Audit on flexible sigmoidoscopy for rectal bleeding in a district general hospital: are we over-loading the resources?

OBJECTIVE

Patients with rectal bleeding are being over investigated because of the fear of missing colorectal cancers. This study aimed to identify the percentage of patients <45 years of age who undergo flexible sigmoidoscopy for rectal bleeding, and to assess and compare the incidence of colorectal cancers and polyps above and below this age.

METHODS

Patients who underwent flexible sigmoidoscopy for rectal bleeding between 1 January 2000 and 31 December 2002 were reviewed. Patients were divided into two groups: group 1 consisted of patients aged >or=45 years and group 2 patients <45 years. The histopathology of biopsy specimens taken was also studied.

RESULTS

Altogether 18.9% of the patients who had flexible sigmoidoscopy for rectal bleeding were <45 years. The incidence of colorectal cancers in group 1 was 3.5%; all these cases were confirmed on histopathology. Only one patient in group 2 was diagnosed with colorectal cancer on flexible sigmoidoscopy, but the histopathology disproved it. The incidence of polyps was 16.6% in group 1 and 7.9% in group 2. Following histopathology, the incidence of adenomatous polyps was 6.8% in group 1 and 2.1% in group 2. There was a significant difference between the two groups, with a p value of <0.0001.

CONCLUSION

The incidence of colorectal cancers and adenomatous polyps in patients aged <45 years with rectal bleeding is very low. A flexible sigmoidoscopy costs approximately pound 330. If new guidelines are implemented considering the age of the patient, considerable cost savings could be made, and the available resources could be appropriately used in groups with high incidences of colorectal cancers.

High prevalence of hyperplastic colonic polyps in acromegalic subjects

We evaluated the prevalence and features of colonic polyps in a population of acromegalic subjects, compared to a control group of patients with irritable bowel syndrome (IBS). Colonic polyps were found in 30 acromegalic subjects (40%) and in 10 controls (13%) (P < 0.0001). Among the acromegalic patients, polyps were of the hyperplastic type in 27 subjects (90%) and adenomatous in 3 (10%). In the control group, polyps were hyperplastic in nine subjects (90%) and adenomatous in one (10%). We also observed a significant association (P < 0.0001) between the presence of hyperplastic polyps and the older age in both the acromegalic and the control groups. There were no differences between the two groups regarding sex, site, size, or macroscopic and histological types of polyps. Acromegalic patients have a higher prevalence of colonic hyperplastic polyps than IBS subjects, while the prevalence of adenomatous polyps is similar in the two groups.

["Tingling feet," forgetfulness, and progressive personality changes in a 63-year-old patient]

A 63-year-old female was admitted to the hospital with leg and forearm paresthesias. We found progressive ataxia, dementia, and psychosocial deterioration. The clinical symptoms, the neurologic and psychiatric abnormalities together with the inflammatory cerebrospinal fluid alteration and the cerebral magnetic resonance imaging changes suggested a paraneoplastic etiology. It was confirmed by paraneoplastic antineuronal antibodies in the patient's serum and the histological diagnosis of a small cell bronchial carcinoma. The prognosis of patients with paraneoplastic symptoms is the better the earlier a diagnosis is established and antitumor therapy is initiated.

Darmkrebs-Vorsorge im Betrieb

BACKGROUND AND OBJECTIVE

The annual incidence of colorectal cancer in Germany is estimated at 27000 in men and 30000 in women. If the diagnosis is made early the cure rate is over 90%. Against this background the department of occupational medicine and health protection of the BASF Aktiengesellschaft initiated a study on the potential prevention of colorectal cancer among the staff at its Ludwigshafen site.

SUBJECTS AND METHODS

The target group included all 13265 actively working employees aged 45 years or above. Those expressing interest were given a standardized questionnaire concerning risk factors for colorectal cancer and a test for occult fecal blood (FOBT). If the test was positive and/or a positive answer was given to the question on blood in the stool or on a positive family history, coloscopy - to be arranged via the general practitioner - was advised, in line with the recommendations of the German Society of Digestive and Metabolic diseases (Deutsche Gesellschaft für Verdauungs- und Stoffwechselerkrankungen).

RESULTS

At the end of the study 3732 employees (337 women, 3395 men, mean age 52 years) had completed the questionnaire and the FOBT results were available. Coloscopy was recommended to 688 employees, 323 of whom (47%) underwent the investigation. Nine of the subjects already had manifest cancer, six of them in the early stage T1 or T2. Adenomatous polyps were found in an additional 61 and subsequently excised. Cost-benefit considerations at the company level or in the area of the health system, respectively, gave favourable ratios of 1:10 and 1:14.

CONCLUSION

It requires considerable expenditure to increase the number of participants in the cancer prevention programme and obtain a consequent clarification of suspicious findings. Health care within a company is a valuable complementation in Germany of medical care provided by general practitioners or specialist, if close cooperation between practitioners in the given region is assured. Initiatives like the one presented here protect people personally affected against pain and distress and are also of economic value.

Colorectal cancer screening programme by faecal occult blood test in Tuscany: first round results

Screening with faecal occult blood test (FOBT) has been shown to be effective in reducing mortality from colorectal cancer. Tuscany was the first region in Italy in which a screening programme for colorectal cancer by FOBT was initiated region-wide. The aim of the paper was to describe organizational aspects, a quality control model and the results of this experience. From June 2000 to December 2001, 192583 subjects aged 50-70 were invited to undergo a 1-day immunochemical test without any dietary restriction. A total of 78505 subjects (41%) performed the screening test, of whom 4537 responders had a positive test result (5.8%). Among them, 1122 refused any form of assessment or underwent a colonoscopy outside the screening referral centres, with an overall assessment compliance of 75.3%. Malignancies were found in 193 patients and at least a high-risk adenomatous polyp in 692 patients. In about a quarter of the positive subjects who underwent assessment, cancer or high-risk adenoma was detected. In conclusion, data from this experience supported the feasibility of biennial colorectal screening programme by FOBT, particularly regarding invitation compliance and positivity rate. Further efforts are necessary to implement screening extension and to improve data collection.

