NAFLD were 1.23 (95% CI 1.17–1.29) and 3.08 (95% CI 1.02–9.34). Conclusions: Our findings demonstrate a significant relationship between NAFLD and colorectal neoplasms. Among the various manifestations of metabolic syndrome, NAFLD may predict the development of colorectal neoplasms in Korean women.     

非酒精性脂肪性肝病及其肝纤维化程度与结直肠腺瘤性息肉的关系

目的:探讨非酒精性脂肪性肝病(NAFLD)及其肝纤维化严重程度与结直肠腺瘤性息肉之间的关系。方法:选择2018年4月—2021年4月在安徽医科大学第三附属医院消化内科住院的符合条件的结直肠腺瘤息肉患者538例为腺瘤性息肉组,其中165例为高危腺瘤。选择同期就诊的结肠镜检查正常的495例患者为对照组,比较腺瘤性息肉组及高危腺瘤性息肉组与对照组一般资料及NAFLD患者数目之间的差异。将NAFLD患者通过APRI、FIB-4、NFS三种无创肝纤维化评分系统进行分层,分为进展期纤维化组和非进展期纤维化组,探讨NAFLD患者肝纤维化严重程度与结肠腺瘤性息肉及高危腺瘤性息肉的关系。结果:NAFLD是结直肠腺瘤性息肉和高危腺瘤性息肉的独立危险因素(OR分别为1.632和1.714,95%CI1.145～2.324和1.054～2.785,P均<0.05)。在对肝纤维化严重程度进行进一步分层中,进展期肝纤维化是结直肠腺瘤及高危腺瘤的独立危险因素。而非进展期肝纤维化组与无脂肪肝组患结直肠腺瘤及高危腺瘤的风险差异无统计学意义(P<0.05)。结论:NAFLD肝纤维化程度与结直肠腺瘤性息肉及高危...     

Sex-influenced association of non-alcoholic fatty liver disease with colorectal adenomatous and hyperplastic polyps

AIM To investigate the relationship between non-alcoholic fatty liver disease(NAFLD) and colorectal adenomatous and hyperplastic polyps.METHODS A retrospective cross-sectional study was conducted on 3686 individuals undergoing health checkups(2430 males and 1256 females). All subjects underwent laboratory testing,abdominal ultrasonography,colonoscopy,and an interview to ascertain the baseline characteristics and general state of health. Multinomial logistic regression analysis was performed to examine the association between NAFLD and the prevalence of colorectal adenomatous and hyperplastic polyps.Furthermore,the relationship was analyzed in different sex groups. Subgroup analysis was performed based on number,size,and location of colorectal polyps.RESULTS The prevalence of colorectal polyps was 38.8% in males(16.2% for adenomatous polyps and 9.8% for hyperplastic polyps) and 19.3% in females(8.4% for adenomatous polyps and 3.9% for hyperplastic polyps). When adjusting for confounding variables,NAFLD was significantly associated with the prevalence of adenomatous polyps(OR = 1.28,95%CI: 1.05-1.51,P 0.05) and hyperplastic polyps(OR = 1.35,95%CI: 1.01-1.82,P 0.05). However,upon analyzing adenomatous and hyperplastic polyps in different sex groups,the significant association remained in males(OR = 1.53,95%CI: 1.18-2.00,P 0.05; OR = 1.42,95%CI: 1.04-1.95,P 0.05) but not in females(OR = 0.44,95%CI: 0.18-1.04,P 0.05; OR = 1.18,95%CI: 0.50-2.78,P 0.05). CONCLUSION NAFLD is specifically associated with an increased risk of colorectal adenomatous and hyperplastic polyps in men. However,NAFLD may not be a significant factor in the prevalence of colorectal polyps in women.     

