Inappropriate use of the faecal occult blood test in a university hospital in the Netherlands.

OBJECTIVES: Although all international guidelines state that there is no indication to perform a faecal occult blood test (FOBT) in symptomatic patients, we believe the test is frequently used as a diagnostic test. The objective of this study was to investigate whether the current guidelines for FOBT use are being followed in the Netherlands. METHODS: The frequency of reasons for ordering a FOBT in 15 hospitals over a time period of 1 year was determined and the consequences of the test result on the diagnostic workup were determined by a retrospective search of electronic hospital charts. RESULTS: In 14 of the 15 hospitals a FOBT was available and totally 2993 FOBTs were performed in 1 year. A total of 201 electronic charts were retrieved. The FOBTs were ordered because of anaemia (41%), suspicion of rectal bleeding (17%), abdominal pain (14%), changed bowel habits (10%) or others (18%). A positive test result was found in 66 (33%) patients and a negative in 133 (66%). Respectively, 38% (25/66) of the patients with a positive and 41% (55/133) of the patients with a negative test result received a gastrointestinal follow-up investigation. In 25/80 investigations, a possible cause of rectal blood loss was detected, of which 13 had a positive FOBT result. CONCLUSION: This study demonstrates that current guidelines on FOBT use are not followed in the Netherlands and that a FOBT is often used as a diagnostic tool instead of a screening tool, thereby causing confusion and unnecessary delays in the diagnostic workup of patients.

Similar fecal immunochemical test results in screening and referral colorectal cancer.

AIM: To improve the interpretation of fecal immunochemical test (FIT) results in colorectal cancer (CRC) cases from screening and referral cohorts. METHODS: In this comparative observational study, two prospective cohorts of CRC cases were compared. The first cohort was obtained from 10 322 average risk subjects invited for CRC screening with FIT, of which, only subjects with a positive FIT were referred for colonoscopy. The second cohort was obtained from 3637 subjects scheduled for elective colonoscopy with a positive FIT result. The same FIT and positivity threshold (OC sensor; ≥ 50 ng/mL) was used in both cohorts. Colonoscopy was performed in all referral subjects and in FIT positive screening subjects. All CRC cases were selected from both cohorts. Outcome measurements were mean FIT results and FIT scores per tissue tumor stage (T stage). RESULTS: One hundred and eighteen patients with CRC were included in the present study: 28 cases obtained from the screening cohort (64% male; mean age 65 years, SD 6.5) and 90 cases obtained from the referral cohort (58% male; mean age 69 years, SD 9.8). The mean FIT results found were higher in the referral cohort (829 ± 302 ng/mL vs 613 ± 368 ng/mL, P = 0.02). Tissue tumor stage (T stage) distribution was different between both populations [screening population: 13 (46%) T1, eight (29%) T2, six (21%) T3, one (4%) T4 carcinoma; referral population: 12 (13%) T1, 22 (24%) T2, 52 (58%) T3, four (4%) T4 carcinoma], and higher T stage was significantly associated with higher FIT results (P < 0.001). Per tumor stage, no significant difference in mean FIT results was observed (screening vs referral: T1 498 ± 382 ng/mL vs 725 ± 374 ng/mL, P = 0.22; T2 787 ± 303 ng/mL vs 794 ± 341 ng/mL, P = 0.79; T3 563 ± 368 ng/mL vs 870 ± 258 ng/mL, P = 0.13; T4 not available). After correction for T stage in logistic regression analysis, no significant differences in mean FIT results were observed between both types of cohorts (P = 0.10). CONCLUSION: Differences in T stage distribution largely explain differences in FIT results between screening and referral cohorts. Therefore, FIT results should be reported according to T stage.

Colorectal cancer screening comparing no screening, immunochemical and guaiac fecal occult blood tests: a cost-effectiveness analysis.

Comparability of cost-effectiveness of colorectal cancer (CRC) screening strategies is limited if heterogeneous study data are combined. We analyzed prospective empirical data from a randomized-controlled trial to compare cost-effectiveness of screening with either one round of immunochemical fecal occult blood testing (I-FOBT; OC-Sensor®), one round of guaiac FOBT (G-FOBT; Hemoccult-II®) or no screening in Dutch aged 50 to 75 years, completed with cancer registry and literature data, from a third-party payer perspective in a Markov model with first- and second-order Monte Carlo simulation. Costs were measured in Euros (€), effects in life-years gained, and both were discounted with 3%. Uncertainty surrounding important parameters was analyzed. I-FOBT dominated the alternatives: after one round of I-FOBT screening, a hypothetical person would on average gain 0.003 life-years and save the health care system €27 compared with G-FOBT and 0.003 life years and €72 compared with no screening. Overall, in 4,460,265 Dutch aged 50-75 years, after one round I-FOBT screening, 13,400 life-years and €320 million would have been saved compared with no screening. I-FOBT also dominated in sensitivity analyses, varying uncertainty surrounding important effect and cost parameters. CRC screening with I-FOBT dominated G-FOBT and no screening with or without accounting for uncertainty.