Selektion von Patienten mit Rektumtumoren zur lokalen Exzision aufgrund der pr�operativen Diagnostik

INTRODUCTION

The aim of our study was to evaluate the accuracy of clinical staging (CS), biopsies, and endoluminal ultrasonic examination (EUS) in preoperative staging of rectal tumors treated with transanal local excision. This local excision is an adequate procedure for benign rectal polyps and low-risk T1 carcinoma.

PATIENTS AND METHODS

The study included 552 patients with rectal adenocarcinoma, villous adenoma, or tumors with other histologic characteristics who underwent a transanal excision (transanal endoscopic microsurgery n=513 or transanal excision n=39). We compared the results of CS, biopsies, and EUS with postoperative pathology findings.

RESULTS

Preoperative histological diagnosis of the rectal carcinoma depended on tumor size (52% in cancers <3 cm, 25% in cancers >3 cm; p=0.001) and was correct in 56% of cases. Transanal ultrasonography (uT0/1) had superior sensitivity (95% vs 78%) and a higher positive predictive value (93% vs 85%) than clinical staging (CS I) in detecting adenoma or T1 rectal carcinoma, whereas specificity was similar in both (62% vs 58%). In patients in whom preoperative histological analysis revealed adenomas, transanal ultrasonography was accurate (uT0/1) for the postoperatively assessed adenoma pT1 in 97%, whereas diagnosis (uT0/1) was correct in only 71% of cases in which preoperative histological analyses showed rectal carcinomas.

CONCLUSIONS

In patients with rectal tumors, preoperative staging with transanal ultrasonography and biopsy is essential for the indication and allows selection of patients for transanal local excision.

[Gastric epithelial polyps (part two)]

The following is a statistical report regarding gastric polyps: Frequency determined through endoscopic examinations was 3.6%. The terms hyperplastic polyps and adenomas were used for the classification of epithelial polyps, considering the suprafoveal hyperplasias within the hyperplastic polyps, provided they were elevated lesions. Out of 2,283 polyps, 1,959 were hyperplastic (86%) and 324 were adenomas (14%). When analyzing 780 polyps, 86 (11%) were found to have the Nakamura III category. With regard to topography, in an examination of 2253 polyps, hyperplastic polyps were located as follows: 325 (17%) in the antrum, 1402 (73%) in the body and 202 (10%) in the fundus. Adenomas had a different distribution: 212 (65%) in the antrum, 100 (31%) in the body and 12 (4%) in the fundus. Out of 371 hyperplastic polyps examined, 49% were pediculate and 51% were sessile; on the contrary, 86 % of adenomas were sessile. The average age was 66.2 years in adenoma carriers, 58.5 in those having hyperplastic polyps, and 57.4 for suprafoveal hyperplasias. In 287 adenomas, 94.1% of carriers were over 40 years old. Out of 92 adenomas examined, 21.7% evidenced adenoma metaplasia and 72.8% evidenced metaplasia in adjacent areas. Only 5.5% had no metaplasia. In 105 hyperplastic polyps studied, intestinal metaplasia was found: 16.7% in the polyp and 60% in adjacent areas. No metaplasia was found in the remaining 23.3%. Average size of the adenomas was 14 mm and of hyperplastic polyps, 11 mm. A total of 195 adenomas were smaller than 10 mm. The percentage of malignization in 288 adenomas examined was closely related to their size: 214 (66%) smaller than 20 mm, had a malignization percentage of 7%; 74 (34%) larger than 20 mm, had 51% malignization, and 86.2% malignization was found in adenomas of over 40 mm. Global malignization percentage of adenomas was 18%. However, when adenomas with high grade dysplasia in the 4.1 category of the Viena classification (non-invasive high grade neoplasia) were considered, this percentage rose to 26%. Malignization of hyperplastic polyps was 0.8%. When gastric acidity was determined using the maximum stimulation method, out of 77 cases of patients with hyperplastic polyps, 55 (60%) had real achlorhydria, 10 (18%) hypochlorhydria, 11 (20%) normochlorhydria, and only 1 (4) hyperchlorhydria. D.A.B. was 1.97 mEql for hyperplastics and 1.60 mEql for adenomas. D.A.M. was 6.05 mEql for hyperplastics and 5.49 mEql for adenomas. Our experience as to normal cases showed 2.5 mEqh +/- 1.2 and 22 mEqh +/- 6, respectively, for D.A.B and D.A.M.

Detection of murine intestinal adenomas using targeted molecular autofluorescence

There is a significant need for noninvasive methods of evaluating dysplastic and neoplastic lesions in the luminal gastrointestinal tract. We have optimized an approach based on autofluorescence to study dysplastic adenomatous polyps in Apc(min/+) mice. We made recordings from both normal intestinal mucosa and from polyps using a xenon lamp-based fiberoptic device. Seventy-eight polyps in 11 mice revealed an increase in mean autofluorescence intensity ratios of 1.29 +/- 0.04 (72 small intestinal polyps; P < 0.0001) and 1.28 +/- 0.05 (6 colon polyps; P = 0.0016). Serial measurements of autofluorescence discriminated polyps from normal mucosa with a sensitivity, verified histologically, of 95%. To understand the chemical basis for increased autofluorescence, we examined the tryptophan content of intestinal polyps and the adjacent normal mucosa in a small subset of animals. The findings revealed an increased concentration of tryptophan in polyps (990 +/- 240 ng/mg) compared to normal mucosa (720 +/- 150 ng/mg; P = 0.03). In conclusion, these findings suggest that autofluorescence intensity increases in the setting of intestinal neoplasia and can be used to detect adenomas in the mouse intestine in real time.

