Determination of qualitative telomerase activity as an adjunct to the diagnosis of pancreatic adenocarcinoma by EUS-guided fine-needle aspiration.

BACKGROUND: Telomerase activity is up-regulated in pancreatic cancer. Hence, measurement of telomerase activity in pancreatic needle-biopsy specimens could assist in establishing a positive diagnosis in specimens that are inadequate for cytology. OBJECTIVE: To determine the sensitivity and specificity of telomerase activity for neoplasia in a series of EUS-guided fine-needle aspirate (EUS-FNA) biopsies of pancreatic mass lesions. DESIGN: Prospective, consecutive, non-randomized cohort. SETTING: Academic hospital, tertiary referral center. PATIENTS: Seventy-one patients with a pancreatic mass diagnosed by cross-sectional imaging. INTERVENTIONS: EUS-FNA of 52 solid and 18 cystic pancreatic lesions. MAIN OUTCOME MEASUREMENTS: (1) Cytologic diagnosis; (2) tissue telomerase activity by semi-quantitative polymerase chain reaction; (3) patient demographics; (4) clinical outcomes. RESULTS: Cytology results were positive for adenocarcinoma in 40 patients with a solid pancreatic mass; of these, telomerase activity was detected in 31. There were no telomerase false-positive results. Telomerase results were positive in 6 of the 7 patients (86%) who had negative cytology results and who eventually were found to have biopsy-proven adenocarcinoma. The sensitivity and specificity of telomerase activity for detecting pancreatic adenocarcinoma in solid masses was 79% (95% CI, 64%-89%) and 100% (95% CI, 55%-100%). LIMITATIONS: Extremely high sensitivity and specificity of EUS-FNA cytology in solid lesions minimized the incremental benefit of telomerase. CONCLUSIONS: Telomerase activity can be measured readily in specimens obtained at EUS-FNA and accurately predicts malignancy. Used in combination with cytology, telomerase increased the sensitivity from 85% to 98% while maintaining the specificity at 100%. Lesions with negative cytology result and positive telomerase activity should be evaluated aggressively to exclude malignancy.

Sensitivity of upper endoscopy in diagnosing esophageal cancer.

Esophageal cancer is a common cause of dysphagia and upper endoscopy is the accepted standard for making the diagnosis; however, the accuracy of endoscopy is not known. The purpose of this study is to determine the sensitivity of upper endoscopy in making the diagnosis of esophageal cancer in clinical practice. All patients with a new diagnosis of esophageal cancer from 1997 to 2001 in the Tumor Registry of Wake Forest University Baptist Medical Center were identified. The medical records were reviewed to identify all patients who had undergone a previous endoscopy within two years that failed to diagnose esophageal cancer. The reason for failure was recorded. One hundred ten new cases of esophageal carcinoma were identified, and ten patients had had a previous false-negative endoscopy within two years for a sensitivity of 90.9% in clinical practice. The reasons for the failure of endoscopy were (1) lesion not seen in seven patients, (2) lesion seen and biopsied with benign histology in two patients, and (3) lesion seen but felt to be benign and not biopsied in one patient. Given the uncertain natural history of esophageal cancer, the data were also analyzed using a one-year window; this resulted in a sensitivity of 94.5%. The sensitivity of upper endoscopy in the diagnosis of esophageal cancer in general clinical practice is 90.9% using a two-year window and 94.5% using a one-year window. Understanding the reasons for the failure of endoscopy may allow us to improve the practice of endoscopy.

AGA future trends report: CT colonography.

