Surveillance after positive colonoscopy based on adenoma characteristics

BackgroundPatients with adenomatous polyps are at increased risk for developing colorectal cancer based on the characteristics and number of polyps, but less is known about the individual and combined contribution of these factors. This study aimed to better characterize the risk of advanced adenoma and cancer in patients with positive baseline colonoscopy.MethodsPatients who had polyps at baseline colonoscopy were included in this retrospective cohort study (N = 1165) and were categorized into 6 groups: (1) 1–2 non-advanced adenomas (NAA’s), (2) ≥3 NAA’s, (3) advanced tubular adenoma, (4) small tubulovillous adenoma (TVA), (5) large TVA and (6) multiple advanced adenomas (MAA’s). Findings at surveillance colonoscopy were documented in each group.ResultsThe combined incidence of advanced adenoma, ≥3 NAA’s, and colorectal cancer at surveillance colonoscopy was significantly higher in the baseline large TVA (29.2%) than small TVA groups (13.5%, P < 0.001), as well as in the MAA’s group (44.1%) compared with large TVA group (P = 0.02). The incidence of colorectal cancer, however, was not significantly different between the groups.ConclusionsThe size of the polyp and the number of advanced lesions are more important than its histology for predicting the risk of high-risk metachronous lesions at follow-up.     

The effect of metformin on the recurrence of colorectal adenoma in diabetic patients with previous colorectal adenoma

Purpose

Existing studies suggest that metformin lowers the risk and mortality of colorectal cancer. However, the effect of metformin on the suppression and prevention of colorectal adenomas is not clear. The aim of this study was to evaluate the effect of metformin on the recurrence of colorectal adenoma in diabetic patients with previous colorectal adenoma.

Methods

Among 423 diabetic patients who underwent surveillance colonoscopy after resection of colorectal adenoma between 2005 and 2011, 257 patients were retrospectively reviewed. The patients were divided into two groups: one group comprising 106 patients who took metformin and another group comprising 151 patients who did not take metformin. The clinical characteristics, colorectal adenoma recurrence, and valuable factors for adenoma recurrence were analyzed.

Results

At surveillance colonoscopy after colonoscopic polypectomy for adenoma, 38 patients (35.8%) exhibited colorectal adenoma among 106 patients who took metformin, compared with 85 patients (56.3%) with colorectal adenoma among 151 patients who did not take metformin (odds ratio 0.434, 95% confidence interval 0.260–0.723, P = 0.001). Multivariate Cox analysis showed that metformin was associated with decreased recurrence of colorectal adenoma (hazard ratio 0.572, 95% confidence interval 0.385–0.852, P = 0.006) in diabetic patients with previous colorectal adenoma. The cumulative probability of colorectal adenoma recurrence was significantly lower in the metformin group than in the non-metformin group (P = 0.001).

Conclusion

Metformin use in diabetic patients with previous colorectal adenoma is associated with a lower risk of colorectal adenoma recurrence.

     

410例患者结直肠腺瘤与幽门螺杆菌感染特征及相关性分析

目的　探讨结直肠腺瘤与幽门螺杆菌感染的关系。 方法　连续性收集在上海交通大学医学院附属仁济医院内镜中心同时行胃镜及结加肠镜的患者共410例患者的病例资料（其中结直肠腺瘤者74人,正常对照组336人）。比较结直肠腺瘤组和健康对照组幽门螺杆菌感染情况的差异。并将结直肠腺瘤组分别按腺瘤的数目、最大径、病理分型分亚组,比较各亚组与幽门螺杆菌感染情况。统计学分析采用t检验与卡方检验,P < 0.05 被认为具有统计学差异。 结果　结直肠腺瘤组和健康对照组幽门螺杆菌感染阳性率分别为29.73%和19.34%,前者高于后者,差异均有统计学意义（P＜0.05）。按腺瘤数目、最大径、病理分型分亚组,各亚组组内幽门螺杆菌感染阳性率差异均无统计学意义（P均＞0.05）,但按递进分层与对照组相比均有统计学差异（P均小于0.05）。 结论　结直肠腺瘤可能与幽门螺杆菌感染有直接相关,同时幽门螺杆菌对腺瘤的发展可能有促进作用。     

High frequency of colorectal neoplasia in patients with sporadic adenomas or adenocarcinomas of the papilla of Vater: The same adenoma-carcinoma sequence?

