Short-term impact of the COVID-19 pandemic on a population-based screening program for colorectal cancer in Catalonia (Spain).

The COVID-19 pandemic caused the suspension at all levels of the Catalan FIT-based CRC screening program on March 12, 2020. Screening invitations to FIT were resumed on September 1, 2020. We aimed to assess the short-term impact of the pandemic and describe strategies implemented to minimize harm by the disruption of the FIT-based CRC screening in the Metropolitan Area of Barcelona. We analyzed participation rate, colonoscopy adherence, time intervals to colonoscopy, detection rates, and advanced-stage cancers in 2019 and 2020. To identify perceived distress levels during the suspension of the screening we conducted a phone interview. As a result of the suspension, 43% of the individuals due for screening did not receive their invitation by December 31, 2020. A percent decrease of 5.1% in participation and of 8.9% in colonoscopy adherence among invitees between January-March was observed, with a recovery to 2019 levels when the screening activities were restarted. The time interval between a positive test to colonoscopy was longer in 2020 than in 2019. A decrease in advanced neoplasia rate and an increase in later stages of CRC were also observed. Individuals with a positive test did not report higher levels of perceived distress compared to those with a negative test. Although the disruption of screening had a temporary impact on participation and colonoscopy adherence, timing delay continues and a large backlog in the invitation of the target population remains. Thus, it is critical to implement strategies to minimize the long-term effects.

Role of community pharmacies in a population-based colorectal cancer screening program.

In Catalonia (Spain), population-based colorectal cancer (CRC) screening offers biennial fecal occult blood testing to men and women aged 50-69 years old. The program is organized in screening hubs, most of which use a pharmacy-based model to distribute and collect fecal immunochemical test (FIT) kits The comprehensive evaluation of CRC screening programs, which include the role and implications of pharmacy involvement, is essential to ensure program quality and identify areas for further improvement. The present study aimed to assess the adherence of community pharmacies to the CRC screening program and to analyze data on FIT kit distribution and collection in the Metropolitan area of Barcelona (Catalonia, Spain). Time to FIT completion was assessed by Kaplan-Meier estimation, and with the log-rank test. A Cox regression model was used to adjust for other variables associated with the completion of FIT such as sex, age, deprivation score index and previous screening behavior. Overall, 82.4% of pharmacies adhered with CRC screening program. Out of 82,902 FIT kits distributed to screening invitees 77,524 completed FIT kits were returned to pharmacies (93.5%) with a participation of 39.8% among the 193,766 invitees. From those who completed a FIT, the median time to return the kit was 3 days. FIT completion time was significantly lower among women, older age, high deprivation score index and previous CRC screening (p < 0.005). Our findings highlight the large involvement of community pharmacists with CRC screening program as well as a high quality in the process of FIT distribution and collection.

Heterogeneity of Moraxella isolates found in the nasal cavities of piglets.

BACKGROUND: Previous studies have shown that the genus Moraxella is commonly present in the nasal microbiota of swine. RESULTS: In this study, 51 isolates of Moraxella were obtained from nasal swabs from 3 to 4 week old piglets, which represented 26 different fingerprintings by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Whole 16S rRNA gene sequencing allowed the identification at species level of the Moraxella spp. isolates. The majority of the field strains were identified as Moraxella pluranimalium, but Moraxella porci was also detected. In addition, a cluster of 7 strains did not group with any described Moraxella species, probably representing a new species. Subsequent phenotypic characterization indicated that strains of Moraxella pluranimalium were mainly sensitive to serum complement, while the cluster representing the putative new species was highly resistant. Biofilm formation capacity was very variable among the Moraxella spp. isolates, while adherence to epithelial cell lines was similar among selected strains. Additionally, variability was also observed in the association of selected strains to porcine alveolar macrophages. Antimicrobial tests evidenced the existence of multidrug-resistance in the strains. CONCLUSIONS: In summary, phenotypic characterization revealed heterogeneity among Moraxella strains from the nasal cavity of piglets. Strains with pathogenic potential were detected as well as those that may be commensal members of the nasal microbiota. However, the role of Moraxella in porcine diseases and health should be further evaluated.

Urban Wild Boars and Risk for Zoonotic Streptococcus suis, Spain.

Urban wild boars (Sus scrofa) from Barcelona, Spain, harbor great diversity of Streptococcus suis strains, including strains with the cps2 gene and with the same molecular profile as local human cases. The increasing trend of potential effective contacts for S. suis transmission is of public health concern.