Prostatic epithelial polyp diagnosed in a bladder wash

Prostatic epithelial polyps, also known as adenomatous polyps or papillary adenomas with prostatic type epithelium, are uncommon lesions. These lesions typically involve the adult male urethra, trigone, or bladder dome. Diagnosis is usually made by biopsy. Presence of clusters of benign columnar cells in urine cytologic material can suggest the presence of such polyps and must be included in the differential diagnosis.

Metastatic Foci of Signet Ring Cell Carcinoma in a Tubular Adenoma of the Colon

We describe a case of adenomatous polyp of the colon that harbored small foci of signet ring cell carcinoma. The patient was a 64-year-old woman with end-stage renal disease and sepsis who underwent colonoscopy to evaluate the possibility of pseudomembranous colitis. A polyp was found incidentally in the right colon and a biopsy was performed. Histologic examination of the polyp revealed typical features of tubular adenoma without evidence of high-grade dysplasia. However, 2 small foci of signet ring cell carcinoma were identified that infiltrated the lamina propria. In contrast to adenomatous epithelium, the signet ring cells were immunohistochemically positive for cytokeratin 7 and negative for cytokeratin 20, suggesting a metastasis rather than a primary tumor. Multiple random biopsies from the right and left colon, as well as the ileum, exhibited no histologic evidence of malignancy. Subsequently, signet ring cell carcinoma with similar morphology and identical immunophenotype was detected in biopsies from the endometrium, an unusual location for primary signet ring cell carcinoma. Preliminary workup excluded the breast as a possible primary site, but further investigation was not possible because of the patient's death with no autopsy granted. To the best of our knowledge, this is the first reported case of metastatic signet ring cell carcinoma to an adenomatous polyp of the colon. This case illustrates the necessity of submitting all polyps entirely and the importance of examining them carefully.

Computer-aided tumor detection in endoscopic video using color wavelet features

We present an approach to the detection of tumors in colonoscopic video. It is based on a new color feature extraction scheme to represent the different regions in the frame sequence. This scheme is built on the wavelet decomposition. The features named as color wavelet covariance (CWC) are based on the covariances of second-order textural measures and an optimum subset of them is proposed after the application of a selection algorithm. The proposed approach is supported by a linear discriminant analysis (LDA) procedure for the characterization of the image regions along the video frames. The whole methodology has been applied on real data sets of color colonoscopic videos. The performance in the detection of abnormal colonic regions corresponding to adenomatous polyps has been estimated high, reaching 97% specificity and 90% sensitivity.

Brunner's gland polyp with upper gastrointestinal bleeding managed by endoscopic polypectomy: a report of two cases

We report 2 rare cases of Brunner's gland adenoma presenting with upper gastrointestinal bleeding. They were removed by endoscopic polypectomy. In skilled hands, this method is safe and effective.

Surveillance after positive and negative colonoscopy examinations: issues, yields, and use

As colorectal cancer screening gains acceptance by the public, the use of colonoscopy will increase. The frequency of surveillance examinations after detection of an adenoma is one of the largest contributors to the cost of colorectal cancer screening. Ten years after the publication of the landmark National Polyp Study, the issue of when to perform surveillance examinations and how often to expect advanced findings remains acute. Current guidelines for surveillance vary across specialty organizations. Individuals with advanced adenomas are at increased risk for recurrent advanced adenomas. The impact of multiple nonadvanced adenomas or a single nonadvanced adenoma on subsequent risk of an advanced adenoma or cancer is less clear. Still less is known about findings on repeat examinations after an initial negative examination, whether after colonoscopy or sigmoidoscopy. The yield after a negative examination is an important consideration in determining the recommended interval for screening colonoscopy. For example, the data supporting a 10-yr interval for screening colonoscopy is only indirect. What little we do know about the yield after negative examinations comes from selected, nonrepresentative populations. Of concern, evidence from several polyp prevention trials demonstrates higher yields for subsequent cancer than would be expected, despite a relatively high use of surveillance procedures in follow-up. Further population-based research on the frequency of use and yield of surveillance examinations is needed. Studies that examine the need and the needed timing of subsequent surveillance are essential to containing costs for screening as well as to informing the public better about what endoscopic screening can and cannot accomplish.

Computed tomography gastrography with volume-rendering technique: correlation with double-contrast barium study and conventional gastroscopy

The volume-rendering technique uses computed tomography data to produce simulated images of conventional barium and endoscopic studies of the stomach. Various gastric lesions are detected on volume-rendered images, and submucosal tumors are easily differentiated from mucosal lesions by means of the overlying bridging fold. Lesions that are only manifested by a change of mucosal color (early gastric cancer type 2b) or a loss of mucosal detail (gastritis) are difficult to detect from volume-rendered images, however. In cases of gastric neoplasm and varix, both the extraluminal pathologies of the lesion and the relation between the intraluminal and extraluminal components can be evaluated simultaneously.

Diagnostic potential of near-infrared Raman spectroscopy in the colon: differentiating adenomatous from hyperplastic polyps

BACKGROUND

Near-infrared Raman spectroscopy is a promising optical technique for GI tissue diagnosis. This study assessed the diagnostic potential of near-infrared Raman spectroscopy in the colon by evaluating its ability to distinguish between adenomatous and hyperplastic polyps.

