Francis A. Farraye

Is Colonoscopy Indicated for Small Adenomas Found by Screening Flexible Sigmoidoscopy

Several studies have shown that screening for colorectal cancer by fecal occult blood testing and lower endoscopy with removal of polyps reduces the mortality rate associated with colorectal cancer [1-3]. One recommended method of screening low-risk patients for colorectal cancer is the use of flexible sigmoidoscopy to detect neoplastic (adenomatous or cancerous) polyps. Many health organizations recommend that asymptomatic persons older than 50 years of age be screened for colorectal cancer with fecal occult blood testing and flexible sigmoidoscopy. This practice has become standard at many centers in the United States [4-7]. Flexible sigmoidoscopy is simple to perform, is well tolerated by patients, and is less expensive than colonoscopy. Other studies have shown that patients with adenomatous polyps in the distal colon are at increased risk for adenomatous polyps in the proximal colon [8-10]. Thus, it is accepted practice to recommend a full colonoscopy with examination of the proximal colon for all patients with adenomas in the distal colon. Studies comparing the natural history of small and large colonic adenomas have suggested that small (<1 cm) polyps have a lower risk for subsequent malignant transformation than do larger polyps [11, 12]. Other studies support the observation that small polyps are unlikely to be malignant or to have high-grade histologic features [13]. As data have accumulated on screening low-risk patients with flexible sigmoidoscopy, some investigators have noted a low prevalence (0.0% to 0.8%) of histologically advanced polyps in the proximal colon among patients with small distal tubular adenomas [9, 14]. Two other retrospective studies [15, 16] suggested that the long-term risk for colon cancer in the proximal colon among patients with small polyps in the distal colon is low. Other investigators [17] reported higher rates of advanced polyps in the proximal colon among patients with small distal adenomas, but this study included patients who had small tubular and villous adenomas on flexible sigmoidoscopy. Thus, estimates of the prevalence of advanced proximal polyps among patients with small adenomas detected by flexible sigmoidoscopy currently conflict. We sought to determine the prevalence of advanced adenomatous polyps in the proximal colon among patients with small tubular adenomas found on flexible sigmoidoscopy. We used a large prospective cohort of average-risk patients undergoing screening for colorectal cancer. Methods Patients Data were collected prospectively on flexible sigmoidoscopic examinations performed in 4490 patients as part of a colon cancer screening program at a large urban Veterans Affairs medical center and a health maintenance organization from 1992 to 1996. Baseline variables were collected on a standardized data form and included family history of colorectal cancer in first- and second-degree relatives, age at diagnosis, history of blood in the stool, and previous endoscopy. Flexible sigmoidoscopy was offered to patients referred by a primary care provider for colorectal cancer screening who were asymptomatic, were older than 50 years of age, did not have a first-degree relative 55 years of age or younger with colon cancer, had a negative result on a fecal occult blood test, and had not had previous barium enema or colonoscopy. Patients were prepared for screening by administration of two phosphosoda enemas on the morning of the examination. Examinations were performed by a trained physician assistant, nurse practitioner, or gastroenterology fellow under the supervision of a staff gastroenterologist. An endoscope was inserted to a depth of 60 cm or until solid stool was encountered. All polyps smaller than 10 mm identified by flexible sigmoidoscopy were biopsied and examined histologically. Patients with polyps larger than 10 mm on flexible sigmoidoscopy either underwent biopsy or were referred directly for colonoscopy (during which the polyp was removed). Polyps were characterized as non-neoplastic (normal mucosa, hyperplastic, or inflammatory) or neoplastic (tubular adenoma, tubulovillous adenoma, villous adenoma, high-grade dysplasia, or adenocarcinoma) by a gastrointestinal pathologist. The size of the polyp was estimated to the nearest millimeter by using an open biopsy forceps placed in direct contact with the polyp before polyp removal. All patients with neoplastic polyps were offered colonoscopy. Patients with single small adenomas (1 to 5 mm) were advised of the controversy over the implications of a single small distal adenoma found on flexible sigmoidoscopy. Colonoscopy was performed within 6 months of flexible sigmoidoscopy. Patients were prepared for colonoscopy by administration of polyethylene glycol-electrolyte gastrointestinal lavage or oral phosphosoda. All colonoscopies were performed by staff gastroenterologists or gastroenterology fellows under the supervision of a staff