BackgroundData on the frequency of colorectal neoplasia in sporadic ampullary tumors remains scarce.MethodsWe retrospectively reviewed 135 patients undergoing endoscopic ampullectomy from January 2018 to July 2021, and identified 95 patients with sporadic ampullary adenoma who underwent total colonoscopy. Colonoscopy findings were compared with 380 asymptomatic controls using the chi-squared test. Whole-exome sequencing (WES) was performed on one patient with synchronous adenomas of the ampulla of Vater and ascending colon.ResultsColorectal polyps were present in 60% of Cases vs. 34.7% of Controls (P = 0.001), advanced adenoma in 20% vs. 5.5%, and adenocarcinoma in 4.2% vs. 0.8%. Cases tended to have larger polyps than Controls (P<0.001), while there was no difference in polyp location and histology between the two groups. The odds ratio of all the colorectal lesions, advanced colorectal adenoma and adenocarcinoma in Cases was 1.7, 4.2, and 4, respectively. WES in one patient revealed that both of ampullary adenoma and colonic adenoma shared somatic ABCB1 mutation.ConclusionsThe frequency of colorectal polyps or neoplasia was significantly higher in Cases than Controls. We proposed that ampullary neoplasia is analogous to colon lesions and warrants total colonoscopy screening in patients diagnosed with ampullary tumors.     

Chronic hepatitis C as a risk factor for colorectal adenoma

Introduction

Over the last decade, epidemiologic studies have determined a relationship between chronic hepatitis C (CHC) and malignancies other than hepatocellular carcinoma (HCC), particularly in gastrointestinal malignancies. This study aims to evaluate the incidence of colorectal adenomas and advanced neoplasia in CHC patients compared to the general population and to evaluate whether CHC infection is an independent risk factor for colorectal adenomas and advanced neoplasia.

Methods

This is a retrospective, case–control study. CHC patients who underwent screening colonoscopy between September 2006 and September 2010 were compared to randomly selected non-hepatitis C controls undergoing screening colonoscopy during the same period. Multivariate analysis was performed taking into account the known risk factors for colorectal adenoma.

Results

Two hundred thirty-three CHC patients and 466 controls that underwent screening colonoscopy were included in the study. CHC patients were younger and more likely to be male, smoker and have HIV infection compared to the control group (p?<?0.05). CHC group had a significantly higher number of patients with adenomas (adenoma detection rate of 37.8 vs. 30.3 %; p?=?0.04) and hyperplastic polyps (p?=?0.01) detected on screening colonoscopy. The total number of adenomas detected was also higher in the CHC group; however, this was not statistically significant (0.69 vs. 0.58 per patient; p?>?0.05). CHC patients were twice more likely to have advanced neoplasia detected compared to non-hepatitis C patients (odds ratio 2.04, 95 % confidence interval?=?1.20–3.49; p?=?0.03). CHC group was also more likely to have adenomas of ≥6 mm (p?=?0.005) and macroadenomas of ≥1 cm (p?=?0.02).

Limitations

Limitations include the single-center, retrospective design of the study.

Conclusions

Our study is the first to demonstrate a significantly higher rate of adenomas, advanced neoplasia, and hyperplastic polyps in CHC patients compared to the general population. On multivariate analysis, CHC infection was found to be an independent risk factor for colorectal adenoma, particularly advanced neoplasia. Larger prospective studies are needed to strengthen our findings which may have implications for colorectal cancer screening.     

The effect of small or diminutive adenomas at baseline colonoscopy on the risk of developing metachronous advanced colorectal neoplasia: KASID multicenter study

