Effects of Attendance to an Organized Fecal Immunochemical Test Screening Program on the Risk of Colorectal Cancer: An Observational Cohort Study.

BACKGROUND & AIMS: This cohort study compared colorectal cancer (CRC) incidence and mortality between people who participated in an Italian regional biennial fecal immunochemical test (FIT) screening program and people who did not. METHODS: The program started in 2005. The target population included over 1,000,000 people aged 50 to 69 years. The FIT was a one-sample OC-Sensor (Eiken Chemical Co, Tokyo, Japan) (cutoff, ≥20 µg hemoglobin/g feces). The average annual response rate to invitation was 51.4%. The records of people invited up to June 2016 were extracted from the screening data warehouse. Attenders were subjects who responded to the first 2 invitations or to the single invitation sent them before they became ineligible. Non-attenders were subjects who did not respond to any of these invitations. The records were linked with the regional CRC registry. People registered up to December 2016 were identified. Self-selection-adjusted incidence rate ratios (IRRs) and incidence-based CRC mortality rate ratios (MRRs) for attenders to non-attenders, with 95% confidence intervals (CIs), were calculated. RESULTS: The cohort generated 2,622,131 man-years and 2,887,845 woman-years at risk with 4490 and 3309 CRC cases, respectively. The cohort of attenders was associated with an IRR of 0.65 (95% CI, 0.61-0.69) for men, 0.75 (95% CI, 0.70-0.80) for women and 0.69 (95% CI, 0.66-0.72) for both sexes combined. The self-selection-adjusted IRR was 0.67 (95% CI, 0.62-0.72) for men and 0.79 (95% CI, 0.72-0.88) for women. The IRR for stage I, II, III, and IV CRC was 1.35 (95% CI, 1.20-1.50), 0.61 (95% CI, 0.53-0.69), 0.60 (95% CI, 0.53-0.68) and 0.28 (95% CI, 0.24-0.32) for men and 1.64 (95% CI, 1.43-1.89), 0.60 (95% CI, 0.52-0.69), 0.73 (95% CI, 0.63-0.85) and 0.35 (95% CI, 0.30-0.42) for women. The overall incidence-based CRC MRR was 0.32 (95% CI, 0.28-0.37) for men, 0.40 (95% CI, 0.34-0.47) for women and 0.35 (95% CI, 0.31-0.39) for both sexes combined. The adjusted MRR was 0.35 (95% CI, 0.29-0.41) for men and 0.46 (95% CI, 0.37-0.58) for women. CONCLUSIONS: Attendance to a FIT screening program is associated with a CRC incidence reduction of 33% among men and 21% among women, and a CRC mortality reduction of 65% and 54%, respectively.

Proportional incidence of interval colorectal cancer in a large population-based faecal immunochemical test screening programme.

BACKGROUND: The European guidelines for quality assurance in colorectal cancer (CRC) screening recommend that interval cancer rate be expressed as a proportion of background incidence rate. AIM: To determine the crude and adjusted proportional incidence of interval CRC in an Italian regional two-yearly faecal immunochemical test (FIT) screening programme. METHODS: The programme (year of implementation, 2005) is targeted at over 1,000,000 people aged 50-69 years. The test is a one-sample OC-Sensor (Eiken Chemical Co., Tokyo, Japan). The study covered one-third of the regional area. Excerpts of 434,295 eligible negative FIT records dated 2005-2012 from 193,193 subjects were retrieved from the regional CRC screening data warehouse. By 31 December 2013, the cohort accumulated 198,302 man-years and 235,370 woman-years. Interval CRCs were identified by record-linkage with the local population-based cancer registry. Their number was divided by the expected number, estimated with age-period-cohort models, to obtain the proportional incidence. RESULTS: The proportional incidence of interval CRC for men and women was, respectively, 0.06 (95% confidence interval (CI), 0.04-0.09) and 0.17 (95% CI, 0.13-0.23) in the first interval year, and 0.21 (95% CI, 0.16-0.26) and 0.28 (95% CI, 0.22-0.36) in the second year. CONCLUSIONS: The results were acceptable and in line with previous studies.

Colonoscopic surveillance of first-degree relatives of colorectal cancer patients in a faecal occult blood screening programme.

BACKGROUND: In some Italian areas, colonoscopic surveillance of first-degree relatives (FDRs) of colorectal cancer (CRC) patients is provided as a part of local population-based faecal occult blood test (FOBT) screening programmes. The objective of the present study was to assess the feasibility and early results of this surveillance model. METHODS: Data from district screening centres were used to evaluate the process of identification and selection of eligible FDRs (residence in the Emilia-Romagna Region, age 40-75 years, no recent colonoscopy) of screen-detected CRC patients and the detected prevalence of disease. The probability for an FDR to undergo colonoscopy and to be diagnosed with CRC and advanced adenoma was estimated using the Kaplan-Meier method. The sex- and age-standardised ratio of detected prevalence to that expected based on results from a colonoscopy screening study of the Italian general population was estimated. RESULTS: Between 2005 and 2011, 9319 FDRs of 2437 screen-detected CRC patients (3.8 per patient) were identified and contacted. Their likelihood of being eligible for, and accepting, colonoscopy was 0.11 (95% confidence interval: 0.11-0.12). Among the 926 subjects undergoing colonoscopy, the prevalence of previous negative screening FOBT was 63%. Eleven CRCs (1.2%) and 100 advanced adenomas (10.8%) were detected. The standardised ratio of detected prevalence to that expected was 0.91 (95% confidence interval: 0.19-2.66) for CRC and 1.48 (1.04-2.05) for advanced adenoma. CONCLUSIONS: The procedure of selection of FDRs was extremely ineffective. Due to previous negative screening tests, the prevalence of disease was less than expected. A population-based FOBT screening programme is a highly unsuitable setting for the provision of surveillance to FDRs of CRC patients.