gastroenterologist. If a polyp was encountered, its location was estimated according to the distance from the anal verge as measured with markings on the endoscope. Polyp size was estimated to the nearest millimeter according to the methods described above. All visualized polyps were removed and characterized histologically. Polyps were considered advanced if they were larger than 10 mm or were characterized as tubulovillous, villous, high-grade dysplasia, or adenocarcinoma. Patients were prospectively subgrouped according to the number (1 or >1), size (1 to 5 mm, 6 to 10 mm, or >10 mm), and histologic characteristics (nonadvanced or advanced) of distal neoplastic polyps. Proximal neoplastic polyps were defined as those that were identified by colonoscopy (but not flexible sigmoidoscopy) and were proximal to the sigmoid-descending colon junction. Statistical Analysis The prevalence of advanced proximal polyps was determined, and subgroup analysis was performed on the basis of the size and number of neoplastic polyps found in the distal colon by flexible sigmoidoscopy. Confidence intervals for the prevalence rates were calculated by using exact methods for binomial data [18]. A chi-square test for linear trend was used to determine whether the three categories of distal polyps (single 1 to 5 mm, multiple or 6 to 10 mm, or advanced) showed an increasing association with advanced proximal polyps. Logistic regression analysis was performed by using S-Plus software (Statistical Sciences, Inc., Seattle, Washington) to evaluate for confounding by age and sex. Differences between patients with a distal neoplastic polyp who did or did not undergo colonoscopy were compared by using the Student t-test for continuous variables and the z-test for categorical variables. All tests were two-sided. The costs and consequences of the screening evaluation were determined by creating a decision model in DATA Software (TreeAge Inc., Williamstown, Massachusetts). Cost data for colonoscopy, biopsy, polypectomy, and flexible sigmoidoscopy were obtained from the Agency for Health Care Policy and Research publication on colorectal cancer screening [6]. The likelihood of having a polyp was taken directly from the observed data in the study. An estimate of the prevalence of proximal polyps among patients with no distal adenomas was obtained from the study by Rex and colleagues [19]. To include the observed data and 95% CIs, sensitivity analysis was performed on the prevalence of advanced proximal polyps among patients with tubular adenomas 1 to 5 mm in diameter on flexible sigmoidoscopy. Role of Funding Source The Harvard Pilgrim Health Care Foundation, the source of funding for this study, did not participate in data collection, analysis, or publication of this study. Results A neoplastic polyp was detected in 401 of 4490 asymptomatic patients who underwent flexible sigmoidoscopy, did not have first-degree relatives younger than 55 years of age with colorectal cancer, and had a negative result on a fecal occult blood test. Data on the size, location, and histologic characteristics of all polyps was complete for 392 patients (98%). Nine patients were excluded because of incomplete data (polyp was resected but not recovered for pathologic analysis [n = 6]) or polyp size was not reported [n = 3]). The mean age (SD) of patients with neoplasia was 62.5 8.1 years; 71% were male, and 29% were female. The histologic characteristics and size of the most advanced neoplastic polyps detected by flexible sigmoidoscopy among patients who had subsequent complete colonic visualization is shown in Table 1. Table 1. Histology and Size of Distal Polyps Detected on Flexible Sigmoidoscopy All 392 patients with distal neoplastic polyps were offered colonoscopy, and 301 (77%) agreed to undergo the procedure. All of the 91 patients who did not undergo colonoscopy had tubular adenomas. Eighty-six patients had a single adenoma 1 to 5 mm in diameter, 2 had multiple adenomas 1 to 5 mm in diameter, 2 had a single adenoma 6 to 10 mm in diameter, and 1 had multiple adenomas 6 to 10 mm in diameter. No patient with advanced distal adenomas refused colonoscopy. To look for potential bias between patients who did or did not undergo colonoscopy for a tubular adenoma 1 to 5 mm in diameter found by flexible sigmoidoscopy, we compared the mean age, presence of a family history of colorectal cancer other than in a first-degree relative younger than 55 years of age, and the site at which flexible sigmoidoscopy was performed (Veterans Affairs medical center or health maintenance organization). Patients who did and patients who did not undergo colonoscopy for a tubular adenoma 1 to 5 mm in diameter did not differ for age or family history of colorectal cancer (data not shown). Acceptance of a recommendation for colonoscopy differed significantly by the site at which flexible sigmoidoscopy was done. Among patients with distal adenomas, the Veterans Affairs medical center completed colonoscopy in 56 of 58 patients (96.6%) and the health