Comparison of guaiac and immunological fecal occult blood tests in colorectal cancer screening: the patient perspective.

OBJECTIVE: Colorectal cancer (CRC) screening programs can decide upon the type of fecal occult blood test (FOBT): the guaiac FOBT (g-FOBT) or the immunological FOBT (i-FOBT). The effectiveness of any screening program depends not only on the diagnostic performance of the screening test but also on the compliance and general acceptance of the test by the public. Any decision on the type of FOBT for CRC screening should also take acceptation and perception into account. The aim of the present study was to study differences in patient perception between i-FOBT and g-FOBT and differences in perception and participation rates among relevant subgroups in a population based study. MATERIAL AND METHODS: Differences in patient perception of i-FOBT and g-FOBT and differences in perception and participation rates among relevant subgroups were investigated (n = 20,623) by sending a short questionnaire to all invited to the first Dutch CRC screening trial. RESULTS: i-FOBT was perceived significantly more favorable than g-FOBT. About 1275 (32%) participants reported the g-FOBT not easy to use, not easy to perform, disgusting or shameful compared to 742 (16%) for the i-FOBT (p < 0.001). The participation rate was significantly higher in those who received i-FOBT compared to the g-FOBT group: 6159 of 10,322 (60%) versus 4839 of 10,301 (47%) (p < 0.001). CONCLUSIONS: These findings support the selection of i-FOBT as the more appropriate test for population screening programs.

CT colonography with limited bowel preparation for the detection of colorectal neoplasia in an FOBT positive screening population.

PURPOSE: Aim was to evaluate the accuracy of computed tomography colonography (CTC) for detection of colorectal neoplasia in a Fecal Occult Blood Test (FOBT) positive screening population. METHODS: In three different institutions, consecutive FOBT positives underwent CTC after laxative free iodine tagging bowel preparation followed by colonoscopy with segmental unblinding. Each CTC was read by two experienced observers. For CTC and for colonoscopy the per-polyp sensitivity and per-patient sensitivity and specificity were calculated for detection of carcinomas, advanced adenomas, and adenomas. RESULTS: In total 22 of 302 included FOBT positive participants had a carcinoma (7%) and 137 had an adenoma or carcinoma ≥10 mm (45%). CTC sensitivity for carcinoma was 95% with one rectal carcinoma as false negative finding. CTC sensitivity for advanced adenomas was 92% (95% CI: 88-96) vs. 96% (95% CI: 93-99) for colonoscopy (P = 0.26). For adenomas and carcinomas ≥10 mm the CTC per-polyp sensitivity was 93% (95% CI: 89-97) vs. 97% (95% CI: 94-99) for colonoscopy (P = 0.17). The per-patient sensitivity for the detection of adenomas and carcinomas ≥10 mm was 95% (95% CI: 91-99) for CTC vs. 99% (95% CI: 98-100) for colonoscopy (P = 0.07), while the per-patient specificity was 90% (95% CI: 86-95) and 96% (95% CI: 94-99), respectively (P < 0.001). CONCLUSION: CTC with limited bowel preparation performed in an FOBT positive screening population has high diagnostic accuracy for the detection of adenomas and carcinomas and a sensitivity similar to that of colonoscopy for relevant lesions.

False negative fecal occult blood tests due to delayed sample return in colorectal cancer screening.