Colorectal cancer risk in first-degree relatives of patients with colorectal adenomatous polyp

BACKGROUND/AIMS: To evaluate any risk of colorectal cancer in first-degree relatives of patients with colorectal adenomatous polyp. METHODOLOGY: In a screening program-based cross-sectional study, 44821 subjects received an immunochemical fecal occult blood test using a 2-consecutive-day method. They were divided into two groups, according to the results of a self-completed questionnaire on family history of colorectal adenomatous polyps, and the positivity rate of an immunochemical fecal occult blood test as well as the positive predictive value for colorectal cancer were determined in these two groups. RESULTS: The fecal occult blood test was positive in 8.5% of subjects with family history and in 4.8% of subjects without family history, and the positive predictive value for colorectal cancer was 6.8% and 2.4% in subjects with and without family history of colorectal adenomatous polyps, respectively, indicating a significant difference in the positivity rate of the fecal occult blood test (P < 0.01) as well as the positive predictive value for colorectal cancer (P < 0.05) between these two groups. CONCLUSIONS: These results show that first-degree relatives of patients with colorectal adenomatous polyp have an increased risk for colorectal cancer, and that the subjects with family history of colorectal adenomatous polyps as well as cancers should be considered as a priority group for prevention of colorectal cancer.     

Epidemiology of a fast emerging disease in the Asia-Pacific region: non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is rapidly increasing in the Asia-Pacific and affects up to 30 % of the general population. In younger children, prevalence has been reported to be between 2.1 and 4.5 %. The prevalence of NAFLD increases with increasing age. NAFLD is more prevalent in men than women, but this trend fades in older age group. NAFLD is one of the most common causes of raised serum ALT levels and the latter is closely related to the presence of features of metabolic syndrome. NAFLD may contribute to metabolic syndrome in a similar way as visceral adiposity and can be an early predictor of metabolic disorders. NAFLD increases the risk of developing diabetes mellitus and is closely related to degree of glucose intolerance. A significant proportion of patients with NAFLD have impaired glucose tolerance or diabetes mellitus but with normal fasting blood glucose, highlighting the importance of oral glucose tolerance test in NAFLD patients with normal fasting blood glucose. Besides liver-related complications, NAFLD has been associated with cardiovascular complications, hyperuricemia, gout, chronic kidney disease, gallstone disease, colorectal adenomatous polyp, and polycystic ovarian syndrome. NAFLD seems to be related to host metabolic factors rather than viral factors and does not seem to affect severity of the liver disease in patients with chronic hepatitis B. On the other hand, hepatic steatosis may be related to both host metabolic and viral factors in patients with chronic hepatitis C and seems to adversely impact on the severity of liver disease and possibly response to antiviral therapy.     

Genetic testing and phenotype in a large kindred with attenuated familial adenomatous polyposis

BACKGROUND & AIMS: An attenuated form of familial adenomatous polyposis has been described, but the phenotype remains poorly understood. METHODS: We performed genetic testing on 810 individuals from 2 attenuated familial adenomatous polyposis kindreds harboring an identical germline adenomatous polyposis coli gene mutation. Colonoscopy was performed on mutation-positive persons. RESULTS: The disease-causing mutation was present in 184 individuals. Adenomatous polyps were present in 111 of 120 gene carriers who had colonoscopy at an average age of 41 years. The median number of adenomas was 25 (range, 0-470), with striking variability of polyp numbers and a proximal colonic predominance of polyps. Colorectal cancer occurred in 27 mutation carriers (average age, 58 years; range, 29-81 years), with 75% in the proximal colon. The cumulative risk of colorectal cancer by age 80 was estimated to be 69%. An average of 3.4 recurrent polyps (range, 0-29) were found in the postcolectomy rectal remnant over a mean of 7.8 years (range, 1-34 years), with 1 rectal cancer. CONCLUSIONS: This investigation shows that attenuated familial adenomatous polyposis in the kindreds examined shows a much smaller median number of polyps than typical familial adenomatous polyposis, a wide variability in polyp number even at older ages, and a more proximal colonic location of polyps and cancer, yet it is associated with an extremely high risk of colon cancer. The phenotype of attenuated familial adenomatous polyposis mimics typical familial adenomatous polyposis in some cases but in others is difficult to distinguish from sporadic adenomas and colorectal cancer, thus making genetic testing particularly important.     