Screening for colorectal cancer with flexible sigmoidoscopy by nonphysician endoscopists.

PURPOSE Screening with sigmoidoscopy reduces the risk of death from colorectal cancer. Only 30% of eligible patients have undergone sigmoidoscopy, in part because of a limited supply of endoscopists. We evaluated the performance and safety of screening sigmoidoscopic examinations by trained nonphysician endoscopists in comparison with board-certified gastroenterologists. SUBJECTS AND METHODS Asymptomatic patients 50 years or older without evidence of fecal occult blood and no personal history or family history of a first-degree relative with colorectal cancer under age 55 years were offered sigmoidoscopy. All examinations were performed either by a gastroenterologist or a trained nonphysician endoscopist at a staff model health maintenance organization. Outcomes included the depth of examination, number and histology of polyps, and complications. RESULTS Nonphysicians performed 2,323 sigmoidoscopic examinations, and physicians performed 1,378 examinations. The mean (+/-SD) depth of sigmoidoscopy examinations performed by nonphysicians was 52 +/- 10 cm compared with 55 +/- 9 cm (P <0.001) in physicians. Nonphysicians detected neoplastic polyps in a greater proportion of patients (7.8%) than physicians (5.8%), but this difference was not significant after adjusting for differences in the age, sex, and family history of the patients (P = 0.35). No major complications occurred. The cost per examination, including the nonphysician training cost, was lower for nonphysicians (

The association between the myelodysplastic syndromes and Crohn disease.

186 per examination) than for physicians (

Training of nurse practitioners and physician assistants to perform screening flexible sigmoidoscopy.

283 per examination). CONCLUSIONS Appropriately trained nonphysicians may be capable of performing safe and effective screening for colorectal cancer with flexible sigmoidoscopy. An increased use of nonphysicians to perform sigmoidoscopy may increase the availability and reduce the cost of the procedure.

7125 How best to diagnose ipmt.

Excerpt The myelodysplastic syndromes are a heterogeneous group of bone marrow stem-cell disorders characterized by peripheral cytopenias and hypercellular dysplastic bone marrows (1, 2). The myelo...

Prevalence and predictors of multiple behavioral risk factors for colon cancer.

Purpose To describe the colorectal cancer‐screening program at Harvard Vanguard Medical Associates, a large multispecialty medical group, in which nurse practitioners (NPs) and physician assistants (PAs) perform screening flexible sigmoidoscopies. Data Sources Scientific literature, consensus statements and guidelines, and the protocol utilized to train NPs and PAs to perform flexible sigmoi‐doscopy. Data from 9,500 screening proce‐dures are presented. Conclusions In comparison with gastroenterologists, trained NP and PA endoscopists perform screening flexible sigmoidoscopy with similar accuracy and safety but at lower cost. Implications for Practice Screening flexible sigmoidoscopy performed by NPs and PAs may increase the availability and lower the cost of flexible sigmoidoscopy for colorectal cancer screening.

HERBAL TOXICITY AND FATAL HEPATIC FAILURE

The purpose of the study was to review a single institutional experience of intraductal papillary mucinous tumors (IPMT) and compare different diagnostic modalities. Background: IPMT or mucinous ductal ectasia is a rare neoplasm of the pancreas. It is characterized by extensive intraductal growth with slow invasion and metastasis having a much better prognosis. Diagnosis is usually made by ERCP showing dilated main and side branches with multiple filling defects that represent mucus and often mucus extruding from the papilla. The value of brush cytology and biopsy is unknown. Methods: The medical records, endoscopic findings, brushing results, surgical findings and surgical pathology of 22 patients over a 6 year period were reviewed. Results: The mean age at presentation was 63.1 years. There were 15 females and 7 males. The prevalence of abdominal pain was 86%, h/o pancreatitis 64%, wt loss 23%, diabetes 18%, cholangitis 9%, steatorrhea 5%. CT scan was done in 11 (50 %) and showed cystic dilation in 1, cystic mass in 5, solid mass in 3, and was negative in 2. Three (14%) were found to have pancreas divisum with mucus in the dilated dorsal duct. Nineteen (86%) had tumor involvement in the head of the pancreas and 3 (14%) in the tail. Brushing of the pancreatic duct was performed in 17, biopsy in 8 with only 2 positive for mucinous neoplasm in each (using strict criteria). Pancreatoscopy was performed in 2 patients and revealed the intraductal papillary growth and white gelatinous mucus in both patients. Endoscopic ultrasound was performed on one patient and showed hyperechogenic collection in the dilated pancreatic duct. Eight patients underwent surgery; 4 pancreaticoduodenectomy, 2 pylorus preserving pancreaticoduodenectomy, 1 distal pancreatectomy and 1 total pancreatectomy. Invasive carcinoma was present in 2 (25%). Conclusion: IPMT which has malignant potential, presents with nonspecific symptoms. Non-invasive imaging may be misleading. ERCP is the procedure of choice in making the diagnosis. Brushings or biopsies of the pancreatic duct are insensitive. Pancreatoscopy is useful in determining the extent of the lesion to help guide surgical resection.