METHODS

Ex vivo and in vivo Raman spectra of colon polyps were collected by using a custom-built, fiber-optic, near-infrared Raman spectroscopic system. Multivariate statistical techniques, including principal component analysis and linear discriminant analysis, were used to develop diagnostic algorithms for classifying colon polyps based on their spectral characteristics. With the number of samples available, spectral classification of polyps was tested by using a leave-one-out, cross-validation method.

RESULTS

Fifty-four ex vivo Raman spectra were analyzed (20 hyperplastic, 34 adenomatous). The spectral-based diagnostic algorithms identified adenomatous polyps with 91% sensitivity, 95% specificity, and 93% accuracy. In vivo, adenomas (n = 10) were distinguished from hyperplastic polyps (n = 9) with 100% sensitivity, 89% specificity, and 95% accuracy.

CONCLUSIONS

Near-infrared Raman spectroscopy differentiated adenomatous from hyperplastic polyps with high diagnostic accuracy. To our knowledge, this is the first demonstration of the potential of near-infrared Raman spectroscopy for differentiation of colonic polyps during GI endoscopy.

Detection of proximal adenomatous polyps with screening sigmoidoscopy: a systematic review and meta-analysis of screening colonoscopy

BACKGROUND

The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. To address this, we performed a systematic review and meta-analysis of screening colonoscopy studies.

METHODS

Published studies through July 31, 2000, of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. We generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia.

RESULTS

Using the sigmoid-descending colon junction to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [CI], 1.42-4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio, 2.36; 95% CI, 1.30-4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio, 1.44; 95% CI, 0.79-2.62). The prevalence of isolated advanced proximal neoplasia in the 3 studies was 2%, 3%, and 5%. Using the sigmoid-descending colon junction to identify the beginning of the distal colon yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI, 13.6%-19.1%).

CONCLUSIONS

Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increased prevalence of synchronous proximal neoplasia. Two percent to 5% of patients undergoing screening colonoscopy may have isolated advanced proximal neoplasia. Even more patients may have isolated nonadvanced proximal neoplasia.

Colonoscopic surveillance after surgery for colorectal cancer

BACKGROUND

Intensive colonoscopic surveillance after resection of colorectal cancer (CRC) has been shown not to improve outcome. The National Health and Medical Research Council of Australia (NHMRC) has recently published guidelines recommending appropriate surveillance intervals after CRC resection. The aims of the present study were to assess current and past patterns of postoperative CRC surveillance and to determine the yield of neoplasia from such surveillance.

METHODS

An audit was performed of all patients who underwent colonoscopy following surgical resection of CRC from 1989 to 2001. Two groups were assessed: (i) all patients undergoing surveillance colonoscopies; and (ii) all patients diagnosed with CRC at Sir Charles Gairdner Hospital (SCGH) who subsequently had postoperative colonoscopies. Patients who had their index colonoscopy at the study centre and who subsequently underwent surveillance colonoscopies were studied in detail. Yield for neoplasia, patterns of surveillance and concordance with NHMRC recommendations were determined.

RESULTS

There were 990 surveillance examinations performed and colorectal adenomas were identified in 184. However, only one case of recurrent cancer was detected. There were a total of 161 patients who had CRC diagnosed and underwent surveillance at SCGH. Of these patients, 75% underwent colonoscopy at 12 months after resection and 48% of these cases underwent a further examination within 12 months. Only 23% of examinations concurred with NHMRC recommendations and practice has not changed with release of these guidelines.

CONCLUSIONS

Resectable CRC recurrences are rarely detected at colonoscopic surveillance. Surveillance colonoscopies are -performed too frequently and release of NHMRC guidelines has failed to change practice.

American Cancer Society guidelines for the early detection of cancer, 2003

Each January, the American Cancer Society (ACS) publishes a summary of existing recommendations for early cancer detection, including updates, and/or emerging issues that are relevant to screening for cancer. In 2002, the ACS assembled expert groups to update guidelines for cervical cancer screening and breast cancer screening, and to evaluate new technology for colorectal cancer screening. In November 2002, updated guidelines for cervical cancer screening were published in this journal, and breast cancer screening guidelines will be updated in 2003. In this issue, there is a report of a workshop held to review emerging technology for colorectal cancer screening that resulted in a modification of current previous recommendations for fecal occult blood tests, and revised recommendations for the "cancer-related check-up" in which clinical encounters provide case-finding and health-counseling opportunities. Finally, we provide an update of the most recent data pertaining to participation rates in cancer screening by age, gender, and ethnicity from the Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS).

Colon polyps and cancer

A large number of studies published last year in peer-reviewed medical journals help to better define the advantages and limitations of the different options for colorectal cancer screening. Direct colonoscopy screening appears to have the greatest potential to markedly reduce both the incidence and mortality of colorectal cancer, but many obstacles limiting its widespread use in the general at-risk population still exist, and many questions remain incompletely answered. Recent studies stress the fact that finding and resecting advanced adenomatous polyps, and thereby preventing cancer, is becoming a primary objective of screening programs. Several papers also show the potential of emerging new methods of screening for specific markers in stool and for imaging the colon with computed-tomographic colonography (virtual colonoscopy). Other important publications highlighted in this review deal with the diagnosis of colorectal neoplasia, familial colorectal cancer, colorectal polyps and the adenoma-carcinoma sequence, and new and novel methods of improving the efficiency and safety of colonoscopic polypectomy.