Incidence of advanced neoplasia during surveillance in high- and intermediate-risk groups of the European colorectal cancer screening guidelines.

Background and study aims: 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. Patients and methods: 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. Results: The study included 5401 patients (3379 intermediate risk, 2022 high risk). Endoscopic surveillance was performed in 65.5 % of the patients (2.8 ±â€Š1 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). Conclusions: 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.

Changes in macrophage phenotype after infection of pigs with Haemophilus parasuis strains with different levels of virulence.

Haemophilus parasuis is a colonizer of healthy piglets and the etiological agent of Glässer's disease. Differences in virulence among strains of H. parasuis have been widely observed. In order to explore the host-pathogen interaction, snatch-farrowed colostrum-deprived piglets were intranasally infected with 4 strains of H. parasuis: reference virulent strain Nagasaki, reference nonvirulent strain SW114, field strain IT29205 (from a systemic lesion and virulent in a previous challenge), and field strain F9 (from the nasal cavity of a healthy piglet). At different times after infection, two animals of each group were euthanized and alveolar macrophages were analyzed for the expression of CD163, CD172a, SLA I (swine histocompatibility leukocyte antigen I), SLA II, sialoadhesin (or CD169), and CD14. At 1 day postinfection (dpi), virulent strains induced reduced expression of CD163, SLA II, and CD172a on the surfaces of the macrophages, while nonvirulent strains induced increased expression of CD163, both compared to noninfected controls. At 2 dpi, the pattern switched into a strong expression of CD172a, CD163, and sialoadhesin by the virulent strains, which was followed by a steep increase in interleukin 8 (IL-8) and soluble CD163 in serum at 3 to 4 dpi. The early increase in surface expression of CD163 induced by nonvirulent strains went along with higher levels of IL-8 in serum than those induced by virulent strains in the first 2 days of infection. Alpha interferon (IFN-α) induction was observed only in animals infected with nonvirulent strains. Overall, these results are compatible with a delay in macrophage activation by virulent strains, which may be critical for disease production.

Colonoscopy quality assessment in a mass population screening programme based on faecal occult blood test.

BACKGROUND AND AIM: the success of colorectal cancer (CRC) screening programmes largely depends on the quality of the events, processes and outcomes and therefore, quality assurance of endoscopy is an essential component. The quality indicators for colonoscopy in a screening programme setting are different from those performed in symptomatic people. The objective of this study was to report the main quality indicators of colonoscopies performed after a positive faecal occult blood test (FOBT) in a CRC screening programme in Catalonia. METHODS: the period of study includes three rounds of the CRC screening programme from June 2006 to July 2013. Two types of FOBT were used: a qualitative biochemical guaiac-based test (gFOBT) and a quantitative immunochemical test (FIT). Quality indicators analysed in this study were compared to recommended colonoscopy standards from the published guidelines. RESULTS: during the study period, 1,806 colonoscopies were performed in 1,691 individuals with a positive FOBT. All indicators were within the standard except waiting time to colonoscopy. Caecal intubation rate was 95.6 % and adequate bowel cleansing 93.6 %. Adenoma detection rate was better using FIT than gFOBT, 30.7 and 3.8 per 1,000 screenees, respectively. Cancer detection rate was also greater using FIT. Nearly 62 % of cancers were diagnosed at an early stage. The overall complication rate was 10.7 ‰. CONCLUSION: although the majority of results reached the recommended standards, some areas have been identified for quality enhancement. Continuous monitoring of quality indicators is essential for improving the current effectiveness of CRC screening programmes.

Metabolic insights and background from naturally affected pigs during Streptococcus suis outbreaks.