BackgroundThe clinical significance of diminutive or small adenomas remains ill defined.AimsWe evaluated the clinical impact of diminutive or small adenomas at baseline on the risk of developing metachronous advanced colorectal neoplasia (CRN).MethodsThis multicenter, retrospective cohort study included 2252 patients with 1 or more colorectal adenomas at baseline and subsequent follow-up colonoscopy. Baseline colonoscopy findings were classified into 5 groups: 1 or 2 tubular adenomas (TAs) (<10 mm); 3–10 diminutive TAs (≤5 mm); 3–10 TAs, including 1 or 2 small adenomas (6–10 mm); 3–10 TAs, including 3 or more small adenomas; and advanced adenoma.ResultsIn multivariate analysis, after adjusting for possible confounding variables (age at baseline, sex, body mass index, smoking habits, family history of colorectal cancer, regular use of aspirin or NSAIDs, and adenoma location), 3–10 TAs including 3 or more small adenomas (hazard ratio [HR] = 2.36, p = 0.034) and advanced adenoma (HR = 2.14, p < 0.001) were independent predictors for the risk of developing metachronous advanced CRN. However, 3–10 diminutive TAs or 3–10 TAs, including 1 or 2 small adenomas, were not associated with this outcome.ConclusionsMultiplicity of diminutive TAs, without advanced lesions, showed no clinical significance for risk of developing metachronous advanced CRN.     

Clinical impact of colonoscopy for patients with early gastric cancer treated by endoscopic submucosal dissection: A matched case–control study

BackgroundGastric cancer frequently occurs synchronously with colorectal cancer (CRC).AimsThe aim of the present study was to assess the value of colonoscopy in patients with primariy early gastric cancer (EGC) indicated for endoscopic submucosal dissection (ESD) and to identify predictors for the risk of high-risk adenomas.MethodsA total of 130 patients with EGC, who underwent both colonoscopy and gastric ESD, and 260 controls matched for age and sex, who underwent a colonoscopy as part of our institutional health check-up program.The prevalence of high-risk adenomas in EGC patients vs. controls was evaluated.ResultsHigh-risk adenomas were found in 43 (33%) EGC patients and 37 (14%) controls (P < 0.01). Multivariate analysis showed the presence of EGC was significantly associated with high-risk adenoma [odds ratio (OR) 2.8, 95% confidence interval (CI): 1.7–4.9]. Among EGC patients, high serum CEA level (OR 2.4, 95% CI: 1.2–5.0) was an independent predictor for high-risk adenoma.ConclusionsPatients with EGC had a significant risk for colorectal cancer. When endoscopists detected an early gastric cancer indicated for ESD, colonoscopy should be considered for EGC patients with high serum CEA levels.     

The association between location,age and advanced colorectal adenoma characteristics: a propensity-matched analysis

Purpose: Evidence supports an association between certain colorectal adenoma characteristics and predisposition to cancer. The association between anatomical location of colorectal adenoma, age and advanced adenomas needs attention. The objective of this study was to evaluate the possible association between occurrence of sporadic advanced adenomas with location and age.

Materials and methods: A cross-sectional study using baseline data from index colonoscopy from a randomized controlled trial evaluating chemopreventive treatment against recurrence of colorectal adenomas was performed. Inclusion criteria for patients were one adenoma of >1?cm in diameter or multiple adenomas of any size, or an adenoma of any size and familial disposition for colorectal cancer. Multivariate regression and propensity score-matched analyses were used to correlate location of adenomas and age with advanced adenoma features.

Results: In this study, 2149 adenomas were removed in 1215 patients. Advanced colorectal adenomas primarily occurred in the anal part of the colon. Older age was associated with more adenomas and more oral occurrence of adenomas, as well as a higher risk of advanced adenomas. Surprisingly, specifically for the oral adenomas the risk of advanced adenoma seems to be lower for older patients compared with younger.

Conclusions: This study presents new results with regard to association between age, location of adenomas and risk of advanced adenomas. The results indicate that sigmoidoscopy for screening purposes may be obsolete, and add to the existing literature on which future guidelines for screening may be based.     

Immunohistochemical Expression of Matrix Metalloproteinase-7 in Human Colorectal Adenomas Using Specified Automated Cellular Image Analysis System: A Clinicopathological Study

Background/Aim:

To evaluate the immunohistochemical expression of matrix metalloproteinase-7 (MMP-7) in colorectal adenomas, and to correlate this expression with different clinicopathological parameters.

Patients and Methods:

The study was retrospectively designed. Thirty three paraffin blocks from patients with colorectal adenoma and 20 samples of non-tumerous colonic tissue taken as control group were included in the study. MMP-7 expression was assessed by immunohistochemistry method. The scoring of immunohistochemical staining was conducted utilizing a specified automated cellular image analysis system (Digimizer).