Emerging technologies in screening for colorectal cancer: CT colonography, immunochemical fecal occult blood tests, and stool screening using molecular markers

The American Cancer Society's (ACS) Colorectal Cancer Advisory Group held a workshop on new technologies for the early detection of colorectal cancer and adenomatous polyps as part of a regular review of ACS guidelines for colorectal cancer screening. The Advisory Group formally reviewed CT colonography, immunochemical fecal occult blood tests (FOBT), and stool screening using molecular markers, and also addressed other technologies including capsule video endoscopy. With the exception of immunochemical stool testing, the ACS has determined that at this time there is insufficient evidence to recommend these technologies for routine colorectal cancer screening. Based on recommendations of the Advisory Group, only a minor modification has been made to the ACS's Recommendations for Screening and Surveillance of the Early Detection of Adenomatous Polyps and Colorectal Cancer.

The role of endoscopic colon surveillance in the transplant population

PURPOSE

Long-term immunosuppression increases the risks of developing certain malignancies. This study examines the effects of long-term immunosuppression on the development of metachronous adenomatous polyps and attempts to formulate a sound surveillance plan for these individuals.

METHOD

A retrospective analysis was performed of all solid organ transplant patients at Henry Ford Hospital from 1989 to 1999, with a specific focus on endoscopic evaluation and outcomes after three years of surveillance. Comparison was made to an age-matched and gender-matched control group from the same endoscopic database. Variables were compared using the chi-squared test, Fisher's exact probability test, and Hochberg's test.

RESULTS

A total of 992 solid organ transplants were performed. Two hundred twenty-nine (23 percent) of the transplant recipients underwent pretransplant colonoscopy, of which 178 patients (78 percent) were age 50 years or older. Seventy-four (32 percent) of the prescreened population had polyps, of which 45 patients (61 percent) had adenomas. Twenty-seven patients (36 percent) had synchronous polyps, of which 12 patients (16 percent) had synchronous adenomas. At 3-year follow-up 59 patients (80 percent) had metachronous polyps. Twenty-eight patients (38 percent) had metachronous adenomas. Eleven patients (15 percent) with hyperplastic polyps on initial colonoscopy developed adenomas. The control group consisted of 25 females and 50 males with a mean age of 65.5 +/- 1.1 years. Fifty-one patients (68 percent) had adenomas on endoscopy. Twenty-four patients (32 percent) had synchronous lesions, of which 13 patients (17 percent) had synchronous adenomas. Sixty-one patients (84 percent) developed metachronous lesions, of which 33 patients (43 percent) had metachronous adenomas at 3 years. There was no difference in the polyp size or histology between the two groups. There was no statistically significant difference between the transplant patients and the control group in all analyses.

CONCLUSION

Because of an equivalent incidence of adenomatous polyps compared with the general population, current screening criteria should be used in patients posttransplant. Transplant patients are not more likely to develop metachronous polyps than the general population. Therefore, posttransplant polyp surveillance should not be more frequent than currently recommended for nontransplant patients with adenomatous polyps.

Promoting early detection tests for colorectal carcinoma and adenomatous polyps: a framework for action: the strategic plan of the National Colorectal Cancer Roundtable

BACKGROUND

The purpose of the current study was to provide health professionals, professional organizations, policy makers, and the general public with a practical blueprint for increasing the practice of screening for colorectal carcinoma (CRC) and adenomatous polyps over the next decade. The National Colorectal Cancer Roundtable (NCCRT) was founded in 1997 by the American Cancer Society and the Centers for Disease Control and Prevention to provide strategic leadership, advocacy, long-range planning, and coordination of interventions targeted at reducing the disease burden of CRC through education, early detection, and prevention. The NCCRT and its three workgroups include CRC survivors; recognized experts in primary care, gastroenterology, radiology, colorectal surgery, nursing, public policy, epidemiology, and behavioral science; patient advocates; and representatives of health plans and insurers, government, and other organizations.

METHODS

The NCCRT performed a literature review of published and unpublished data related to CRC screening guidelines, compliance, and barriers to adherence, as well as test effectiveness and cost-effectiveness. Members of the three NCCRT workgroups developed summary reports regarding professional education, public education and awareness, and health policy. A drafting committee developed the final strategic plan from workgroup reports, which was reviewed by the entire NCCRT membership, amended, and subsequently approved in final form.

RESULTS AND CONCLUSIONS

Although the rationale for population-wide CRC screening is well established, the majority of adults in the U.S. are not currently being screened for CRC. Thus, the nation foregoes an opportunity to reduce CRC-related mortality by an estimated >or= 50%. To increase CRC screening rates, the issues of patient and physician barriers to screening, lack of universal coverage, lack of incentives to motivate adherence, and expanded infrastructure must be addressed.

[Screening for colorectal carcinoma in the region surrounding the city of Frýdek-Místek between 1999 - 2001]

The results of the colorectal carcinoma screening project in the region of Frýdek-Místek for the period of 1999 - 2001 are presented here. Of the 225 patiens diagnosed with carcinoma, 9 of the cases (4 %) were detected using the fecal occult bleeding test. Of 1000 people tested, a factor of 2.9 patients with carcinoma and 12.5 patients with adenomatous polyps were diagnosed, with 7.3 % test positivity. A statistically significant shift has been noted to detection in earlier stages of the disease (p = 0.05). From 49 - 53 % of the patients operated on in the period of 1999 - 2001 had their tumors in the stage A or B according to Dukes, a 13 - 17 % increase over the year of 1998. This shift was due above all to educating the local population.

