Cumulative evaluation of a quantitative immunochemical fecal occult blood test to determine its optimal clinical use.

BACKGROUND: Quantified, human hemoglobin (Hb)-specific, immunochemical fecal occult blood test (IFOBT) measurements are now used for colorectal cancer (CRC) screening. The objective was to evaluate sensitivity and specificity for CRC and advanced adenomatous polyps (APs) by the fecal Hb threshold used to determine a positive test and the number of IFOBTs prepared per test, so as to determine the least number of colonoscopies required to detect a neoplasm. METHODS: Cumulative data were analyzed from a prospective cross-sectional double-blind study of 1682 consecutive, ambulatory, nonbleeding colonoscopy patients who volunteered for IFOBTs, most of above average risk, from 3 ambulatory-endoscopy centers. Fecal Hb was measured in 3 samples and analyzed by an automated instrument, and the highest result >or=50 ng Hb/mL of buffer was related to findings. RESULTS: Colonoscopy identified CRC in 20 patients and advanced APs in 129. Sensitivity for either was best when any of 3 tests had >or=50 ng Hb/mL of buffer; sensitivity was 61.1% (95% confidence interval [CI], 53.2-68.9), and specificity was 87.8% (95% CI, 86.2-89.4). Positive tests identified 100% of CRCs and 55% of advanced APs every 3.1 colonoscopies. Sensitivity of a single test at the commonly used 100-ng Hb/mL threshold was lower at 31.5% (95% CI, 24.1-39.0) (P<.001), but specificity was higher at 96.4% (95% CI, 95.5-97.3) (P<.001). Positive tests identified 65% of CRCs and 26.4% of advanced APs every 2.2 colonoscopies. CONCLUSIONS: The fecal Hb cutoff chosen by the screener and the number of samples collected per patient determine sensitivity and specificity for CRC/advanced AP; these factors determine the number of colonoscopies needed for positive tests and neoplasia yield. This information provides guidelines for IFOBT screening. Limitations are 1-time screening and most examinees not being at average risk for CRC.

The prevalence of ulcerative colitis in Israel: a twenty-year survey.

OBJECTIVES: This is the third survey we perform in the kibbutz population of Israel. The previous 2 surveys were 10 years apart, in 1987 and 1997, demonstrating an increase in ulcerative colitis (UC) prevalence. The aim of the present study was to confirm the trend for increasing UC prevalence in Israel. METHODS: There are 269 kibbutz settlements in Israel, with a total of 117,700 people, accounting for 2.4% of the Jewish Israeli population. The local physician for each kibbutz was contacted by mail, e-mail, telephone, and fax to obtain information on UC patients. Data were retrieved and updated to December 31, 2007, the point prevalence date. Details of sex, age, origin, clinical spectrum of the disease, therapy, and complications were recorded. RESULTS: There are 255 confirmed cases of UC, 138 women and 117 men (female: male ratio, 1.2:1). The prevalence rate rose from 121.08/100,000 in 1987 to 167.20/100,000 in 1997 and then to 216.65/100,000 in 2007 (P<0.0001). The rise in the second period was less than in the first period: 29% and 38%, respectively. The prevalence rate was higher in women than men, and in European/American-born>Asian/African-born>Israeli-born individuals. CONCLUSIONS: We observed an increase in the prevalence and mean annual incidence of UC in Israel, in men and women, with a decreasing gap between different ethnic groups. We believe that strong environmental influence is responsible for our observation.

Sensitivity, but not specificity, of a quantitative immunochemical fecal occult blood test for neoplasia is slightly increased by the use of low-dose aspirin, NSAIDs, and anticoagulants.