Results:

The frequency of positive immunohistochemical expression of MMP-7 was significantly higher in adenoma than control group (45.45% versus 10%) (P value < 0.001). Strong MMP-7 staining was mainly seen in adenoma cases (30.30%) in comparison with control (0%) the difference is significant (P < 0.001). The three digital parameters of MMP-7 immunohistochemical expression (Area (A), Number of objects (N), and intensity (I)) were significantly higher in adenoma than control. Mean (A and I) of MMP-7 showed a significant correlation with large sized adenoma (≥ 1cm) (P < 0.05), also a significant positive correlation of the three digital parameters (A, N, and I) of MMP-7 expression with villous configuration and severe dysplasia in colorectal adenoma had been identified (P < 0.05).

Conclusion:

MMP-7 plays an important role in the growth and malignant conversion of colorectal adenomas as it is more likely to be expressed in advanced colorectal adenomatous polyps with large size, severe dysplasia and villous histology. The use of automated cellular image analysis system (Digmizer) to quantify immunohistochemical staining yields more consistent assay results, converts semi-quantitative assay to a truly quantitative assay, and improves assay objectivity and reproducibility.     

Cyclooxygenase-2 Expression in Colorectal Adenomas

PURPOSE: Cyclooxygenase-2 is an important target for nonsteroidal anti-inflammatory drugs in suppressing colorectal tumorigenesis. To evaluate the role of cyclooxygenase-2 in sporadic colorectal adenoma, we correlated cyclooxygenase-2 expression in adenomas with other adenoma characteristics. METHODS: Cyclooxygenase-2 expression was evaluated immunohistochemically in 95 endoscopically resected colorectal adenomas. RESULTS: Cyclooxygenase-2 was expressed mainly in the cytoplasm of adenoma cells, where it was seen in 74 percent (70/95) of adenomas. Expression was related significantly to grade of dysplasia (P < 0.001) and tumor size (P = 0.028). Multivariate logistic regression analysis showed cyclooxygenase-2 expression in adenoma cells to be independently associated with grade of dysplasia (P = 0.001). CONCLUSION: Observed associations suggest that cyclooxygenase-2 plays an important role in progression of the adenoma-to-carcinoma sequence.     

Number of aberrant crypt foci in the rectum is a useful surrogate marker of colorectal adenoma recurrence

Aim: Endoscopic screening and removal of colorectal adenomas can reduce the incidence of colorectal cancer. However, given the possibility of adenoma recurrence, surveillance colonoscopy is currently recommended after the initial screening and removal of colorectal adenomas. Aberrant crypt foci (ACF) have been shown to serve as a reliable surrogate marker of colorectal carcinogenesis. In this study, the relationship between the number of ACF at the initial endoscopic polypectomy and the likelihood of colorectal adenoma recurrence after polypectomy were investigated. Methods: High‐magnification chromoscopic colonoscopy was performed in 82 subjects who underwent endoscopic polypectomy to identify ACF in the lower rectum. Surveillance colonoscopy was then performed 3 years after the baseline polypectomy at Yokohama City University Hospital. Results: The number of ACF was greater in patients who showed adenoma recurrence (7.88 ± 6.35) than in those who did not (2.19 ± 2.95) (P < 0.001). Receiver–operating curve analysis showed that the number of ACF was a highly specific predictor of the risk of adenoma recurrence. Conclusions: This is the first study conducted to investigate the relationship between the number of ACF after endoscopic polypectomy and the likelihood of recurrence of colorectal adenomas. These results suggest that the number of ACF is a useful predictor of the likelihood of colorectal adenoma recurrence.     

Patient age and duration of colonoscopy are predictors for adenoma detection in both proximal and distal colon