Diagnostic potential of Fourier-transform infrared microspectroscopy and advanced computational methods in colon cancer patients

Colon cancer is the third leading class of cancer causing increased mortality in developed countries. A polyp is one type of lesion observed in a majority of colon cancer patients. Here, we report a microscopic Fourier transform infrared (FTIR) study of normal, adenomatous polyp and malignant cells from biopsies of 24 patients. The goal of our study was to differentiate an adenomatous polyp from a malignant cell using FTIR microspectroscopy and artificial neural network (ANN) analysis. FTIR spectra and biological markers such as phosphate, RNA/DNA derived from spectra, were useful in identifying normal cells from abnormal ones that consisted of adenomatous polyp and malignant cells. However, the biological markers failed to differentiate between adenomatous polyp and malignant cases. By employing a combination of wavelet features and an ANN based classifier, we were able to classify the different cells as normal, adenomatous polyp and cancerous in a given tissue sample. The percentage of success of classification was 89%, 81%, and 83% for normal, adenomatous polyp, and malignant cells, respectively. A comparison of the method proposed with the pathological method is also discussed.

Artificial neural networks distinguish among subtypes of neoplastic colorectal lesions

BACKGROUND & AIMS

There is a subtle distinction between sporadic colorectal adenomas and cancers (SAC) and inflammatory bowel disease (IBD)-associated dysplasias and cancers. However, this distinction is clinically important because sporadic adenomas are usually managed by polypectomy alone, whereas IBD-related high-grade dysplasias mandate subtotal colectomy. The current study evaluated the ability of artificial neural networks (ANNs) based on complementary DNA (cDNA) microarray data to discriminate between these 2 types of colorectal lesions.

METHODS

We hybridized cDNA microarrays, each containing 8064 cDNA clones, to RNAs derived from 39 colorectal neoplastic specimens. Hierarchical clustering was performed, and an ANN was constructed and trained on a set of 5 IBD-related dysplasia or cancer (IBDNs) and 22 SACs.

RESULTS

Hierarchical clustering based on all 8064 clones failed to correctly categorize the SACs and IBDNs. However, the ANN correctly diagnosed 12 of 12 blinded samples in a test set (3 IBDNs and 9 SACs). Furthermore, using an iterative process based on the computer programs GeneFinder, Cluster, and MATLAB, we reduced the number of clones used for diagnosis from 8064 to 97. Even with this reduced clone set, the ANN retained its capacity for correct diagnosis. Moreover, cluster analysis performed with these 97 clones now separated the 2 types of lesions.

CONCLUSIONS

Our results suggest that ANNs have the potential to discriminate among subtly different clinical entities, such as IBDNs and SACs, as well as to identify gene subsets having the power to make these diagnostic distinctions.

Synchronous proximal polyps and cancer in patients with polyps detected at sigmoidoscopy: results of a single, rural-based sigmoidoscopy clinic

The prevalence of polyps and cancer in the proximal colon among patients who have polyps detected on sigmoidoscopy was determined in a large rural referral hospital in north central Pennsylvania. Eleven thousand one hundred sixty patients underwent sigmoidoscopy between 1991 and 1997. Polyps were detected in 709 patients. Five hundred twenty-three patients who had a polyp at sigmoidoscopy and full colonoscopy completed within one year were included in this study. 120 patients (23%) had a proximal polyp detected at colonoscopy. The prevalence of proximal polyps and histologically advanced polyps was related to the size, number, and histology of the distal index polyp found at sigmoidoscopy. However, the absolute difference in prevalence of proximal polyps stratified by dings at sigmoidoscopy was small. A total of 5 adenocarcinomas were detected in the proximal colon. All proximal cancers detected at colonoscopy occurred in patients with a distal polyp less than 10 mm. Our data emphasize the importance of colonoscopy in all patients with a polyp detected at sigmoidoscopy independent of its size and histology.

The case for population-based screening for colorectal cancer

Screening for colorectal cancer is commanding increasing attention. Other cancer screening programmes have been a part of public consciousness for some time, but, until recently, colorectal cancer screening has remained in the background. Fuelled by new research, market opportunities and increased recognition of individual risk, screening for colorectal cancer is becoming a recommended procedure, but controversy about how best to implement widespread screening remains.

Investigating chronic, bright red, rectal bleeding

BACKGROUND

Chronic, bright red, rectal bleeding is a common symptom in our community and the aetiology is frequently benign anal disease. The aim of the present study was to determine the efficacy of performing a flexible sigmoidoscopy on patients with chronic, bright red, rectal bleeding who are at low risk for colorectal neoplasia and who, on rigid sigmoidoscopy, are found to have an identifiable anal cause (e.g. haemorrhoids, fissure) for their bleeding.

METHODS

A prospective study was conducted on patients presenting with chronic, bright red, rectal bleeding. Patients were considered at low risk for colorectal neoplasia if they fulfilled the following criteria: (i) less than 55 years of age; (ii) no past or family history of colorectal neoplasia or inflammatory bowel disease; (iii) no symptoms of altered bowel habit or abdominal pain; and (iv) a source of bleeding identified (e.g. haemorrhoids, fissure) on rigid sigmoidoscopy. All patients underwent a flexible sigmoidoscopy.

RESULTS

Eighty-two patients were entered into the trial, mean age 39 +/- 9 years (range: 22-55 years), and the ratio of men:women was 1.8:1. The anal cause of bleeding was haemorrhoids in 96%, and anal fissure in 4%. At flexible sigmoidoscopy, five patients were found to have adenomatous polyps. Rigid sigmoidoscopy missed diminutive neoplastic lesions in 6% of patients.

CONCLUSIONS

Flexible sigmoidoscopy results in a low yield of colorectal neoplasia in patients presenting with chronic, bright red, rectal bleeding who are at low risk for colorectal neoplasia and who have an identifiable anal cause for their bleeding.