OBJECTIVES: We evaluated the effect of the use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDS), and anticoagulants on the performance of immunochemical fecal occult blood test (I-FOBT). METHODS: A prospective, cross-sectional study of 1,221 ambulatory patients having total colonoscopy after preparing three I-FOBTs. Information regarding the use of medications was collected from the health medical organization (HMO) database. I-FOBT was analyzed with the OC-MICRO instrument using both >or=75 and 100 ngHb/ml of buffer thresholds to determine positivity. RESULTS: Colorectal cancer (CRC) was found in 17 and advanced adenomatous polyp (AAP) in 97 patients. A total of 212 patients were using aspirin/NSAIDS at the time of I-FOBT testing. Qualitative analysis for the detection of AAP/CRC reveals a trend for an increased sensitivity with aspirin/NSAIDS use. At the threshold 75 ng/ml for positivity, the sensitivity for the detection of AAP/CRC was 66.7% for aspirin/NSAIDS use vs. 51.2% for nondrug takers (P=0.20), and at the threshold of 100 ng/ml, the sensitivity was 66.7 vs. 46.5% (P=0.09). The specificity, however, was not affected by the use of aspirin/NSAIDS. At the threshold of 75 ng/ml for positivity, the specificity for the detection of AAP/CRC was 89.5% for aspirin/NSAIDS use vs. 91.2% for nondrug takers (P=0.47), and at the threshold of 100 ng/ml, the specificity was 92.17 vs. 93.0% (P=0.69). A total of 33 patients were using antithrombotics/coagulants at the time of I-FOBT testing. This group was small; however, it appears that their use was also associated with a trend for increased sensitivity and no change in specificity. CONCLUSIONS: The use of aspirin/NSAIDS and anticoagulants was associated with a trend for increased sensitivity with no change in specificity for the detection of AAP/CRC. This study suggests that there is no need to stop these agents before I-FOBT testing.

The prevalence of Crohn's disease in Israel: a 20-year survey.

OBJECTIVES: This is the third survey that we have performed in the kibbutz population in Israel. The previous two surveys were 10 years apart, in 1987 and 1997, demonstrating an increase in Crohn's disease prevalence. The aim of the present study was to confirm the trend for increasing Crohn's disease prevalence in Israel. METHODS: There are 269 kibbutz settlements in Israel, with a total of 117,700 people, accounting for 2.4% of the Jewish Israeli population. The local physician for each kibbutz was contacted by mail, e-mail, telephone, and fax in order to obtain information on Crohn's disease patients. Data was retrieved and updated to 31st December 2007, the point prevalence date. Details of gender, age, origin, clinical spectrum of the disease, therapy, and complications were recorded. RESULTS: There were 133 confirmed cases of Crohn's disease. The prevalence rate rose from 25.53/100,000 in 1987 to 65.11/100,000 in 1997, and then to 112.99 in 2007 (P < 0.0001). The prevalence rate was higher in women than men, and Israeli- or European/American-born than Asian/African-born individuals. The rise in prevalence was steady from 1987 to 1997 and then to 2007 in all subgroups, except for Asian/African-born kibbutz members. In the last group, a decrease in prevalence was demonstrated between 1987 and 1997, and then a sharp increase between 1997 and 2007. CONCLUSIONS: We conclude that the incidence and prevalence of Crohn's disease increased in the three ethnic groups of Israeli Jews. Differences still exist but become smaller, maybe due to the strong environmental influence that overcame genetic preponderance.

A familial gastrointestinal cancer clinic: organization, aims and activities, 2004-2007.

BACKGROUND: Dedicated, organ-specific screening clinics have been shown to significantly reduce cancer morbidity and mortality. OBJECTIVES: To establish a dedicated clinic for Clalit Health Service patients at high risk for hereditary gastrointestinal cancer and to provide them with clinical and genetic counseling, diagnostic screening and follow-up. RESULTS: During the 3 years of the clinic's activity, 634 high risk families, including 3804 at-risk relatives, were evaluated. The most common conditions were hereditary colorectal syndromes, Lynch syndrome (n=259), undefined young-onset or familial colorectal cancer (n=214), familial adenomatous polyposis (n=55), and others (n=106). They entered follow-up protocols and 52 underwent surgical procedures. CONCLUSIONS: Consistent public and professional education is needed to increase awareness of hereditary colorectal cancer and the possibility of family screening, early diagnosis and therapy. The public health services--i.e., the four health management organizations--should provide genetic testing for these patients who, at present, are required to pay for almost all of these available but costly tests. Dedicated colorectal surgical units are needed to provide the specialized therapeutic procedures needed by patients with familial colorectal cancer. Our future plans include adding psychosocial support for these at-risk patients and their families as well as preventive lifestyle and dietary intervention.