AIM: To investigate the relation of patient characteristics and procedural parameters to the endoscopic detection rate of colonic adenomas. Further to study,which factors may be capable to predict the localization of adenomatous lesions.METHODS: We used the data base of a prospective randomized colonoscopy study(The Colo Cap trial) to identify patients being diagnosed with colon adenoma. Logistic regression analysis was conducted to reveal predictors for adenoma detection in the entire colon and also with respect to the proximal and distal part. Covariates including age, gender, duration of colonoscopy and comorbidities were defined to determine association between predictors and adenoma detection.RESULTS: Equal numbers of adenomas were detected in the proximal and distal side of the splenic flexure [126(57%) vs 94(43%), P = 0.104]. Simultaneous occurrence of adenomas in both sides of the colon was rare. The appearance of both proximal and distal adenoma was associated with increasing age(P = 0.008 and P = 0.024) and increasing duration of colonoscopy(P < 0.001 and P = 0.001). Male gender was a predictor for adenoma detection in the proximal colon(P = 0.008) but statistical significance was slightly missed with respect to the distal colon(P = 0.089). Alcohol abuse was found to be a predictor for the detection of distal adenoma(P = 0.041). CONCLUSION: Increasing age and longer duration of colonoscopy are factors with a strong impact on adenoma detection both in the proximal and distal colon. Since proximal adenomas occurred in absence of distal adenomas, complete colonoscopy should be performed for screening.     

结直肠癌合并高风险性腺瘤内镜治疗时机的临床研究

目的 针对结直肠癌合并高风险性腺瘤可择期外科手术的患者,探讨内镜下治疗的合适时机.方法 收集2013年1月至2018年6月经山东省威海市立医院诊治结直肠癌合并高风险性腺瘤的患者88例,将患者分为二组.A组52例患者,伴发高风险性腺瘤共96枚,该组患者先行结直肠癌外科手术,术后半年内行内镜下高风险性腺瘤治疗;B组36例患...     

p53 expresado en la mucosa gástrica de pacientes infectados por Helicobacter pylori

BackgroundHelicobacter pylori (Hp) is recognized as a type 1 carcinogen for gastric cancer associated with pre-neoplastic lesions (atrophy and intestinal metaplasia [IM]). Its relation with p53, which intervenes in the cell cycle, has had contradictory results.AimsTo analyze p53 expression in gastric mucosa and its relation with Hp infection.MethodsA 3-month prospective, observational, cross-sectional study was conducted. Patients that had no evidence of acute or clinically significant gastric pathology had biopsies taken according to the Sydney system at the Hospital Juárez de México and the histopathologic studies were done at the Hospital Español de México.ResultsHp prevalence was 32.7% in 104 patients. There were no cases of atrophy or dysplasia. A total of 91% of the infected patients were positive for p53. Of the non-infected patients, 14% were positive for p53 and 60% of them had IM. Of the IM patients, 75% presented with positive p53. Of the patients without IM, 31 presented with positive p53, and Hp was positive in 85% of them. There was association between Hp and p53 and between p53 and IM (P<.0001 and P<.0006, respectively).ConclusionsSignificant association was shown between Hp and p53 expression, even in patients with pre-neoplastic lesions that no longer presented with Hp. Given that the identification of pre-neoplastic lesions is important for the prevention of cancer, immunohistochemistry could benefit routine biopsy carried out during endoscopy for the detection of Hp, by identifying patients with expression of the important oncogene regulator, p53.     

Infección por Helicobacter pylori y su asociación con el consumo de alcohol. Estudio de casos y controles

IntroductionThere is a high prevalence worldwide of Helicobacter pylori (Hp) infection associated with gastritis and extending to gastric cancer. Reports have suggested that alcohol has antibacterial action and that its concentration and the amount consumed reduce the risk for Hp infection. In contrast, different studies suggest that tobacco and coffee consumption are risk factors for Hp infection, but their results are controversial.AimsTo compare the frequency of alcohol consumption in patients infected by Hp with that of non-infected subjects and, as a secondary aim, to compare the association of smoking and coffee consumption with Hp infection.Material and methodsA case-control study was conducted on Sinaloa State workers that underwent endoscopy and the Hp serology test. Cases were defined as patients with a positive Hp serology test or a positive biopsy with the rapid urease test. Alcohol consumption was categorized as: no consumption, low-risk, and at-risk. The sample included 269 subjects per group. Odds ratio (OR) and 95% confidence interval (CI) were calculated.ResultsIn both groups, the mean age of the subjects was 45.7 (SD: 9) years (P=.99), 139 of the subjects were women (51.7%) and 130 were men (48.3%); alcohol consumption was present in 108 (40.1%) and 85 (31.6%) of the cases and controls, respectively (P=.039), OR 1.45 (95%CI 1.019-2.069). The quantity of grams of alcohol in subjects with at-risk consumption was significant; However, there were no significant differences in relation to smoking and coffee consumption between the groups.ConclusionsAn association between alcohol consumption and HP infection was observed and no relation with HP infection was found with respect to smoking and coffee consumption.     