Endoscopic identification and quantification of aberrant crypt foci in the human colon

BACKGROUND: Aberrant crypt foci may be precancerous lesions in the human colon. The occurrence of aberrant crypt foci was compared in patients with an endoscopically normal colon, known adenomatous polyps, and known colorectal cancer. METHODS: In 90 patients (30 colonoscopically normal, 30 with adenomatous polyps, 30 with colorectal cancers) magnification chromoscopy was performed to identify aberrant crypt foci in the distal 10 cm of the rectum. Representative biopsy specimens were obtained for histopathologic assessment. RESULTS: Aberrant crypt foci were readily identified. Median and (mean) numbers of aberrant crypt foci were as follows: endoscopically normal colon, 3.5 (5.0); adenomatous polyp(s), 4.0 (6.9); and colorectal cancer, 7.5 (9.9). The number of aberrant crypt foci detected was significantly associated (p = 0.02) with an increased odds that a patient would be in the group with known colorectal cancer (odds ratio = 1.11; 95% CI [1.02, 1.21]), but not in any other group. CONCLUSIONS: Despite a stepwise increase in the number of aberrant crypt foci across the 3 groups, aberrant crypt foci was significantly associated only with comorbid colorectal cancer. Aberrant crypt foci was not associated with adenomatous polyp(s) or normal colon. Additional studies are needed to further elucidate the role of aberrant crypt foci in the development of colorectal neoplasia in humans.     

Relationship of visceral adipose tissue to recurrence of adenomatous polyps

OBJECTIVES:   Insulin is a growth factor for colorectal cancer. Visceral adipose tissue (VAT) is strongly associated with insulin levels, and insulin and visceral obesity have been associated in cohort studies with colorectal cancer. The aim of this investigation was to determine whether VAT is associated with recurrence of adenomatous polyps, the precursor to colorectal cancer.
METHODS:   As an ancillary study to the Polyp Prevention Trial, a randomized clinical trial that evaluated the effect of a low-fat, high-fiber, high vegetable and fruit diet on adenomatous polyp recurrence, subjects at one clinical center underwent measurement of VAT with a single-slice CT scan through the L4–L5 interspace. The scan was performed around the time of the subject's year 4 colonoscopy that determined adenoma recurrence.
RESULTS:   Of 119 subjects, 44 of 84 men (52%) and 16 of 35 women (46%) had a recurrent adenoma ( p = 0.51). Body mass index (BMI) and weight at baseline and at year 4 colonoscopy were unrelated to adenoma recurrence. In a multivariate model including visceral fat quartile, remote history of polyps, gender, age, and randomization group, only remote history of polyps was statistically significantly associated with recurrent adenoma with a relative risk of 4.6 (95% CI 1.7, 12.4, p = 0.001). There was no consistent monotonic trend of increased or decreased risk of recurrence as one ascended quartiles of adipose tissue for visceral, subcutaneous, or total abdominal fat.
CONCLUSION:   In this study, no association between visceral adipose tissue and adenomatous polyp recurrence was observed. Further study and exploration of the role of VAT in adenoma progression is required.     

Clinicopathologic study of colorectal polyps and obesity in Korean adult]

BACKGROUND/AIMS: Obesity is a rising problem in industrialized countries. Numerous epidemiologic studies have shown a positive association between obesity and colorectal polyps. There are few studies investigating the association between colorectal adenomatous polyps and body fat composition in Korea. We tried to examine the relationship between body fatness and colorectal adenomatous polyps in health check-up subjects in Korea. METHODS: Six thousand seven hundred and six routine health check-up subjects, who visited our hospital between March 2002 and April 2005 and underwent distal colon examimation with sigmoidoscopy, were enrolled in this study. Among them, colonoscopy was done in 860 patients to evaluate the entire colon. We tried to reveal the relationship between body mass index (BMI) and size, location, number and histopathological type of polyps. BMI was used as an indicator of obesity. RESULTS: The mean value of BMI in total polyp-free group (23.8+/-2.9) was not different from that of the polyp group (24.5+/-2.8, p=0.09). The frequency of rectosigmoid polyps in obese patients (20.4%) was higher than that in non-obese patients (16.0%, p<0.05). The frequency of adenomatous polyp was not different between obese and non-obese group. Number of polyps (> or=4) correlated well with obesity. Moreover, age and triglyceride level in patients with colonic adenoma were significantly higher than in patients without colonic adenom. CONCLUSIONS: This study shows that obesity is not associated with colonic adenomatous polyp in Korean population. However, we observed that obesity may be associated with rectosigmoid colon polyps. Furthermore, age and triglyceride level might be the risk factors of colonic adenomatous polyps in Korean population.     