Streptococcus suis (S. suis) is an endemic zoonotic pathogen still lacking adequate prevention in pigs. The present case study looked back to the occurrence and consequences of S. suis outbreaks in our swine research facilities in search of new metabolic and physiological insight. From a series of outbreaks, a dataset was created including 56 pigs sampled during disease detection based on clinical signs. Pigs suspected with S. suis infection were defined as diseased (n = 28) and included pigs defined as neurologically diseased (n = 20) when severe neurological signs (central nervous system dysfunctions, i.e., opisthotonos, ataxia, and generalized tremor) were observed. Another set of 28 pigs included respective pen mates from each case and were defined as control. Representative deaths were confirmed to be caused by S. suis. Tonsillar swabs were collected and analyzed by quantitative polymerase chain reaction (qPCR) for total bacteria, total S. suis, and S. suis serotypes (SS) 2 (and/or 1/2) and 9. Blood and sera were analyzed to quantify blood gases, minerals, and S. suis reactive immunoglobulins against current isolates. Data collected included litter sibling associations, birth and weaning body weight (BW), and average daily gain (ADG) 7 d after the disease detection. In general, the disease increased pH, sO2 and the incidence of alkalosis, but reduced pCO2, glucose, Ca, P, Mg, K, and Na in blood/serum compared to control. The SS2 (and/or SS1/2) prevalence was significantly (P < 0.05) increased in neurologically diseased pigs and its relative abundance tended (P < 0.10) to increase in tonsils. In contrast, the relative abundance of total S. suis was lower (P > 0.05) in diseased pigs than control pigs. Levels of S. suis reactive IgG2 were lower, but IgM were higher (P < 0.03) in neurologically affected pigs compared to control. Furthermore, there was an increased proportion of sibling pigs that were diseased compared to control. In conclusion, our results evidence that naturally affected pigs were associated to average performing pigs without any predisease trait to highlight but a sow/litter effect. Besides, neurologically affected pigs had increased S. suis (SS2 and/or 1/2) prevalence and relative abundance, a respiratory alkalosis profile, and mineral loss.

VtaA8 and VtaA9 from Haemophilus parasuis delay phagocytosis by alveolar macrophages.

Haemophilus parasuis, a member of the family Pasteurellaceae, is a common inhabitant of the upper respiratory tract of healthy pigs and the etiological agent of Glässer's disease. As other virulent Pasteurellaceae, H. parasuis can prevent phagocytosis, but the bacterial factors involved in this virulence mechanism are not known. In order to identify genes involved in phagocytosis resistance, we constructed a genomic library of the highly virulent reference strain Nagasaki and clones were selected by increased survival after incubation with porcine alveolar macrophages (PAM). Two clones containing two virulent-associated trimeric autotransporter (VtaA) genes, vtaA8 and vtaA9, respectively, were selected by this method. A reduction in the interaction of the two clones with the macrophages was detected by flow cytometry. Monoclonal antibodies were produced and used to demonstrate the presence of these proteins on the bacterial surface of the corresponding clone, and on the H. parasuis phagocytosis-resistant strain PC4-6P. The effect of VtaA8 and VtaA9 in the trafficking of the bacteria through the endocytic pathway was examined by fluorescence microscopy and a delay was detected in the localization of the vtaA8 and vtaA9 clones in acidic compartments. These results are compatible with a partial inhibition of the routing of the bacteria via the degradative phagosome. Finally, antibodies against a common epitope in VtaA8 and VtaA9 were opsonic and promoted phagocytosis of the phagocytosis-resistant strain PC4-6P by PAM. Taken together, these results indicate that VtaA8 and VtaA9 are surface proteins that play a role in phagocytosis resistance of H. parasuis.

Diagnostic Performance of a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program According to Ambient Temperature and Humidity.

Exposure of the fecal immunochemical test (FIT) to different ambient temperatures and humidity is unavoidable in population-based screening programs in Southern European countries, and it could lead to a decrease in target colorectal lesions. The objective was to evaluate the effect of ambient temperature and humidity on the FIT sensitivity in a population-based screening program for colorectal cancer (CRC) using an ecological design. The retrospective cohort included individuals aged 50−69 years who participated in CRC screening (Barcelona) from 2010−2015, and were followed until 2017 to identify interval CRCs. The positivity rate, and detection rates for advanced polyps and CRC were compared according to ambient temperature, humidity, and quarters of the year. A positive FIT was defined as the detection of ≥20 µg Hb/g in feces. The monthly ambient temperature and humidity were recorded on the day that the FIT was performed. In total, 92,273 FIT results from 53,860 participants were analyzed. The FIT positivity rate was lower at >24 °C than at ≤24 °C (p = 0.005) but was not affected by humidity. The temperature's impact on positivity did not lead to a decrease in the FIT detection rate for advanced neoplasia or the interval cancer detection rate in a program where the samples were refrigerated until the analysis and screening invitations were discontinued in July and August.

Positive impact of a faecal-based screening programme on colorectal cancer mortality risk.