BACKGROUND & AIMS: Computed tomographic colonography (CTC) was first described more than a decade ago. Recent advances in imaging hardware and software and results of clinical trials based on new methods for performing and interpreting images suggest that CTC may now be assessed as a method for colorectal cancer screening. METHODS: The Research Policy Committee of the American Gastroenterological Association assembled a task force to review the results of recent clinical trials and quantitative mathematical models pertaining to CTC. The goal of the task force was to assess the current knowledge about CTC and to evaluate the issues that will define its impact. RESULTS: Limitations in evaluating the current state of CTC technology include a wide variation in results of clinical trials. There are as yet insufficient data on the use of CTC in routine clinical practice. Limitations in the use of quantitative mathematical models make predictions based on such models of limited value. The cancer risk and therefore clinical importance of small colorectal polyps detected by CTC and/or nonpolypoid neoplasia not detected by CTC remains largely unknown. CONCLUSIONS: CTC is attractive as a colon imaging modality. It is therefore anticipated that CTC will have a significant impact on the practice of gastroenterology. However, the magnitude of the impact is currently unknown. Whether the ongoing implementation of CTC will increase or decrease the number of referrals for colonoscopy or shift the procedure from colorectal cancer screening to therapeutic interventions (e.g., polypectomy) is unknown at the present time. Multidisciplinary collaboration between gastroenterology and radiology to promote effective implementation and ongoing quality assurance will be important.

Infectious complications of pancreatitis: diagnosis and management.

Infected pancreatic necrosis is the leading cause of death in patients with severe acute pancreatitis. Early prophylactic antibiotic treatment is effective in preventing conversion of sterile necrosis to pancreatic infection, but its effect on mortality remains unproven. Fungal infections may predict a worse outcome, but no evidence supports the use of antifungal prophylaxis. Because infection of pancreatic necrosis by enteric bacteria can develop despite prophylaxis, a high index of suspicion should allow early detection followed by aggressive management.

Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia.

CONTEXT: Conventional colonoscopy is the best available method for detection of colorectal cancer; however, it is invasive and not without risk. Computed tomographic colonography (CTC), also known as virtual colonoscopy, has been reported to be reasonably accurate in the diagnosis of colorectal neoplasia in studies performed at expert centers. OBJECTIVE: To assess the accuracy of CTC in a large number of participants across multiple centers. DESIGN, SETTING, AND PARTICIPANTS: A nonrandomized, evaluator-blinded, noninferiority study design of 615 participants aged 50 years or older who were referred for routine, clinically indicated colonoscopy in 9 major hospital centers between April 17, 2000, and October 3, 2001. The CTC was performed by using multislice scanners immediately before standard colonoscopy; findings at colonoscopy were reported before and after segmental unblinding to the CTC results. MAIN OUTCOME MEASURES: The sensitivity and specificity of CTC and conventional colonoscopy in detecting participants with lesions sized at least 6 mm. Secondary outcomes included detection of all lesions, detection of advanced lesions, possible technical confounders, participant preferences, and evidence for increasing accuracy with experience. RESULTS: A total of 827 lesions were detected in 308 of 600 participants who underwent both procedures; 104 participants had lesions sized at least 6 mm. The sensitivity of CTC for detecting participants with 1 or more lesions sized at least 6 mm was 39.0% (95% confidence interval [CI], 29.6%-48.4%) and for lesions sized at least 10 mm, it was 55.0% (95% CI, 39.9%-70.0%). These results were significantly lower than those for conventional colonoscopy, with sensitivities of 99.0% (95% CI, 97.1%->99.9%) and 100%, respectively. A total of 496 participants were without any lesion sized at least 6 mm. The specificity of CTC and conventional colonoscopy for detecting participants without any lesion sized at least 6 mm was 90.5% (95% CI, 87.9%-93.1%) and 100%, respectively, and without lesions sized at least 10 mm, 96.0% (95% CI, 94.3%-97.6%) and 100%, respectively. Computed tomographic colonography missed 2 of 8 cancers. The accuracy of CTC varied considerably between centers and did not improve as the study progressed. Participants expressed no clear preference for either technique. CONCLUSIONS: Computed tomographic colonography by these methods is not yet ready for widespread clinical application. Techniques and training need to be improved.

Isolated proximal esophageal injury from blunt trauma: endoscopic stricture dilatation.