An Anti-adenoma Antibody, Adnab-9, May Reflect the Risk for Neoplastic Progression in Familial Hamartomatous Polyposis Syndromes

Patients with the hamartomatous polyposis Peutz-Jeghers and familial juvenile polyposis syndromes are predisposed to colorectal cancer but lack early genetic alterations found in adenomatous premalignant lesions. We studied hamartomatous polyps for the expression of an early preneoplastic colorectal neoplasia risk marker also found in familial adenomatous polyposis patients. Retrospective, genetic, and hospital archival tissue immunohistochemistry using Adnab-9, a premalignant marker often found in Paneth-like cells (PCs), was performed on sections of polyps from eight patients with Peutz-Jeghers syndrome, eight patients with familial juvenile polyposis, and 36 hyperplastic polyp control sections. Anti-α-defensin 5 (AD5), a universal PC marker, was also used to label a subgroup of sections. Hamartomatous polyposis patients also underwent specific genetic analysis. Eighty-nine percent of Peutz-Jeghers syndrome polyps labeled with Adnab-9 compared with 63% for AD5; 88% of familial juvenile polyposis sections also labeled with Adnab-9. Of the 36 hyperplastic polyp sections, only four (11%) labeled with Adnab-9 and one (3%) with AD5. Adnab-9 labeling of PCs in the epithelial elements of hamartomatous colonic lesions of hereditary hamartomatous syndrome patients reflects the predisposition to colorectal cancer, further justifying early intervention strategies.     

Folate Status and Risk of Colorectal Polyps in African Americans

Dietary folate status appears to influence risk for colorectal cancer possibly by alterations in DNA methylation and nucleotide precursor pools. Polymorphisms (677C→T and 1298A→C) in methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, determines enzyme activity. The frequency of polymorphisms in the gene varies extensively in different populations. We sought to determine the association between folate status, folate metabolism, DNA methylation, tobacco, alcohol consumption, and the risk of colorectal adenomas in African Americans. Among 58 patients who underwent a clinically indicated colonoscopy, 23 patients with histology confirmed colorectal polyps and 35 patients without were recruited for a case-control study. Blood samples were collected from fasting patients for determination of serum and red blood cell (RBC) folate, homocysteine, vitamin B₁₂, and methylation status. Polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) technique was performed to identify the MTHFR 677 C→T polymorphism and specific PCR was used to analyze adenomatous polyposis coli (APC) gene-promoter sequence methylation. Among 23 cases, 49 polyps (adenomatous, n = 41 and hyperplastic, n= 8) were identified. Twenty-eight (57%) of the polyps were on the left side and 21 (42%) were on the right side of the colon. There was no association between the presence of colon polyps and levels of folate (serum, RBC), vitamin B₁₂, or homocysteine. Forty-eight individuals (84%) were homozygous for 677 CC. Of these individuals, 18 (37.5%) had ≥1 colorectal polyps, whereas 30 (62.5%) had no polyps. Nine individuals were heterozygous for 677 CT, and 4 (44%) of these individuals had colon polyps. Eighty-eight percent of the APC gene-promoter sequences tested using peripheral blood DNA from patients were unmethylated. Among the individuals who showed APC methylation, 66% had polyps; 33% were polyp free using their blood DNA. There was highly significant association between smoking and alcohol consumption with the presence of a colon polyp (P= .0006 and P= .05, respectively). In conclusion, the lack of the 677 TT may be a significant risk factor for colon neoplasm in the African-American population. Smoking and alcohol consumption were found to be risk factors for colon polyps. APC gene-promoter sequence methylation found in peripheral blood may be an indicator of risk for polyp formation and an important screening tool.     

