Retrospective cohort study: Risk of gastrointestinal cancer in a symptomatic cohort after a complete colonoscopy: Role of faecal immunochemical test

BACKGROUND: Faecal immunochemical test (FIT) has been recommended to assess symptomatic patients for colorectal cancer (CRC) detection. Nevertheless, some conditions could theoretically favour blood originating in proximal areas of the gastrointestinal tract passing through the colon unmetabolized. A positive FIT result could be related to other gastrointestinal cancers (GIC). AIM: To assess the risk of GIC detection and related death in FIT-positive symptomatic patients (threshold 10 µg Hb/g faeces) without CRC. METHODS: Post hoc cohort analysis performed within two prospective diagnostic test studies evaluating the diagnostic accuracy of different FIT analytical systems for CRC and significant colonic lesion detection. Ambulatory patients with gastrointestinal symptoms referred consecutively for colonoscopy from primary and secondary healthcare, underwent a quantitative FIT before undergoing a complete colonoscopy. Patients without CRC were divided into two groups (positive and negative FIT) using the threshold of 10 µg Hb/g of faeces and data from follow-up were retrieved from electronic medical records of the public hospitals involved in the research. We determined the cumulative risk of GIC, CRC and upper GIC. Hazard rate (HR) was calculated adjusted by age, sex and presence of significant colonic lesion. RESULTS: We included 2709 patients without CRC and a complete baseline colonoscopy, 730 (26.9%) with FIT = 10 µgr Hb/gr. During a mean time of 45.5 ± 20.0 mo, a GIC was detected in 57 (2.1%) patients: An upper GIC in 35 (1.3%) and a CRC in 14 (0.5%). Thirty-six patients (1.3%) died due to GIC: 22 (0.8%) due to an upper GIC and 9 (0.3%) due to CRC. FIT-positive subjects showed a higher CRC risk (HR 3.8, 95%CI: 1.2-11.9) with no differences in GIC (HR 1.5, 95%CI: 0.8-2.7) or upper GIC risk (HR 1.0, 95%CI: 0.5-2.2). Patients with a positive FIT had only an increased risk of CRC-related death (HR 10.8, 95%CI: 2.1-57.1) and GIC-related death (HR 2.2, 95%CI: 1.1-4.3), with no differences in upper GIC-related death (HR 1.4, 95%CI: 0.6-3.3). An upper GIC was detected in 22 (0.8%) patients during the first year. Two variables were independently associated: anaemia (OR 5.6, 95%CI: 2.2-13.9) and age = 70 years (OR 2.7, 95%CI: 1.1-7.0). CONCLUSION: Symptomatic patients without CRC have a moderate risk increase in upper GIC, regardless of the FIT result. Patients with a positive FIT have an increased risk of post-colonoscopy CRC

Colorectal cancer screening: strategies to select populations with moderate risk for disease Cribado del cáncer colorrectal: estrategias para seleccionar a poblaciones con un riesgo moderado para esta enfermedad

Objective: to analyse the association between rectal bleeding or a family history of colorectal cancer (CRC) and the results obtained in two rounds of a CRC screening pilot programme performed in L'Hospitalet, Barcelona, Spain. Subjects: males and females (50-69 years) were the target population. Together with the invitation letter, they received a questionnaire in which they were askaed about rectal bleeding, family history of CRC and related neoplasms. The screening test was a guaiac-based faecal occult blood test (FOBT), and colonoscopy for positive tests. Results: 25,829 FOBT were performed in 18,405 individuals. Information on rectal bleeding and a family history of CRC were obtained for 9,849 and 9,865 cases, respectively. Male sex (OR = 1.32), 60-69 years of age (OR = 1.48), rectal bleeding (OR = 1.84) and history of CRC (OR = 1.54) were independent predictors of positive FOBT. With regard to colonoscopy, a greater risk of diagnosing advanced neoplasm was observed among men (OR = 2.47) and subjects with a family history of CRC (OR = 1.98). Conclusions: CRC screening programmes must have instruments that make it possible to select the candidate population and the possibility of offering a study suited to the risk of individuals who are not susceptible to population screening by means of FOBT

Long-Term Prediction of the Demand of Colonoscopies Generated by a Population-Based Colorectal Cancer Screening Program.

OBJECTIVE: To estimate the long-term need for colonoscopies after a positive fecal immunochemical test (FIT) and post-polypectomy surveillance in the context of a population-based colorectal cancer (CRC) screening program. METHODS: A discrete-event simulation model was built to reproduce the process of CRC screening and post-polypectomy surveillance following European guidelines in a population of 100,000 men and women aged 50-69 years over a 20-year period. Screening consisted of biennial FIT and colonoscopy in participants with positive results. The model was mainly fed using data from the first and second rounds of a Spanish program (2010-2013). Data on post-polypectomy surveillance results were obtained from the literature. A probabilistic multivariate sensitivity analysis was performed on the effect of participation, FIT positivity, and adherence to surveillance colonoscopies. The main outcome variables were the number of colonoscopies after a positive FIT, surveillance colonoscopies, and the overall number of colonoscopies. RESULTS: An average yearly number of 1,200 colonoscopies after a positive FIT were predicted per 100,000 inhabitants with a slight increase to 1,400 at the end of the 20-year period. Surveillance colonoscopies increased to an average of 1,000 per 100,000 inhabitants in the long-term, showing certain stabilization in the last years of the 20-year simulation horizon. The results were highly sensitive to FIT positivity. ONCLUSIONS: Implementing a population-based CRC screening program will increase the demand for colonoscopies, which is expected to double in 20 years, mainly due to an increase in surveillance colonoscopies.Financial support for this study was provided to MC by grant number PI07/90357 from Instituto de Salud Carlos III-FEDER (www.isciii.es/) and number AP94422011 from Fundación Mutua Madrileña (www.fundacionmutua.es/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Roche Diagnostics International Ltd., a commercial company, provided support in the form of salaries for JM, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section