Blunt neck trauma can cause isolated esophageal injuries that may be difficult to recognize. A high index of suspicion is necessary for optimal identification and management of this condition. We report a case of blunt esophageal trauma resulting from a motor vehicle accident that was initially unrecognized until the patient developed a tight stricture of the cervical esophagus. This was successfully dilated endoscopically. Aerodigestive trauma resulting from neck injuries is reviewed with emphasis on the pathophysiology of esophageal trauma.

Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps.

BACKGROUND & AIMS: Virtual colonoscopy using abdominal spiral computed tomography scanning allows total colonic evaluation with minimal invasiveness. Two-dimensional images and selective 3-dimensional images of the colon are used to detect colorectal lesions. This trial used conventional colonoscopy with segmental unblinding to determine the ability of virtual colonoscopy to identify patients with colorectal lesions who need conventional colonoscopy. METHODS: We studied 205 patients with virtual colonoscopy using oral iodinated contrast preceding conventional colonoscopy. Colonic lavage was achieved with an oral sodium phosphosoda preparation and colonic distention with a carbon dioxide electronic insufflator. RESULTS: The overall sensitivity and specificity of virtual colonoscopy in identifying patients with colorectal lesions was 61.8% and 70.7%, respectively. Virtual colonoscopy was more accurate in identifying patients with lesions >/=6 mm (sensitivity 84.4% and specificity 83.1%) and those with lesions >/=10 mm (sensitivity 90% and specificity 94.6%). The negative predictive value of virtual colonoscopy was 95% for a 6-mm cutoff size and 98.9% for a 10-mm cutoff. Using a 10-mm cutoff, virtual colonoscopy precludes the need for conventional colonoscopy in 86% of patients with a 1% false-negative rate (68% with a 3.4% false-negative rate when using a 6-mm cutoff). CONCLUSIONS: Virtual colonoscopy has a high sensitivity and specificity for detecting patients with significant colorectal lesions. Its high negative predictive value may help reduce the number of negative screening colonoscopies. Further studies are needed to determine what lesion cutoff size is clinically acceptable and the appropriate interval time for repeat virtual colonoscopy when it detects lesions below this cutoff size.

Motion - computerized tomographic colography is a better method for screening for polyps: arguments for the motion.

Colorectal cancer is an important public health problem that is amenable to prevention and early treatment. Traditional screening techniques - fecal occult blood testing, flexible sigmoidoscopy, barium enema and colonoscopy - each have limitations in terms of diagnostic accuracy, cost and/or patient acceptability. Compliance with recommendations for screening has been poor, in part, because of negative perceptions about the available modalities. Virtual colonoscopy, or computerized tomographic colography, is a minimally invasive technique that safely evaluates the entire colon and does not require sedation. Thorough cleansing as well as immobilization and air insufflation of the colon is crucial to a successful examination. Sensitivity and specificity rates are reasonable, compared with conventional colonoscopy, and it has been shown that the latter technique can be averted in over two-thirds of cases, with few false-negative examinations. Most patients find virtual colonoscopy more acceptable than the conventional technique, and would prefer it if a repeat procedure were warranted. An economic analysis that found that computerized tomographic colography was less cost effective than conventional colonoscopy did not consider the indirect costs of the latter, which is an important limitation. Virtual colonoscopy is a novel radiological technique that may revolutionize screening for colorectal cancer.

The virtual colonoscopy study: a large multicenter clinical trial designed to compare two diagnostic screening procedures.

This paper reviews the design of a large multicenter clinical trial currently being conducted to test the equivalence of two screening procedures for colorectal polyps. The primary outcome is the sensitivity and specificity of the new and standard procedures for detecting subjects with and without polyps of a size > or =6 mm, respectively. An important secondary outcome is the accuracy of these procedures in detecting individual polyps. A total of 619 participants underwent virtual colonoscopy, the new procedure, followed by conventional colonoscopy, the standard procedure. Strategies for the design and implementation of the study are shared as well as the challenges encountered.