Selenoprotein levels in patients with colorectal adenomas and cancer

OBJECTIVES: Selenium is a trace mineral that, as a constituent of certain selenoproteins, acts as an antioxidant. Results of studies addressing a cancer protective effect of selenium have been controversial. The present study measured selenoprotein-P, extracellular glutathione peroxidase, and plasma selenium in patients with colon cancer and adenomatous colon polyps to determine whether patients who develop colorectal adenomas or cancer are selenium deficient. METHODS: Patients who presented to an endoscopy center for colonoscopy or who were referred to our institution with a newly diagnosed colorectal cancer were offered enrollment in the trial. Each patient underwent phlebotomy, usually immediately after colonoscopy. In all, 103 patients were enrolled in the study. Of these, 33 patients were found to have colorectal cancer, 35 adenomatous colon polyps, and 17 normal examinations. A total of 18 patients had other diagnoses and were not included in the study group. RESULTS: The mean age for the colorectal cancer group was 69 yr, for the adenomatous colon polyp group 62 yr, and for the normal group was 56 yr. The adenomatous colon polyp and normal groups were predominantly female. Based on one way analysis of variance tests, there was no significant difference in selenoprotein-P or plasma selenium levels or extracellular glutathione peroxidase activity among the three groups (p = 0.28, 0.098, and 0.35 respectively). CONCLUSIONS: The present data suggest that patients with adenomatous colon polyps and those with colorectal cancer are not selenium deficient.     

Is gastric cancer a new indication for surveillance colonoscopy? Colon cancer is increased in gastric cancer patients]

BACKGROUND/AIMS: It has been reported that the risk of gastric polyp is increased in various colonic polyposis syndromes or in series of patients with sporadic colonic polyps. However, there are only a few large case controlled studies of colon cancer incidence in gastric cancer patients who underwent colonoscopy. The aims of this study were to determine the incidence of colorectal neoplasm and to evaluate the necessity of colonoscopic surveillance in patients with gastric cancer. METHODS: We performed colonoscopy in 105 patients with gastric cancer who agreed to undergo colonoscopy before or after 6 months from gastric resection between January 2002 and December 2004 in Kangbuk Samsung hospital. As a control group, 269 consecutive, age and sex matched patients without gastric neoplasm on gastroscopy who underwent colonoscopy within 6 months for the evaluation of various gastrointestinal symptoms during the year 2004 were included. Endoscopic reports and pathological results were reviewed retrospectively. RESULTS: In the patient group, adenomatous polyps were diagnosed in 24/105 patients (22.9%) and colorectal adenocarcinoma in 10/105 patients (9.5%). In the control group, adenomatous polyps were diagnosed in 78/269 patients (29.0%) and colorectal adenocarcinoma in 2/269 patients (0.7%). The incidence of colorectal adenocarcinoma between the patient group and control group showed significant differences (odds ratio 11.04, p=0.003). CONCLUSIONS: The risk of colorectal adenocarcinoma increases significantly in patients with gastric cancer. We suggest that the patients with gastric cancer might carry a high risk for colorectal cancer whom require surveillance colonoscopy.     

Polyposis-Syndrome und Dünndarmkarzinome

Polyposis syndromes require special attention because of benign and malignant complications. Polyposis syndromes account for fewer than 1% of newly diagnosed colorectal cancers. The risk for extracolonic cancers is increased in most polyposis syndromes. Classification relies on the histologic type of polyp (adenomas, hamartomas, hyperplastic polyps), patient age at diagnosis, distribution within the gastrointestinal tract, polyp count, and extraintestinal features. Multiple adenomas (>10) are suspicious for underlying familial adenomatous polyposis, attenuated adenomatous polyposis, or MYH-associated polyposis (MAP). Hamartomatous polyposis syndromes include Peutz-Jeghers syndrome and familial juvenile polyposis. All syndromes except MAP are inherited with an autosomal dominant trait. This implies that first-degree relatives (parents, siblings, offspring) have a 50% risk of carrying the underlying germline mutation as well. Contacting a familial colorectal cancer center is advised in any uncertain cases. Polyposis syndromes are an important risk factor for small bowel cancer. We therefore review this rare but important neoplasm.     