Clinical significance of small colorectal adenoma less than 10 mm: the KASID study

BACKGROUND/AIMS: Polypectomy is the current modality of choice to prevent benign colorectal adenoma from progressing to an invasive cancer. However, in cases of small colorectal adenoma, it remains unclear as to whether polypectomy is actually an effective treatment modality. We evaluated the clinical significance of polypectomy in cases of small colorectal adenomas, measuring less than 10 mm. METHODOLOGY: All colonoscopies were performed at 11 Korean tertiary medical centers, between July 2003 and March 2004. A total of 5996 colorectal adenomas were detected and divided into 5 groups according to their size (Group 1; 1-5 mm, Group 2; 6-7 mm, Group 3; 8-9 mm, Group 4; 10-19 mm, Group 5; more than 20 mm). The term 'advanced adenoma' refers here to tubular adenomas with diameters of at least 10 mm, or to tubulovillous, villous, or high-grade dysplasia, irrespective of size. 'Cancer' here is defined as the invasion of malignant cells beyond the muscularis mucosa. RESULTS: As the sizes of the adenomas increased, the prevalence of advanced adenoma was also observed to increase. In Groups 2 and 3, the prevalence of tubulovillous or villous adenoma were higher than was expected (5.2% and 6.6%, p < 0.001). Interestingly enough, in Group 2, the prevalence of cancer was at least as high as in Group 4 (0.7% vs. 0.5%, p < 0.001). CONCLUSIONS: In cases of small colorectal adenomas, measuring between 6 and 9 mm, the prevalence of cancer was at least as high as that seen in the cases of colorectal adenomas measuring between 10 and 19 mm. Therefore, small colorectal adenomas measuring between 6 and 9 mm should not be ignored, in order to decrease the prevalence of colorectal cancer.     

Increased expression of matrix metalloproteinase-7 in invasive early gastric cancer

Background Matrix metalloproteinase-7 (MMP-7), a proteolytic enzyme, is suspected to play an important role in the progression of various cancers. To clarify the clinical importance of MMP-7, we retrospectively analyzed MMP-7 expression in gastric epithelial tumors.Methods We tested 201 lesions (from 172 patients) of surgically or endoscopically resected gastric epithelial tumors (gastric cancer, 158 lesions; gastric adenoma, 32 lesions; hyperplastic polyp, 11 lesions). MMP-7 expression was immunohistochemically examined. Sections with immunostaining signals in more than 30% of tumor cells were judged to show positive expression.Results MMP-7 was expressed in 33.3% (67/201) of all lesions. MMP-7-positive tumors were significantly more frequent in diffuse-type adenocarcinomas (62.2%; 28/45) compared with intestinal-type lesions (31.9%; 36/113; P < 0.001). Cancers invading the submucosa or deeper (60.5%; 46/76) were showed positivity significantly more frequently than mucosal cancers (22.0%; 18/82; P < 0.001). MMP-7-positive lesions increased with the progression of gastric epithelial tumors, including adenomas, mucosal cancers, and cancers invading the submucosal layer or deeper (P < 0.001). MMP-7 expression occurred significantly more often in lymphatic invasion-positive cancers (65.1%; 41/63) than in lymphatic invasion-negative cancers (24.2%; 23/95; P < 0.001).Conclusions The MMP-7-positive rate increased with the progression of gastric epithelial tumors, such as adenoma, mucosal cancer, and cancer invading the submucosal layer or deeper. MMP-7 was significantly associated with aggressive pathological phenotypes of cancer. The detection of the MMP-7 protein may be useful in pretherapeutic diagnosis.     

