Positive Predictive Value For Advanced Neoplasia Research Articles

Positive Predictive Value for Multitarget Stool DNA After Bariatric and Metabolic Surgery.

Bariatric and metabolic surgery (BMS) may adversely affect noninvasive stool tests for colorectal cancer (CRC) screening through several mechanisms. Multitarget stool DNA (mt-sDNA) is approved for CRC screening; however, performance in post-BMS patients is unknown. As the rates of BMS are anticipated to increase with rising incidence of obesity, it is important to evaluate mt-sDNA test performance among these patients. In a multisite academic and community-based practice, we obtained mt-sDNA results from 10/2014 to 12/2019 through electronic records and an institutional BMS registry. Average CRC risk patients with BMS prior to a positive mt-sDNA underwent a detailed chart review. Follow-up colonoscopy findings were compared to those among BMS patients screened with colonoscopy alone and a historical cohort of patients without BMS, screened by mt-sDNA. The primary study endpoint was the positive predictive value (PPV) for advanced colorectal neoplasia. Among 336 average-risk patients who had mt-sDNA after BMS, mt-sDNA was positive in 49 (14.6%), 47/49 (96%) underwent follow-up colonoscopy, and the PPV for advanced neoplasia was 12/47 (25.5%). This is similar to the PPV for advanced colorectal neoplasia (425/1542, 28%) in a historical cohort of persons without prior BMS, screened by mt-sDNA at our center (P = .86). Among those who had prior BMS, the rate of advanced neoplasia was higher after mt-sDNA compared to screening colonoscopy alone. Despite anatomic and physiologic mechanisms that could alter blood or DNA content in stool, BMS does not appear to adversely affect the PPV of mt-sDNA.

Abstract PO-247: Is colorectal cancer screening in West Africa worthwhile? A prospective multi-institutional study of 2,330 average-risk Nigerians using fecal immunochemical testing (FIT)

Abstract Objective: The estimated incidence of CRC is rising in many African countries. In Nigeria, it is the fourth most common cause of cancer death. More than half of CRC patients in Nigeria present with metastatic disease. Early detection and screening for CRC is a goal of the Nigerian National Cancer Control Plan. This study assessed the performance of the fecal immunochemical test (FIT) as a CRC screening modality in an average-risk population in Nigeria. Methods: A population-based, cross-sectional study of FIT-based CRC screening was undertaken. Asymptomatic average-risk participants aged 45-75 years in three states in Southwest Nigeria were screened using a qualitative (50ng/mL) FIT test. Participants were invited to enroll using age- and sex-stratified convenience sampling following community outreach. Participants with positive test results underwent colonoscopy and the positive predictive value (PPV) of FIT-based CRC screening for CRC and advanced adenomas (tubulovillous, villous or high grade dysplasia) was calculated. Information on demographics, cancer knowledge, and acceptability of the FIT test and colonoscopy were also collected. Results: Between January-April 2021, 2330 participants in 3 states (Osun, Kwara, Lagos) were enrolled in the study. The median age was 57 years. 68% had at least secondary level education. Participants were evenly spread across wealth quintiles. Baseline knowledge of CRC symptoms among participants was low, especially outside of Lagos. The test return rate was 90.6%, and FIT positivity rate was 20.5% overall (n=432); 11.2% in Lagos, 20.4% in Osun, and 27.8% in Kwara states. Among the FIT positive patients who completed colonoscopy (n=285; 66.0%), the positive predictive value (PPV) for invasive adenocarcinoma was 1.1%, and for advanced adenoma was 1.8%.[KTP1] [AD2] The acceptability of fecal-based CRC screening among participants was very high. Conclusions: CRC screening with qualitative FIT testing in Southwest Nigeria is feasible and acceptable to average-risk asymptomatic participants. The high false-positive rates and low PPV for advanced neoplasia, however, suggest it is not an optimal screening tool in this environment, particularly given the health resources required for endoscopic evaluation. Citation Format: Olusegun I. Alatise, Anna J. Dare, Patrick A. Akinyemi, Fatima B. Abdulkareem, Samuel A. Olatoke, Gregg C. Knapp, Peter T. Kingham. Is colorectal cancer screening in West Africa worthwhile? A prospective multi-institutional study of 2,330 average-risk Nigerians using fecal immunochemical testing (FIT) [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-247.