Risk of colorectal adenoma in liver transplant recipients compared to immunocompetent control population undergoing routine screening colonoscopy

BACKGROUND: Immunosuppression following solid organ transplantation has been associated with a higher prevalence of cancers including colon cancer. However, the risk of colorectal adenoma following liver transplantation is unknown. The objective of this pilot study is to determine whether the prevalence of colorectal adenoma is increased in liver transplant recipients. METHODS: In this retrospective study, 25 patients who had liver transplantation at our institution between 1994 to 1997 and who underwent routine posttransplantation colonoscopy were compared with 50 controls who were undergoing routine screening colonoscopy. Transplant recipients who were younger than 45 years, survived less than 3 years following liver transplant, with history of inflammatory bowel disease, or prior history of colonic adenoma or cancer were excluded from the study. In both groups, colonoscopic diagnosis of polyp was confirmed by pathologic diagnosis of adenoma on biopsy. RESULTS: 25 (12M/13F, mean age 53 +/- 7 years) liver transplant recipients were compared with 50 controls (19M/31F, mean age of 59 +/- 7 years). In transplant recipients, colonoscopy was performed 41 +/- 19 months after liver transplantation. Seven (28%) liver transplant recipients (5M, 2F) and 4 (8%) controls (3F, 1M) were found to have adenomatous polyp (OR 4.5, 95% CI 1-21.2, P = 0.049). Malignant polyps were not detected in both groups. CONCLUSION: Liver transplant recipients appear to have an increased risk for developing colorectal adenoma. Early screening colonoscopy is warranted for this group of patients.     

Effects of sulindac on sporadic colorectal adenomatous polyps.

BACKGROUND: Although sulindac is known to cause regression of colorectal adenomatous polyps in familial adenomatous polyposis, less is known about the effect of sulindac on sporadic adenomas. The precise mechanisms of these effects also remain to be determined. AIMS: Sulindac was given to patients with sporadic colorectal adenomatous polyps to evaluate its effects on them, and histological analysis was performed to elucidate the mechanism of the polyp regression, as well the kind of adenomatous polys that are susceptible to the agent. SUBJECTS: 20 adenomatous polyps in 15 patients were studied. METHODS: Sulindac (300 mg daily) was given for four months, followed by colonoscopy with removal of the residual polyps. Polyp size, degree of atypia, inflammatory cell infiltration in the polyps, and immunostaining for mutant p53 product were evaluated before and after treatment. RESULTS: 13 of the 20 polyps shrank or disappeared. Patient sex, polyp location, size, degree of atypia, or p53 mutation did not affect the response, but polyps in older patients were more sensitive to sulindac. The degree of atypia or inflammatory cell infiltration was not affected by the treatment. A polyp containing a focal cancer was unresponsive. CONCLUSIONS: Sulindac can cause regression of sporadic colorectal adenomatous polyps.     

Frequency of polyps in patients undergoing surgery for colorectal cancer

INTRODUCTION: Epidemiologic and molecular biologic studies have already demonstrated that adenomatous colonic polyps are precancerous diseases. The main indication of the colonoscopy in the surveillance of colorectal cancer treated patients is the diagnosis and resection of adenomatous polyps. AIM: To study the frequency of adenomatous polyps after surgically resection of colorectal cancer. MATERIAL AND METHODS: Sixty eight patients, mean age 59 years old, with total resection of colorectal cancer, submitted to various colonoscopies during the follow up were studied retrospectively. The histological type and the characteristics of the polyp were described. RESULTS: The frequency of polyps was 18%, being higher in the patients with more than 45 years (20%). The site of the polyps was in the left colon in 38% of the patients with cancer. The histological type of adenomas was tubular in 61%, villous in 22% and mixed in 17%. DISCUSSION: As described by other authors, the incidence of polyps were higher after 45 years old and more than a half of them were tubular. The frequency of polyps was higher in the first two years of follow up.     