[Colonoscopic follow-up of patients undergoing curative resection of colorectal cancer]

AIM

To investigate the role of colonoscopy in the follow-up of patients undergoing curative resection of colorectal cancer.

MATERIAL AND METHODS

A prospective study was performed of 102 patients with colorectal cancer who underwent surgery with curative intention. Postoperative colonoscopic follow-up was a minimum of 5 years.

RESULTS

There were 62 males and 40 females. The mean duration of follow-up was 73.4 months. Synchronous polyps were found in 44.1% (114 in 45 patients) and metachronous polyps in 33.4% (64 in 34 patients). Synchronous carcinoma was detected in 7.8% (9 in 8 patients), metachronous carcinoma in 1.9% (2 in 2 patients) and suture recurrence in 4.9% (5 in 5 patients). Metachronous polyps developed in 55.5% of the patients with synchronous polyps and in only 15.8% of those with no synchronous polyps (p < 0.00005); the odds ratio was 6.67. Colonoscopy diagnosed 92 synchronous polyps and 64 metachronous polyps; of these, 34 were found to be significant(in 22 patients). Colonoscopy diagnosed 5 synchronous carcinomas; in 3 of these (polyps with non-invasive carcinoma) polypectomy constituted definitive therapy and in the remaining 2, curative resection was achieved. Colonoscopy diagnosed 2 stage C2 metachronous carcinomas at 63 and 94 months. Curative resection was achieved in both cases. Colonoscopic follow-up diagnosed 2 suture recurrences and resection was potentially curative.

CONCLUSIONS

Colonoscopy was found to play an essential role in 30% of the patients. The technique allowed the early diagnosis of synchronous carcinomas and curative treatment of metachronous carcinomas and demonstrated that the presence of synchronous polyps increases the risk of developing metachronous polyps.

[Revised CBO guideline 'Follow-up after polypectomy']

The purpose of follow-up after polypectomy of one or more colorectal adenomatous polyps, is the timely removal of new adenomas and thereby the prevention of colorectal cancer. The first check-up following index-polypectomy can be carried out after six years if one or two adenomas were encountered during the index polypectomy, and after three years if three or more adenomas were encountered. The same check-up interval of six and three years respectively applies if none to two or more than three adenomas are encountered when a check-up colonoscopy is carried out. A check-up one year after the polypectomy and check-ups more frequently than respectively six and three years after polypectomy are not considered to be useful, while each check-up is accompanied by risks and costs. Check-ups can be suspended for patients in whom cumulatively one adenomatous polyp has been removed: from the age of 65 years, for patients in whom cumulatively two adenomas have been removed: from the age of 75 years, and for patients in whom cumulatively three adenomas have been removed check-ups must be continued for as long as the patient's vitality justifies this. Also if no adenomas are encountered during three consecutive check-ups, a suspension of the check-ups can be considered. Separate guidelines apply to patients with genetically determined adenomas.

The anatomical distribution of colorectal polyps at colonoscopy

BACKGROUND

Colorectal carcinoma is one of the most common causes of cancer-related deaths in Australia. The distribution of polyps in the colon may effect the efficacy of a screening modality. The aim of this study was to determine the age-matched anatomic location and histologic type of colorectal polyps observed at colonoscopy over a 10-year period at our endoscopy unit.

STUDY

Endoscopy reports on 2,578 patients were reviewed; polyp/lesion histology and location (left, right, or both) were determined in 2,553.

RESULTS

Of all polyps observed, 1,310 (51%) cases were left-sided, 510 (20%) were right-sided, and 733 (29%) were synchronous. Adenomas were present in 1,659 cases (65%); of these, 734 (44%) were left-sided only and 405 (24.5%) were right-sided only. Carcinoma was observed in 189 (7%) cases, of which 71 (37.5%) were left-sided only. There was an increased right-sided prevalence of adenoma or carcinoma with age (p = 0.0029).

CONCLUSION

This was not a screening study, but it has shown that a significant number of adenomas and carcinomas lie proximal to the splenic flexure. Thus, in the absence of left-sided lesions, it is expected that examination of the colon limited to the splenic flexure would miss 23% of such lesions. The increasing right-sided prevalence of these lesions with age suggests that evaluation of the proximal bowel is particularly important in older people.

18F-FDG PET detection of colonic adenomas

The adenomatous polyp of the colon is clinically important as a precursor of colonic cancer. The aim of this preliminary study was to evaluate the potential usefulness of (18)F-FDG PET for detecting adenomatous polyps of the colon.

METHODS

We performed a retrospective study of 110 subjects who underwent both PET study and total colonoscopy. On nonattenuation-corrected PET images, focal distinct FDG accumulation along the large intestine was considered a positive finding, and the PET results were compared with colonoscopic findings. Histology and adenoma size were determined by polypectomy.

RESULTS

Fifty-nine adenomatous polyps, 5-30 mm in size, were found in 30 subjects by total colonoscopy. PET findings were positive for 14 of the 59 adenomas (24%). The positivity rate for PET images rose with the increase in size of the adenomas; it was 90% in adenomas (9/10) that were > or =13 mm. The overall false-positive rate was 5.5% (6/110 subjects).

CONCLUSION

Increased glucose metabolism is observed in colonic adenomas, and detectability with PET increases with the increase in adenoma size. Adenomas are premalignant lesions, and it is important to realize that colonic adenomas may be found incidentally during an FDG PET study.

Increased incidence of colorectal adenomas in follow-up evaluation of patients with newly diagnosed hyperplastic polyps

BACKGROUND

Although adenomatous polyps have been established clearly as precursor lesions for most cases of colorectal cancer, the role, if any, of hyperplastic polyps remains uncertain. The aim of the current study was to determine whether a patient with an index finding of hyperplastic polyp on colonoscopy is at increased risk for adenomatous polyps.