Delayed return of immunochemical fecal occult blood test (iFOBT) samples to a laboratory might cause false negatives because of hemoglobin degradation. Quantitative iFOBT's became increasingly more accepted in colorectal cancer screening. Therefore, we studied the effects of delay between sampling and laboratory delivery on iFOBT performance. IFOBT positivity (>or=50 ng/ml hemoglobin) in colorectal cancer screening participants without delay between sampling and laboratory delivery (<5 days), was compared with positivity in participants with >or=5 and >or=7 days delay. Additionally, positive tests were stored at room temperature and retested 5 times within 10-14 days. The sampling date was reported by 61% (n = 3,767) of the participants: in 19% delay was >or=5 days and in 5% >or=7 days. Compared with no-delay, the adenoma detection rate was already significantly decreased after >or=5 days delay (OR 0.6; 95%CI 0.4-0.9). We retested iFOBT samples of 170 positives of which 139 (82%) had a colonoscopy: 45 (32%) had advanced adenomas (not colorectal cancer) and 8 (6%) had colorectal cancer. Mean daily fecal hemoglobin decrease was 29 ng/ml (S.D. 38 and median 11 ng/ml). In patients with advanced adenomas, hemoglobin in the sample was <50 ng/ml in 5 (11%) 2-3 days after the initial test and in 16 (36%) after 10-14 days. Seven days after the initial test, 2 (25%) colorectal cancer patients became false negative. Both had stage I colorectal cancer and initial values below 100 ng/ml, where the average for stage I is 532 ng/ml. Delay in sample return increased false negative immunochemical FOBT's. Mainly precursor lesions, but also colorectal cancer, will be missed due to delayed sample return.

Adherence to surveillance guidelines for dysplasia and colorectal carcinoma in ulcerative and Crohn's colitis patients in the Netherlands.

AIM: To study adherence to the widely accepted surveillance guidelines for patients with long-standing colitis in The Netherlands. METHODS: A questionnaire was sent to all 244 gastroenterologists in The Netherlands. RESULTS: The response rate was 63%. Of all gastroenterologists, 95% performed endoscopic surveillance in ulcerative colitis (UC) patients and 65% in patients with Crohn's colitis. The American Gastroenterological Association (AGA) guidelines were followed by 27%, while 27% and 46% followed their local hospital protocol or no specific protocol, respectively. The surveillance was correctly initiated in cases of pancolitis by 53%, and in cases of left-sided colitis by 44% of the gastroenterologists. Although guidelines recommend 4 biopsies every 10 cm, less than 30 biopsies per colonoscopy were taken by 73% of the responders. Only 31%, 68% and 58% of the gastroenterologists referred patients for colectomy when low-grade dysplasia, high-grade dysplasia (HGD) or Dysplasia Associated Lesion or Mass (DALM) was present, respectively. CONCLUSION: Most Dutch gastroenterologists perform endoscopic surveillance without following international recommended guidelines. This practice potentially leads to a decreased sensitivity for dysplasia, rendering screening for colorectal cancer in this population highly ineffective.

Random comparison of guaiac and immunochemical fecal occult blood tests for colorectal cancer in a screening population.

BACKGROUND & AIMS: Despite poor performance, guaiac-based fecal occult blood tests (G-FOBT) are most frequently implemented for colorectal cancer screening. Immunochemical fecal occult blood tests (I-FOBT) are claimed to perform better, without randomized comparison in screening populations. Our aim was to randomly compare G-FOBT with I-FOBT in a screening population. METHODS: We conducted a population-based study on a random sample of 20,623 individuals 50-75 years of age, randomized to either G-FOBT (Hemoccult-II) or I-FOBT (OC-Sensor). Tests and invitations were sent together. For I-FOBT, the standard cutoff of 100 ng/ml was used. Positive FOBTs were verified with colonoscopy. Advanced adenomas were defined as >or=10 mm, high-grade dysplasia, or >or=20% villous component. RESULTS: There were 10,993 tests returned: 4836 (46.9%) G-FOBTs and 6157 (59.6%) I-FOBTs. The participation rate difference was 12.7% (P < .01). Of G-FOBTs, 117 (2.4%) were positive versus 339 (5.5%) of I-FOBTs. The positivity rate difference was 3.1% (P < .01). Cancer and advanced adenomas were found, respectively, in 11 and 48 of G-FOBTs and in 24 and 121 of I-FOBTs. Differences in positive predictive value for cancer and advanced adenomas and cancer were, respectively, 2.1% (P = .4) and -3.6% (P = .5). Differences in specificities favor G-FOBT and were, respectively, 2.3% (P < .01) and -1.3% (P < .01). Differences in intention-to-screen detection rates favor I-FOBT and were, respectively, 0.1% (P < .05) and 0.9% (P < .01). CONCLUSIONS: The number-to-scope to find 1 cancer was comparable between the tests. However, participation and detection rates for advanced adenomas and cancer were significantly higher for I-FOBT. G-FOBT significantly underestimates the prevalence of advanced adenomas and cancer in the screening population compared with I-FOBT.