Predictive value of morphologic characteristics in rectosigmoid adenomatous polyps for the probability of synchronous polyps or cancer in the proximal colon.

BACKGROUND/AIMS: Sigmoidoscopy is performed more frequently than colonoscopy, especially for screening purposes and searching for colorectal neoplasm. The necessity of colonoscopy in patients with an adenoma ofor=11 mm) polyps. These groups were compared regarding the presence of proximal adenoma and advanced proximal neoplasia (>10 mm adenoma and/or villous histology and/or high grade dysplasia or cancer). Polyps found in the rectum and sigmoid colon were considered as distal polyps and polyps other than these were considered as proximal polyps. RESULTS: In this study, of 1124 consecutive patients who underwent colonoscopy between April 1997 and January 2002, 184 (16%) had 258 adenomatous polyps in the rectosigmoid area. The polyps were diminutive (or=11 mm) in 33 patients. Forty-one of the patients (39%) with diminutive polyps, 20 of the patients (43%) with small polyps and 19 of the patients (57%) with large polyps had neoplasm in the proximal bowel. In these patients, advanced proximal neoplasm was found in 8 (8%), in 6 (13%) and in 11 (33%), respectively. There was no difference regarding the presence of neoplasm in the proximal colon between these groups. The rate of advanced proximal neoplasm was found to be significantly higher in the group with large polyps in the rectosigmoid area than in the groups with small and diminutive polyps (p<0.05). In 104 patients (57%) with polyp(s) in rectum and sigmoid colon, no associated polyp or cancer was encountered in the proximal colon. CONCLUSION: Colonoscopy is indicated when adenomatous polyp, regardless of size, is found on rectosigmoidoscopy performed because of symptoms.     

APC I1307K increases risk of transition from polyp to colorectal carcinoma in Ashkenazi Jews

BACKGROUND & AIMS: The I1307K allele of the APC gene has been shown to confer a modestly elevated risk of colorectal cancer in the Ashkenazi Jewish population (relative risk, 1.5-1.7). However, it is unclear whether the alteration predisposes to adenomas and whether the genetic information can be used in clinical practice. To further address the pathogenic significance of I1307K, we offered both a genetic test and a screening program to individuals considered to be at increased risk for colorectal cancer. We compared the prevalence of polyps and their characteristics between carriers and noncarriers. METHODS: Invitations to participate in a DNA and colonoscopy screening program were mailed, together with a family questionnaire, to 3540 households forming the Jewish Community in Ottawa. The I1307K variant was analyzed in 242 eligible respondents who were selected because they had a personal or family history of colon cancer. Nearly 80% of these respondents (n = 189; age range, 32-83 years) consented to undergo a single colonoscopic examination. RESULTS: The overall carrier frequency of I1307K in the study group was 10.3%. A higher proportion of heterozygous gene carriers was found in the subgroup of colon cancer survivors (27%) than among asymptomatic individuals (8%, P < 0.02). A total of 59 polyps were identified in 44 subjects. Histologically confirmed adenomatous polyps were diagnosed in 11.8% of carriers and 12.8% of noncarriers (P > 0.5). No significant differences in polyp size, multiplicity, location, degree of villosity, or age-dependent prevalence were found between the 2 groups of participants. CONCLUSIONS: The high frequency of I1307K colorectal cancer patients found in the Ashkenazi Jewish community of Ottawa and the equivalent proportion of carriers and noncarriers who developed adenomatous polyps suggest that in this community, I1307K is associated with a significant predisposition to carcinoma but not adenoma.     

Colonic polyps in children and adolescents.

Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of colorectal cancer in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome, FAP, AFAP and MYH-associated polyposis, are discussed in the present review.