Type 2 diabetes mellitus: the impact on colorectal adenoma risk in women

OBJECTIVES: Increased risk for colorectal cancer (CRC) has been associated with type 2 diabetes. Despite several studies linking insulin resistance to increased CRC risk, there are limited data on colorectal adenoma risk in diabetic women. We hypothesized that diabetic women would have increased rates of colorectal adenomas relative to a group of nondiabetic women. METHODS: Colorectal adenoma rates were determined in 100 estrogen-negative women with type 2 diabetes mellitus and compared with 500 nondiabetic, estrogen-negative controls. Adenomas were defined as any adenoma or advanced adenoma (villous or tubulovillous features, size >1 cm or high-grade dysplasia). A multivariate model including age, race, diabetes, hypertension, hypercholesterolemia, body mass index, and nonsteroidal anti-inflammatory drug status was used to determine the independent effects of diabetes on colorectal adenoma incidence. RESULTS: Diabetics as compared with nondiabetics had greater rates of any adenoma (37%vs 24%, p= 0.009) and advanced adenomas (14%vs 6%, p= 0.009). Two hundred forty-five obese subjects compared with 355 nonobese subjects had a higher rate of any adenoma (32%vs 22%, p= 0.001). Obese diabetics compared with nonobese, nondiabetics had greater rates of any adenoma (42%vs 23%, p< or = 0.001) and advanced adenomas (19%vs 7%, p< or = 0.001). Multivariate analysis showed that adenomas and advanced adenomas were independently predicted by diabetes (p < 0.05) and adenomas by age. DISCUSSION: Women with type 2 diabetes mellitus had higher rates of colorectal adenomas as compared with lean and nondiabetic women. This finding adds to the evidence that type 2 diabetes is an important factor in the progression of the adenoma-carcinoma sequence.     

Differing proliferative responses in proximal and distal colons of growing rats fed food eaten by adenoma patients

Animal dietary studies related to human colorectal carcinogenesis are usually based on AIN-76A diet, which is dissimilar to human food in source, preparation, and content. Our aim was to examine colonic epithelial proliferation in rats fed a diet based on the mean daily food intake of adenoma patients. Foods were prepared as reported by the adenoma patients and dehydrated; 64 Sprague-Dawley rats were fed either “human adenoma” or AIN-76A diet and every eight weeks, eight from each group were sacrificed. Both groups gained weight equally, had no colonic histological changes, but during the study showed progressive lengthening of colonic crypts (P<0.01) and decreased proliferation (P<0.05) in distal colons. Compared to controls, rats fed human adenoma diet had significantly longer crypts (P<0.01) and more labeled cells (P<0.05) at 32 weeks; overall they had increased proliferation (P<0.01), most significantly in the distal colon. Thus, food eaten by adenoma patients induced hyperproliferative changes in the rat colon during growth and maturity, especially the distal colon, as found in humans at risk for neoplasia.     

Epidemiologic characteristics of the flat adenoma of muto

The flat adenoma is an endoscopically visible lesion that histologically consists of adenomatous change near the luminal surface of colonic tubules. We have described three families with hereditary colon cancer with later age of onset than familial adenomatous polyposis (FAP) and with multiple proximal colonic flat adenomas. These families have been linked to the FAP locus on chromosome 5. Our aim was to determine whether the flat adenoma is pathognomonic of this hereditary flat adenoma syndrome (HFAS) or merely an atypical or early tubular adenoma with occurrence in patients other than those from colon cancer-prone families. Methods: We prospectively examined a population referred for colonoscopy within a one-year period. During colonoscopy, flat adenomas were specifically sought and all lesions were removed endoscopically and evaluated histologically. Members of known hereditary colon cancer families were excluded. Results: One hundred forty-eight patients underwent colonoscopy (64 men and 84 women). Median age was 61 years. Fifty-seven patients had 157 polyps. One hundred thirty-six polyps were reviewed histologically. Thirty-five (23.6 percent) of the referred patients had adenomas, of whom twelve patients had only flat adenomas while six had both flat and other adenomas (18=12 percent of 148). The associations between flat adenoma occurrence and various predictors (sex, race, prior colonic neoplasms, family history of cancer, synchronous adenomas) were similar to those seen with other adenomas. Flat adenomas were found in nearly equal proportions of patients under or over age 61 years (11 percent and 13 percent, respectively). Other adenomas were significantly more common in the older group (6 percent vs.25 percent;P <0.002 by Fisher's exact test). Conclusion: In a referral practice, the flat adenoma has the same prevalence and associated risk factors as other adenomas, except for younger age of onset. Our data suggest that the flat adenoma represents an early stage of adenoma development that is manifested in a subset of patients from the general population and that, as an isolated event, does not provide a marker for a hereditary colon cancer-prone syndrome.Supported in part by NCI Grant 5 ROI CA-42705.