Positive predictive values of fecal immunochemical tests used in the STOP CRC pragmatic trial.

Annual fecal immunochemical testing (FIT) is cost‐effective for colorectal cancer (CRC) screening. However, FIT positivity rates and positive predictive value (PPV) can vary substantially, with false‐positive (FP) results adding to colonoscopy burden without improving cancer detection. Our objective was to describe FIT PPV and the factors associated with FP results among patients undergoing CRC screening. In an ongoing pragmatic clinical trial of mailed‐FIT outreach, clinics delivered one of three FIT brands (InSure, OC‐Micro, and Hemosure). Patients who had a positive FIT result and a follow‐up colonoscopy were included in this analysis (N = 1130). Patients’ demographic and medical histories were abstracted from electronic health records (EHR). Associations with a FP result (ie, a positive FIT result with no evidence of advanced neoplasia during follow‐up colonoscopy) were evaluated for FIT brand and patient factors using mixed‐effects multivariable logistic regression. The mean proportion of FIT‐positive results ranged from 8% in centers using the OC‐Micro test to 21% for Hemosure. PPVs for advanced neoplasia were 0.30 to 0.17, respectively (P for χ 2 = 0.08). In multivariable‐adjusted models, use of Hemosure was associated with greater odds of a FP result than OC‐Micro (OR = 2.00, 95% CI: 0.47‐8.56) or InSure (OR = 1.72, 95% CI: 0.44‐6.68). However, only female sex (OR = 1.58, 95% CI: 1.19‐2.10) and history of a colorectal condition (OR = 2.17, 95% CI: 1.13‐4.15) were significantly associated with FP. In conclusion, FIT positivity varied by brand, and FP results differed by patient factors available through the EHR. These results can be used to minimize the frequency of FP results, reducing patient distress and colonoscopy burden.

Effect of anticoagulants and NSAIDs on accuracy of faecal immunochemical tests (FITs) in colorectal cancer screening: a systematic review and meta-analysis.

Most colorectal cancer (CRC) screening programmes are nowadays based on faecal immunochemical testing (FIT). Eligible subjects often use oral anticoagulants (OACs) or non-steroidal anti-inflammatory drugs (NSAIDs), which could possibly stimulate bleeding from both benign and premalignant lesions in the colon. The aim of this meta-analysis was to study the effect of OACs and NSAIDs use on FIT performance. A systematic search was conducted until June 2017 to retrieve studies from PubMed, Embase, MEDLINE, Web of science, Cochrane Central and Google Scholar. Studies were included when reporting on FIT results in users versus non-users of OACs and/or NSAIDs in average risk CRC screening populations. Primary outcome was positive predictive value for advanced neoplasia (PPVAN) of FIT in relation to OACs/NSAIDs use. Values were obtained by conducting random-effect forest plots. Our literature search identified 2022 records, of which 8 studies were included. A total of 3563 participants with a positive FIT were included. Use of OACs was associated with a PPVAN of 37.6% (95% CI 33.9 to 41.4) compared with 40.3% (95% CI 38.5 to 42.1) for non-users (p=0.75). Pooled PPVAN in aspirin/NSAID users was 38.2% (95% CI 33.8 to 42.9) compared with 39.4% (95% CI 37.5 to 41.3) for non-users (p=0.59). FIT accuracy is not affected by OACs and aspirin/NSAIDs use. Based on the current literature, withdrawal of OACs or NSAIDs before FIT screening is not recommended. Future studies should focus on duration of use, dosage and classes of drugs in association with accuracy of FIT to conduct more specific guideline recommendations.

Attendance and yield over three rounds of population-based fecal immunochemical test screening.

