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BackgroundWhile it is known that a variety of factors (biological, behavioural and interventional) play a major role in the health of individuals and populations, the importance of the role of social determinants is less clear. The effect of social inequality on population-based screening for colorectal cancer (CRC) could limit the value of such programmes. The present study aims to determine whether such inequalities exist.MethodsData was obtained from the population-based screening programme administered in the Autonomous Community of the Basque Country, Spain, with a target population aged 50 to 69, first invited to participate between 2009 and 2011. The magnitude of inequality was analysed using the odds ratio (taking the least disadvantaged socioeconomic quintile as the reference population), the population attributable risk and the relative index of inequality, based on the regression, which is the ratio of the rates in the most and least disadvantaged socioeconomic groups.ResultsThe target population comprised 242,394 people, with the test kit successfully sent to 95.1 % (230,510). The overall response rate was 64.3 % (67.1 in women and 61.4 % men).Among women, the highest participation was in the third quintile (71.5 %) and the lowest in the first – the least disadvantaged (65.7 %). The lowest and highest rates of people with identified lesions were in the second and fourth quintiles (14.7/1000 and 17.0/1000 respectively).Among men, the response rate was lowest in the fifth – most disadvantaged – quintile (60.2 %). The highest rate of identified lesions was in the fifth quintile; 38 % higher than the first (55.7/1000 compared to 41.0/1000).ConclusionsSex and socioeconomic group influence the rate of participation in the CRC programme and the rate of lesions found in the participants.Any public health programme is morally and ethically obliged to strive for equity and effectiveness. Improving participation of men and socially disadvantaged groups should be taken in account.

The European guidelines for quality assurance in colorectal cancer (CRC) screening have established high-risk (≥ 5 adenomas or an adenoma ≥ 20 mm) and intermediate-risk (3 - 4 adenomas or at least one adenoma 10 - 19 mm in size, or villous histology, or high grade dysplasia) groups with different endoscopic surveillance intervals. The aim of this study was to evaluate the difference in the incidence of advanced neoplasia (advanced adenoma or CRC) between the two risk groups. This retrospective group study included patients meeting high- or intermediate-risk criteria for adenomas detected in CRC screening programs and the COLONPREV study before European guidelines were adopted in Spain (June 2011) with a 3-year surveillance recommendation according to Spanish guidelines. The primary outcome measure was the incidence of advanced neoplasia in patients undergoing surveillance. The secondary outcome measure was the CRC incidence. We used an adjusted proportional hazards regression model to control confounding variables. The study included 5401 patients (3379 intermediate risk, 2022 high risk). Endoscopic surveillance was performed in 65.5 % of the patients (2.8 ± 1 years). The incidence of advanced neoplasia in the high- and intermediate-risk groups was 16.0 % (59.0 cases/1000 patient-years) and 12.3 % (41.2 cases/1000 patient-years), respectively. The CRC incidence was 0.5 % (1.4 cases/1000 patient-years) and 0.4 % (1 case/1000 patient-years), respectively. The advanced neoplasia and CRC attributable risk to the high risk group was of 3.7 % and 0.1 %, respectively. In the proportional hazards analysis, the risk of advanced neoplasia was greater in the high-risk group (hazard ratio [HR] 1.5, 95 % confidence interval [CI] 1.2 - 1.8), with no significant differences in the CRC incidence (HR 1.6, 95 %CI 0.6 - 3.8). Patients meeting high-risk criteria have a higher incidence of advanced neoplasia during endoscopic surveillance. No differences were found in the CRC incidence at a 3-year surveillance recommendation.

AIMTo assess proportions, related conditions and survival of interval cancer (IC).METHODSThe programme has a linkage with different clinical databases and cancer registers to allow suitable evaluation. This evaluation involves the detection of ICs after a negative faecal inmunochemical test (FIT), interval cancer FIT (IC-FIT) prior to a subsequent invitation, and the detection of ICs after a positive FIT and confirmatory diagnosis without colorectal cancer (CRC) detected and before the following recommended colonoscopy, IC-colonoscopy. We conducted a retrospective observational study analyzing from January 2009 to December 2015 1193602 invited people onto the Programme (participation rate of 68.6%).RESULTSTwo thousand five hundred and eighteen cancers were diagnosed through the programme, 18 cases of IC-colonoscopy were found before the recommended follow-up (43542 colonoscopies performed) and 186 IC-FIT were identified before the following invitation of the 769200 negative FITs. There was no statistically significant relation between the predictor variables of ICs with sex, age and deprivation index, but there was relation between location and stage. Additionally, it was observed that there was less risk when the location was distal rather than proximal (OR = 0.28, 95%CI: 0.20-0.40, P < 0.0001), with no statistical significance when the location was in the rectum as opposed to proximal. When comparing the screen-detected cancers (SCs) with ICs, significant differences in survival were found (P < 0.001); being the 5-years survival for SCs 91.6% and IC-FIT 77.8%.CONCLUSIONThese findings in a Population Based CRC Screening Programme indicate the need of population-based studies that continue analyzing related factors to improve their detection and reducing harm.

Background Colorectal cancer (CRC) is a major public health problem due to its incidence and mortality. Screening programmes help decrease its impact on the population through early detection. However, the uneven distribution of social determinants of health can cause inequalities. The aim of this study is to identify the social inequalities in the participation in CRC screening programmes. Methods A systematic review of the literature was carried out, searching in both health and social databases for papers published since 2000 in English, Spanish, Portuguese and French. The search strategies combined terms regarding screening, CRC, participation and social inequalities. Included papers were quantitative or qualitative primary studies analyzing gender and socioeconomic inequalities in the participation in CRC screening programmes implemented by public and private health-care providers and addressing 45- to 75-year-old population. Results A total of 96 studies, described in 102 articles, were included. Most were quantitative observational studies and analyzed population-based screening programmes. They were carried out mainly in the UK (n=29) and the USA (n=18). Participation in screening programmes varied from 1.1% to 82.8% using several methods. A total of 87 studies assessed participation by sex and one focussed on men, but only two provided an analysis from a gender perspective. Although men are at a higher risk of developing CRC, they generally were less likely to participate in screening programmes. Screening attendance was higher among the least deprived areas. Conclusions Gender and socioeconomic inequalities in CRC screening participation should be addressed through the design of tailored interventions with a multidimensional focus.