Screening colonoscopy for colorectal cancer in asymptomatic people: a meta-analysis.

OBJECTIVE: The preferred method for screening asymptomatic people for colorectal cancer (CRC) is colonoscopy, according to the new American guidelines. The aim of our study was to perform a meta-analysis of the prospective cohorts using total colonoscopy for screening this population for CRC. We looked for the diagnostic yield of the procedure as well as for its safety in a screening setting. METHODS: We included papers with more than 500 participants and only those reporting diagnostic yield of adenoma (and/or advanced adenoma) and CRC. Nested analysis were performed for secondary endpoints of complications and CRC stages when this information was available. All analyses were performed with StatDirect Statistical software, version 2.6.1 ( http://www.statsdirect.com ). RESULTS: Our search yielded ten studies of screening colonoscopy conducted in asymptomatic people that met our inclusion criteria, with a total of 68,324 participants. Colonoscopy was complete and reached the cecum in 97% of the procedures. Colorectal cancer was found in 0.78% of the participants (95% confidence interval 0.13-2.97%). Stage I or II were found in 77% of the patients with CRC. Advanced adenoma was found in 5% of the cases (95% confidence interval 4-6%). Complications were rare and described in five cohorts. Perforation developed in 0.01% of the cases (95% confidence interval 0.006-0.02%) and bleeding in 0.05% (95% confidence interval 0.02-0.09%). CONCLUSIONS: Our findings support the notion that colonoscopy is feasible and a suitable method for screening for CRC in asymptomatic people.

Helicobacter pylori recurrence in developed and developing countries: meta-analysis of 13C-urea breath test follow-up after eradication.

OBJECTIVE: Recurrence of Helicobacter pylori infection after eradication is rare in developed countries and more frequent in developing countries. Most recurrent cases are attributed to recrudescence (recolonization of the same strain within 12 months) rather than to reinfection (colonization with a new strain after more than 12 months). The aim of the study was to analyze recurrence rates in developed and developing countries and to deduce the relative roles of recrudescence and reinfection. METHODS: The PubMed database was searched up to January 31, 2007 using the keywords "Helicobacter pylori" or "H. pylori" and "recurrence" or "recrudescence," or "reinfection." Only prospective case studies in adults that used the (13)C-urea breath test ((13)CUBT) were included. Meta-analyses were performed with statdirect Statistical software, version 2.6.1, StatsDirect Ltd, Chesire, UK. RESULTS: The literature search yielded 10 studies of H. pylori recurrence in developed countries (3014 patients followed for 24-60 months) and 7 studies in developing countries (2071 patients followed for 12-60 months). The calculated annual recurrence rates were 2.67% and 13.00%, respectively. Nested meta-analysis of cases with a longer follow-up after eradication revealed an annual recurrence rate of 1.45% (RR 0.54) in developed countries and 12.00% (RR 0.92) in developing countries. CONCLUSIONS: The similarity of the annual recurrence rates during the first year after eradication and the annual recurrence rates in the second year after successful eradication in developing countries supports reinfection as the main cause in the second period. Therefore, a different approach for follow-up of H. pylori eradication may be needed between developed and developing countries.

Helicobacter pylori recurrence and infection rate in Israeli adults.

INTRODUCTION: In developing countries the recurrence rate of Helicobacter pylori after successful eradication therapy is as high as 42%, while in developed countries it is estimated to be less than 3%. Such figures are very important in terms of determining clinical strategy and outcome. AIM: To estimate the recurrence rate of H. pylori in Israel using the database of the "Central H. Pylori Laboratory of Clalit Health Services". METHODS: The database was searched for patients who had undergone the [(13)C]-urea breath test ([(13)C]-UBT) for validation of the successful eradication of H. pylori or for evaluation of dyspepsia 7 years previously and for whom the result had been negative. These patients were invited to participate in the trial, fill a symptom questionnaire and undergo another [(13)C]-UBT. RESULTS: A In total, 65 patients participated; of these, 26 patients had tested negative in the first( 13)CUBT, indicating the successful eradication of H. pylori (Group A), and 39 had been tested for dyspepsia (Group B). One patient in each group had a positive [(13)C]-UBT - 3.84% in Group A and 2.56% in Group B (non-significant difference, NS). The mean annual H. pylori recurrence rate was calculated to be 0.55% and 0.37% in Group A and Group B patients, respectively (NS). CONCLUSION: Our results shown a very low re-infection or new infection rates in Israeli adults and are in line with other trials in developed countries; they do not support the a retesting program for patients after a successful eradication therapy.