INTRODUCTION: The effectiveness of colorectal cancer (CRC) screening programs is directly related to participation and the number of interval CRCs. The objective was to analyse specific-mortality in a cohort of individuals invited to a CRC screening program according to type of CRC diagnosis (screen-detected cancers, interval cancers, and cancers among the non-uptake group). MATERIAL AND METHODS: Retrospective cohort that included invitees aged 50-69 years of a CRC screening program (target population of 85,000 people) in Catalonia (Spain) from 2000-2015 with mortality follow-up until 2020. A screen-detected CRC was a cancer diagnosed after a positive faecal occult blood test (guaiac or immunochemical); an interval cancer was a cancer diagnosed after a negative test result and before the next invitation to the program (≤24 months); a non-uptake cancer was a cancer in subjects who declined screening. RESULTS: A total of 624 people were diagnosed with CRC (n = 265 screen-detected, n = 103 interval cancers, n = 256 non-uptake). In the multivariate analysis, we observed a 74% increase in mortality rate in the group with interval CRC compared to screen-detected CRC adjusted for age, sex, location and stage (HR: 1.74%, 95% CI:1.08-2.82, P = 0.02). These differences were found even when we restricted for advanced-cancers participants. In the stratified analysis for type of faecal occult blood test, a lower mortality rate was only observed among FIT screen-detected CRCs. CONCLUSION: CRC screening with the FIT was associated with a significant reduction in CRC mortality.

Text messaging as a tool to improve cancer screening programs (M-TICS Study): A randomized controlled trial protocol.

BACKGROUND: Short message service (SMS) based interventions are widely used in healthcare and have shown promising results to improve cancer screening programs. However, more research is still needed to implement SMS in the screening process. We present a study protocol to assess the impact on health and economics of three targeted SMS-based interventions in population-based cancer screening programs. METHODS/DESIGN: The M-TICs study is a randomized controlled trial with a formal process evaluation. Participants aged 50-69 years identified as eligible from the colorectal cancer (CRC) and breast cancer (BC) screening program of the Catalan Institute of Oncology (Catalonia, Spain) will be randomly assigned to receive standard invitation procedure (control group) or SMS-based intervention to promote participation. Two interventions will be conducted in the CRC screening program: 1) Screening invitation reminder: Those who do not participate in the CRC screening within 6 weeks of invite will receive a reminder (SMS or letter); 2) Reminder to complete and return fecal immunochemical test (FIT) kit: SMS reminder versus no intervention to individuals who have picked up a FIT kit at the pharmacy and they have not returned it after 14 days. The third intervention will be performed in the BC screening program. Women who had been screened previously will receive an SMS invitation or a letter invitation to participate in the screening. As a primary objective we will assess the impact on participation for each intervention. The secondary objectives will be to analyze the cost-effectiveness of the interventions and to assess participants' perceptions. EXPECTED RESULTS: The results from this randomized controlled trial will provide important empirical evidence for the use of mobile phone technology as a tool for improving population-based cancer screening programs. These results may influence the cancer screening invitation procedure in future routine practice. TRIAL REGISTRATION: Registry: NCT04343950 (04/09/2020); clinicaltrials.gov.

Proton-pump inhibitors are associated with a high false-positivity rate in faecal immunochemical testing.

BACKGROUND: False-positivity rates in faecal immunochemical test (FIT) can be affected by drug exposure. We aimed to assess the association between proton pump inhibitors (PPI) consumption and false positive (FP) results in a colorectal cancer (CRC) screening programme using electronic prescription records. METHODS: A retrospective cohort study within a population-based screening program for CRC from 2010 to 2016 was performed. Participants with a conclusive FIT result and with prescription electronic data were included. An FP result was defined as having a positive FIT (≥ 20 µg haemoglobin/g faeces) and a follow-up colonoscopy without intermediate or high-risk lesions or CRC. Screening data were anonymously linked to the public data analysis program for health research and innovation (PADRIS) database that recorded patient diseases history and reimbursed medication. PPI exposure was defined as having retrieved at least one dispensation of PPI three months prior to the FIT. RESULTS: A total of 89,199 tests (of 46,783 participants) were analysed, 4824 (5.4%) tested positive and the proportion of FP was 53.5%. Overall, 17,544 participants (19.7%) were PPI users prior to FIT performance. PPI exposure increased the probability of obtaining an FP FIT result from 50.4 to 63.3% (adjusted OR 1.39; 95% CI 1.18-1.65). Nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, antibiotics, and laxatives were also associated with an FP result. The effect of PPI was independent and showed a synergistic interaction with nonsteroidal anti-inflammatory drugs. CONCLUSION: PPIs increase FIT positivity at the expense of FP results. The recommendation to avoid their use before FIT performance could reduce up to 3% of colonoscopies and 9% of FP results.