METHODS

We conducted a retrospective cohort study using the records of a single surgeon's colonoscopic experience over a 20-year period (June 1973 to December 1994). Patients found to have hyperplastic lesions on index colonoscopy were compared with those who had "clean" index colonoscopies. The two groups were compared for the subsequent diagnosis of adenomatous polyps on follow-up colonoscopies. Those with cancer or adenomas at index colonoscopy or in their history were excluded. We used Cox proportional hazard modeling with subsequent adenoma or cancer diagnosis at follow-up colonoscopy as the outcome, controlling for age and gender.

RESULTS

We identified 42 patients for whom hyperplastic polyps were the only colorectal neoplasms found on the index examination, in contrast to 362 control patients who had a "clean" index examination. In this cohort study, patients found to have only hyperplastic polyps on initial examination had a rate of subsequent adenoma diagnoses (42%) twice that of patients with a clean initial colonoscopy (21%). Mean follow-up time was 4.3 years. The relative rate ratio was 2.0 (95% confidence interval, 1.2-3.4).

CONCLUSIONS

This study suggests that patients found to have hyperplastic polyps on initial colonoscopic examination may have twice the risk of adenomas on follow-up colonoscopy, as compared with those who have clean initial examinations. If this finding is borne out in larger prospective studies, surveillance strategies may need to be modified accordingly.

Fecal occult blood and flexible sigmoidoscopy screening for colorectal cancer: modeling the impact on colonoscopy requirements and cancer detection rates

AIM

The aim of this study was to estimate the colonoscopy requirements and the likely impact of fecal occult blood and flexible sigmoidoscopy screening on the detection of colorectal cancer by using previously published data.

METHODS

Fecal occult blood and flexible sigmoidoscopy screening programs were applied to the 2.04 million subjects aged 50-65 years, at a participation rate of 40%. The following strategies were evaluated: Fecal occult blood testing with colonoscopy follow up of all positive tests; flexible sigmoidoscopy with colonoscopy follow up of all adenomatous polyps; and flexible sigmoidoscopy with colonoscopy follow up of all adenomatous polyps > 10 mm in size.

RESULTS

The fecal occult blood program detected 5.6% of all colorectal cancer cases at a rate of 2,914 colonoscopies/percentage of detection of colorectal cancer. The flexible sigmoidoscopy program detected 14% of all colorectal cancer cases at a rate of 8,160 colonoscopies/percentage of detection of colorectal cancer. The flexible sigmoidoscopy program with follow up of adenomatous polyps > 10 mm in size detected 13% of all colorectal cancer cases at a rate of 1,230 colonoscopies/percentage of detection of colorectal cancer.

CONCLUSIONS

Flexible sigmoidoscopy screening followed by colonoscopic follow up of adenomatous polyps > 10 mm in size is the most efficient screening strategy in terms of colonoscopies generated and cases of colorectal cancer detected.

Adenomatous polyps develop commonly in the ileal pouch of patients with familial adenomatous polyposis

PURPOSE

The aim of this study was to establish the prevalence of adenomatous polyps in the ileal pouch of patients with familial adenomatous polyposis.

METHOD

Forty-three patients who had an ileal pouch for familial adenomatous polyposis were invited to have a careful endoscopic examination of their pouch, including dye spraying. The number of polyps was recorded, and up to ten were biopsied. In addition, four random biopsy specimens were taken from the proximal and four from the distal pouch.

RESULTS

Thirty-three patients with a median age of 36 (range, 14-63) years who had a pouch (5 Kock and 28 pelvic) for a median of 7 (range, 1-19) years accepted the invitation. Twenty-one patients (64 percent) had endoscopically identified polyps, the number of polyps ranging from 1 to 100 (median, 10) and varying in size from 1 to 3 mm. Fourteen patients (42 percent) had adenomatous polyps and 4 of these also had microadenomas on random biopsies. Nine of the 14 patients with adenomas also had lymphoid polyps. Seven patients had lymphoid polyps only and two of these patients had a microadenoma on random biopsy. Four of 12 patients with no visible polyps had microadenomas in their random biopsies. The presence of adenomatous polyps (Pearson's correlation; P < 0.01) increased with the age of the pouch. In total, 20 of 33 (60 percent) patients had adenomas and or microadenomas.

CONCLUSION

Adenomatous polyps occur frequently in ileal pouches. These findings are of concern, and therefore, regular surveillance seems warranted until the natural history of these adenomatous polyps is determined.

Clinical evidence for the adenoma-carcinoma sequence, and the management of patients with colorectal adenomas

A large body of clinical evidence supports the belief that over 95% of colorectal cancers arise in benign adenomatous polyps that develop and grow very slowly over many years. Interruption of the adenoma-carcinoma sequence by resecting adenomatous polyps is a powerful method of secondary prevention of colorectal cancer. Colonoscopy is the procedure of choice for the diagnosis and resection of colorectal polyps. Patients who have had colonoscopic resection of adenomas, and in some cases their close relatives, are at increased risk for developing metachronous polyps and cancer and may benefit from follow-up colonoscopic surveillance. This surveillance should be individually tailored to the perceived risk of each case depending on the features of the adenomas removed and other patient factors such as family history. Widespread adoption of current postpolypectomy guideline recommendations is protective and conserves medical resources.

Improving outcomes in colonic cancer

Many of the symptoms of colon cancer do not start until the tumour has spread outside the bowel, and treatment at this stage has reduced chances of cure. Early detection and the optimum combination of surgery and adjuvant treatment can make a significant impact on outcome.