A quantitative immunochemical fecal occult blood test for colorectal neoplasia.

BACKGROUND: Guaiac-based fecal occult blood tests (FOBTs) for colorectal cancer screening are not specific for human hemoglobin and have low sensitivity. Automated-development, immunochemical FOBT is quality-controlled, is specific for human hemoglobin, and does not require diet restriction. OBJECTIVES: To measure the sensitivity and specificity of quantitative immunochemical fecal hemoglobin measurements for detection of cancer and advanced adenoma in patients undergoing colonoscopy, to determine fecal hemoglobin thresholds that give the highest posttest probability for neoplasia, and to determine the number of immunochemical FOBTs needed. DESIGN: Prospective, cross-sectional study. SETTING: Ambulatory endoscopy services of the main health medical organization in Tel Aviv, Israel. PARTICIPANTS: 1000 consecutive ambulatory patients--some asymptomatic but at increased risk for colorectal neoplasia and some symptomatic--who were undergoing elective colonoscopy and volunteered to prepare immunochemical FOBTs. INTERVENTION: The hemoglobin content of 3 bowel movements was measured, and the highest value was compared with colonoscopy findings. MEASUREMENTS: Sensitivity, specificity, predictive values, likelihood ratios, and 95% CIs of fecal hemoglobin measurements for clinically significant neoplasia, their relationship to the amount of fecal hemoglobin measured, and the number of immunochemical FOBTs performed. RESULTS: Colonoscopy identified clinically significant neoplasia in 91 patients (cancer in 17 patients and advanced adenomas in 74 patients). Using 3 immunochemical FOBTs and a hemoglobin threshold of 75 ng/mL of buffer, sensitivity and specificity were 94.1% (95% CI, 82.9% to 100.0%) and 87.5% (CI, 85.4% to 89.6%), respectively, for cancer and 67% (CI, 57.4% to 76.7%) and 91.4% (CI, 89.6% to 93.2%), respectively, for any clinically significant neoplasia. LIMITATIONS: The fecal sampling method is standardized, but the sample size depends on fecal consistency. Some patients were tested while discontinuing aspirin and anticoagulant therapies. Study patients were at increased risk, and results might not apply to average-risk populations. CONCLUSIONS: Quantitative immunochemical FOBT has good sensitivity and specificity for detection of clinically significant neoplasia. Test performance in screening average-risk populations is not known.

Colonosopy screening and surveillance of colorectal cancer and polyps: physicians' knowledge.

BACKGROUND: Colonoscopy is the gold standard procedure for screening for colorectal cancer and surveillance after polypectomy or colorectal cancer surgery, for diagnosis in symptomatic patients and patients with fecal occult blood, and for screening in the high risk population. The adherence of referring physicians to the accepted recommendations can prevent long waiting lists for colonoscopy and save lives, costs and resources. OBJECTIVES: To evaluate the knowledge of primary care physicians and gastroenterologists in Israel about current guidelines for colonoscopy screening and surveillance. METHODS: A 10-item questionnaire on proper follow-up colonoscopy for surveillance after polypectomy and screening for colorectal cancer in various clinical and epidemiological situations was administered to 100 expert gastroenterologists and 100 primary care physicians at a professional meeting. Answers were evaluated for each group of physicians and compared using the chi-square test. RESULTS: The compliance rate was 45% for the gastroenterologists and 80% for the primary care physicians. The rate of correct answers to the specific items ranged from 18.7% to 93.75% for the gastroenterologists and from 6.2% to 58.5% for the primary care physicians (P< 0.001 for almost every item). CONCLUSIONS: The knowledge of physicians regarding the screening and surveillance of colorectal cancer needs to be improved.