Longitudinal Adherence to Immunochemical Fecal Occult Blood Testing vs Guaiac-based FOBT in an Organized Colorectal Cancer Screening Program.

Longitudinal adherence is a critical component of the efficacy of stool-based screening programs because they should be repeated every 1-2 years. Few data have been published on the uptake in multiple rounds of fecal occult blood test-based (FOBT) colorectal cancer (CRC) screening. We calculated two measures of longitudinal adherence to biennial FOBT (guaiac fecal occult blood test:gFOBT or fecal immunochemical test:FIT) to better understand its impact on the programmatic effectiveness of a population-based CRC screening program (2000-2017). Ongoing population-based CRC program of men and women aged 50-69 years. Variables: Age at first CRC screening invitation, sex, number of screening invitations, number of screens, deprivation score, and uptake rate. Logistic regression models were used to assess the independent effect of sex, age at first invitation, deprivation, and the type of screening test offered on adherence. The uptake rate for guaiac fecal occult blood test (gFOBT) was 23.9%, and for the fecal immunochemical test (FIT), it was 37.4%. The overall rate of consistently screened invitees after seven rounds of screening was 14.2%, being 20.6% for those individuals who used FIT and 14.3% for those who used gFOBT. Factors associated with continued participation (consistent vs. inconsistent screenees) showed that the longitudinal adherence was associated with age, screening test used, and number of invitations. Continued participation was lower in individuals who were screened using FIT than among those screened using gFOBT [OR, 0.68; 95% confidence interval (CI), 0.57-0.81]. The overall rate of consistently screened invitees for colorectal cancer screening was higher with FIT than gFOBT. Studying the rate of individuals being current for screening may help to anticipate potential benefits before the long-term outcome data are available.

False-Positive Results in a Population-Based Colorectal Screening Program: Cumulative Risk from 2000 to 2017 with Biennial Screening.

BACKGROUND: The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program. METHODS: Retrospective cohort study, which included participants ages 50 to 69 years of a colorectal cancer screening program in Catalonia, Spain. During this period, 2 FOBTs were used (guaiac and immunochemical). A discrete-time survival model was performed to identify risk factors of receiving a positive FOBT with no high-risk adenoma or colorectal cancer in the follow-up colonoscopy. We estimated the probability of having at least 1 FP over 7 screening rounds. RESULTS: During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC95%: 14.6%-18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35-8.51] and a 12.4% (95% CI, 11.00-13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening, and number of personal screens were factors associated with an FP result among screenees. CONCLUSIONS: The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low. IMPACT: It is useful to determine the cumulative FP risk in cancer screening for both advising individuals and for health resources planning.

Identification of a surface epitope specific of virulent strains of Haemophilus parasuis.

Haemophilus parasuis is a bacterium from the Pasteurellaceae family that comprises strains of different degree of virulence. Non-virulent strains are considered components of the upper respiratory tract microbiota, while virulent strains can invade systemic organs and cause fibrinous polyserositis (Glässer's disease). Genomic comparison of virulent and non-virulent strains led to the identification of a family of genes differentially associated to virulence, the virulence-associated trimeric autotransporters (vtaA). Monoclonal antibody 69C6 reacted with the surface of virulent strains and has allowed now the identification of an epitope in the C terminus of the passenger domain of the VtaAs from virulent strains. Protein modelling indicated that the epitope is probably exposed, although sera from pigs vaccinated with the passenger domain of VtaA9 and from convalescent animals did not react with the 69C6 epitope. Induction of antibodies against the 69C6 epitope by vaccination would allow a response targeting specifically virulent strains of H. parasuis.

False-negative rate cannot be reduced by lowering the haemoglobin concentration cut-off in colorectal cancer screening using faecal immunochemical test.