Fecal immunochemical test (FIT) screening for colorectal cancer (CRC) requires timely successive rounds for an optimal preventive effect. However, data on attendance and trend in yield over multiple rounds of FIT screening are limited. We therefore conducted a consecutive third round of FIT screening in a population-based CRC screening trial. Average-risk subjects aged 50-74 years were approached for three rounds of 1-sample FIT (OC-sensor) screening. Subjects with a hemoglobin level ≥50 ng/ml (≥10 μg Hb/g) feces were referred for colonoscopy. Subjects with a positive FIT in previous rounds were not re-invited for FIT screening. In the first round, 7,501 subjects were invited. The participation rate was 62.6% in the first round, 63.2% in the second round, and 68.3% in the third round (P<0.001). In total, 73% (5,241/7,229) of all eligible subjects participated in at least one of three rounds. The positivity rate was significantly higher in the first (8.4%) round compared with the second (6.0%) and third (5.7%) screening rounds (P<0.001). The detection rate of advanced neoplasia (AN) declined from the first round to subsequent rounds (round 1: 3.3%; round 2: 1.9%; and round 3: 1.3%; P<0.001). The positive predictive value for AN was 40.7% in the first screening round, 33.2% in the second screening round, and 24.0% in the third screening round (P<0.001). Repeated biennial FIT screening is acceptable with increased participation in successive screening rounds, and >70% of all eligible subjects participating at least once over three rounds. The decline in screen-detected AN over three screening rounds is compatible with a decreased prevalence of AN as a result of repeated FIT screening. These findings provide strong evidence for the effectiveness of FIT screening and stress the importance of ongoing research over multiple screening rounds.

Effect of oral anticoagulants on the outcome of faecal immunochemical test

Background:We aimed to evaluate whether oral anticoagulants (OACs) alter faecal immunochemical test (FIT) performance in average-risk colorectal cancer (CRC) screening.Methods:Individuals aged 50–69 years were invited to receive one FIT sample (cutoff 75 ng ml–1) between November 2008 and June 2011.Results:Faecal immunochemical test was positive in 9.3% (21 out of 224) of users of OAC and 6.2% (365 out of 5821) of non-users (P-trend=0.07). The positive predictive value (PPV) for advanced neoplasia (AN) in non-users was 50.4% vs 47.6% in users (odds ratio, 0.70; 95% CI, 0.3–1.8; P=0.5). The PPV for AN in OAC more antiplatelets (aspirin or clopidogrel) was 75% (odds ratio, 2; 95% CI, 0.4–10.8; P=0.4).Conclusions:Oral anticoagulant did not significantly modify the PPV for AN in this population-based colorectal screening program. The detection rate of advanced adenoma was higher in the combination OAC more antiplatelets.

Effect of Aspirin and Antiplatelet Drugs on the Outcome of the Fecal Immunochemical Test

ObjectiveTo evaluate the effect of aspirin and nonaspirin antiplatelet agents (NAAAs) on the performance of the fecal immunochemical test (FIT). Participants and MethodsWe performed a post hoc analysis of results from a clinical trial that involved 28,696 asymptomatic average-risk men and women aged 50 to 69 years invited to participate in a colorectal cancer screening program with FIT between November 1, 2008, and June 31, 2011. ResultsThe test was returned by 6390 individuals (22.3%), of whom 5821 (91.1%) reported not using antiplatelet drugs (nonusers group) and 569 (8.9%) reported using these drugs at the time of testing (users group). The FIT result was positive in 48 of 569 users (8.4%) and 365 of 5821 nonusers (6.3%) (P=.05). A positive FIT result was found in 7.3% (28/384) of aspirin users, 7.1% (10/140) of NAAA users, and 22.2% (10/45) of those undergoing dual antiplatelet therapy (DAPT) (aspirin plus an NAAA). The DAPT subgroup had a significantly higher positive FIT rate than the nonuser group (odds ratio, 3.5; 95% CI, 1.7-7.3; P<.05). The positive predictive value (PPV) for advanced neoplasia (AN) in nonusers was 50.4% vs 50.0% in users (P = .40). The PPV for AN was 57.0% in aspirin users, 30.0% in NAAA users, and 50.0% in DAPT users, without statistically significant differences between the user and nonuser groups. ConclusionThe use of DAPT increased the rate of positive FIT results. Use of aspirin, NAAAs, or both did not modify the PPV for AN in this population-based colorectal screening program. Trial Registrationclinicaltrials.gov Identifier: NCT00906997