Fecal occult blood testing when colonoscopy capacity is limited.
ABSTRACT Fecal occult blood testing (FOBT) can be adapted to a limited colonoscopy capacity by narrowing the age range or extending the screening interval, by using a more specific test or hemoglobin cutoff level for referral to colonoscopy, and by restricting surveillance colonoscopy. Which of these options is most clinically effective and cost-effective has yet to be established.
We used the validated MISCAN-Colon microsimulation model to estimate the number of colonoscopies, costs, and health effects of different screening strategies using guaiac FOBT or fecal immunochemical test (FIT) at various hemoglobin cutoff levels between 50 and 200 ng hemoglobin per mL, different surveillance strategies, and various age ranges. We optimized the allocation of a limited number of colonoscopies on the basis of incremental cost-effectiveness.
When colonoscopy capacity was unlimited, the optimal screening strategy was to administer an annual FIT with a 50 ng/mL hemoglobin cutoff level in individuals aged 45-80 years and to offer colonoscopy surveillance to all individuals with adenomas. When colonoscopy capacity was decreasing, the optimal screening adaptation was to first increase the FIT hemoglobin cutoff value to 200 ng hemoglobin per mL and narrow the age range to 50-75 years, to restrict colonoscopy surveillance, and finally to further decrease the number of screening rounds. FIT screening was always more cost-effective compared with guaiac FOBT. Doubling colonoscopy capacity increased the benefits of FIT screening up to 100%.
FIT should be used at higher hemoglobin cutoff levels when colonoscopy capacity is limited compared with unlimited and is more effective in terms of health outcomes and cost compared with guaiac FOBT at all colonoscopy capacity levels. Increasing the colonoscopy capacity substantially increases the health benefits of FIT screening.
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ABSTRACT: Objectives. We assessed the protocols and system processes for colorectal cancer (CRC) screening at federally qualified health centers (FQHCs) in 4 midwestern states. Methods. We identified 49 FQHCs in 4 states. In January 2013, we mailed their medical directors a 49-item questionnaire about policies on CRC screening, use of electronic medical records, types of CRC screening recommended, clinic tracking systems, referrals for colonoscopy, and barriers to providing CRC. Results. Forty-four questionnaires (90%) were returned. Thirty-three of the respondents (75%) estimated the proportion of their patients up-to-date with CRC screening, with a mean of 35%. One major barrier to screening was inability to provide colonoscopy for patients with a positive fecal occult blood test (59%). The correlation of system strategies and estimated percentage of patients up-to-date with CRC screening was 0.43 (P = .01). Conclusions. CRC system strategies were associated with higher CRC screening rates. Implementing system strategies for CRC screening takes time and effort and is important to maintain, to help prevent, or to cure many cases of CRC, the second leading cause of cancer in the United States. (Am J Public Health. Published online ahead of print May 15, 2014: e1-e8. doi:10.2105/AJPH.2013.301790).American Journal of Public Health 05/2014; · 3.93 Impact Factor
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ABSTRACT: Recent reports suggest that autoantibodies directed to aberrantly glycosylated mucins, in particular MUC1 and MUC4, are found in patients with colorectal cancer. There is, however, limited information on the autoantibody levels prior to clinical diagnosis, and their utility in cancer screening in the general population. In this study, we have generated O-glycosylated synthetic MUC1 and MUC4 peptides in vitro, to mimic cancer associated glycoforms, and displayed these on microarrays. The assay's performance was tested through an initial screening of serum samples taken from patients at the time of colorectal cancer diagnosis and healthy controls. Subsequently the selected biomarkers were evaluated in a blinded nested case control study, using stored serum samples from among the 50,640 women randomised to the multimodal arm of the UKCTOCS, where women gave annual blood samples for several years. Cases were 97 postmenopausal women who developed colorectal cancer following recruitment, and were age-matched to 97 women without any history of cancer. MUC1-STn and MUC1-Core3 IgG autoantibodies identified cases with 8.2% and 13.4% sensitivity, respectively, at 95% specificity. IgA to MUC4-glycoforms were unable to discriminate between cases and controls in the UKCTOCS sera. Additional analysis was undertaken by combining the data of MUC1-STn and MUC1-Core3 with previously generated data on autoantibodies to p53 peptides, which increased the sensitivity to 32.0% at 95% specificity in the UKCTOCS set. These findings suggest that a combination of antibody signatures may have a role as part of a biomarker panel for the early detection of colorectal cancer. © 2013 Wiley Periodicals, Inc.International Journal of Cancer 10/2013; · 6.20 Impact Factor
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ABSTRACT: To assess the fecal immunochemical test (FIT) accuracy for colorectal cancer (CRC) and advanced neoplasia (AN) detection in CRC screening. We performed a multicentric, prospective, double blind study of diagnostic tests on asymptomatic average-risk individuals submitted to screening colonoscopy. Two stool samples were collected and the fecal hemoglobin concentration was determined in the first sample (FIT1) and the highest level of both samples (FITmax) using the OC-sensor™. Areas under the curve (AUC) for CRC and AN were calculated. The best FIT1 and FITmax cut-off values for CRC were determined. At this threshold, number needed to scope (NNS) to detect a CRC and an AN and the cost per lesion detected were calculated. About 779 individuals were included. An AN was found in 97 (12.5%) individuals: a CRC in 5 (0.6%) and an advanced adenoma (≥ 10 mm, villous histology or high grade dysplasia) in 92 (11.9%) subjects. For CRC diagnosis, FIT1 AUC was 0.96 (95%CI: 0.95-0.98) and FITmax AUC was 0.95 (95%CI: 0.93-0.97). For AN, FIT1 and FITmax AUC were similar (0.72, 95%CI: 0.66-0.78 vs 0.73, 95%CI: 0.68-0.79, respectively, P = 0.34). Depending on the number of determinations and the positivity threshold cut-off used sensitivity for AN detection ranged between 28% and 42% and specificity between 91% and 97%. At the best cut-off point for CRC detection (115 ng/mL), the NNS to detect a CRC were 10.2 and 15.8; and the cost per CRC was 1814€ and 2985€ on FIT1 and FITmax strategies respectively. At this threshold the sensitivity, NNS and cost per AN detected were 30%, 1.76, and 306€, in FIT1 strategy, and 36%, 2.26€ and 426€, in FITmax strategy, respectively. Performing two tests does not improve diagnostic accuracy, but increases cost and NNS to detect a lesion.World Journal of Gastroenterology 01/2014; 20(4):1038-47. · 2.55 Impact Factor