The aim of this study was to analyse false-negative (FN) results of the faecal immunochemical test (FIT) and its determinants in a colorectal cancer screening programme in Catalonia. We carried out a cross-sectional study among 218 screenees with a negative FIT result who agreed to undergo a colonoscopy. A false-negative result was defined as the detection, at colonoscopy, of intermediate/high-risk polyps or colorectal cancer in a patient with a previous negative FIT (<20 µgHb/g). Multivariate logistic regression models were constructed to identify sociodemographic (sex, age) and screening variables (quantitative faecal haemoglobin, colonoscopy findings) related to FN results. Adjusted odds ratios and their 95% confidence intervals were estimated. There were 15.6% FN FIT results. Faecal haemoglobin was undetected in 45.5% of these results and was below 4 µgHb/g in 94.0% of the individuals with a FN result. About 60% of the lesions were located in the proximal colon, whereas the expected percentage was 30%. Decreasing the positivity threshold of FIT does not increase the detection rate of advanced neoplasia, but may increase the costs and potential adverse effects.

Colorectal Cancer Screening Programme in Spain: Results of Key Performance Indicators After Five Rounds (2000-2012).

Effective quality assurance is essential in any screening programme. This article provides a unique insight into key quality indicators of five rounds of the first population-based colorectal cancer screening programme implemented in Spain (2000-2012), providing the results according to the type of screening (prevalent or first screen and incident or subsequent screen) and test (guaiac or immunochemical). The total crude participation rate increased from 17.2% (11,011) in the first round to 35.9% (22,988) in the last one. Rescreening rate was very high (88.6% in the fifth round). Positivity rate was superior with the faecal immunochemical test (6.2%) than with the guaiac-based test (0.7%) (p < 0.0001) and detection rates were also better with the immunochemical test. The most significant rise in detection rate was observed for high risk adenoma in men (45.5 per 1,000 screened). Most cancers were diagnosed at an early stage (61.4%) and there was a statistically significant difference between those detected in first or subsequent screening (52.6% and 70.0% respectively; p = 0.024). The availability of these results substantially improves data comparisons and the exchange of experience between screening programmes.

[Interval cancers and episode sensitivity in population-based screening programmes for colorectal cancer: a systematic review]. / Cánceres de intervalo y sensibilidad de los programas poblacionales de cribado de cáncer colorrectal.

OBJECTIVE: To describe interval cancers (IC) and the sensitivity of colorectal cancer (CRC) screening programmes. METHODS: A systematic review of the literature was conducted through a MEDLINE (PubMed) search. The search strategy combined the terms 'interval cancer', 'false negative', 'mass screening', 'screening' 'early detection of cancer', 'colorectal cancer' and 'bowel cancer'. Inclusion criteria consisted of population-based screening programmes, original articles written in English or Spanish and publication dates between 1999/01/01 and 2015/02/28. A narrative synthesis of the included articles was performed detailing the characteristics of the screening programmes, the IC rate, and the information sources used in each study. RESULTS: Thirteen articles were included. The episode sensitivity of CRC screening programmes ranged from 42.2% to 65.3% in programmes using the guaiac test and between 59.1% and 87.0% with the immunochemical test. We found a higher proportion of women who were diagnosed with IC and these lesions were mainly located in the proximal colon. CONCLUSION: There is wide variability in the IC rate in CRC programmes. To ensure comparability between programmes, there is a need for consensus on the working definition of IC and the methods used for their identification and quantification.

Fecal hemoglobin concentration as a measure of risk to tailor colorectal cancer screening: are we there yet?

The aim of this paper was to examine the distribution of fecal hemoglobin (f-Hb) concentration in a Spanish colorectal cancer screening population according to sociodemographic characteristics and analyze whether f-Hb was associated with clinical outcomes (type of lesion and its location). From September 2009 to November 2012, we sent 77,744 invitations to individuals aged 50-69 years to provide one sample of feces. f-Hb was measured on samples from 27,606 screenees (35.5%). Colonoscopy findings and pathology data were collected on the 1406 screenees with f-Hb greater than 100 ng Hb/ml (20 mg Hb/g feces). The Mann-Whitney U-test and the Kruskal-Wallis test were used to compare f-Hb (median) according to sociodemographic variables, clinical outcomes, and histological features of adenomas. f-Hb from greater than 100 ng Hb/ml was categorized into quartiles. Regression models were used to determine whether f-Hb was a risk predictor of colorectal lesions. f-Hb was associated directly with the severity of the colorectal lesions. An overlap between individuals with a negative colonoscopy and those with a low-risk adenoma was observed. High-grade dysplasia, villous histology, distal location, and increasing size were all features associated with an increased f-Hb level. f-Hb could be used in individual risk assessment to determine surveillance strategies for colorectal cancer screening.