Prediction of the severity of colorectal lesion by fecal hemoglobin concentration observed during previous test in the French screening program

BACKGROUND The rate of positive tests using fecal immunochemical test(FIT)does not decrease with subsequent campaigns,but the positive predictive value of advanced neoplasia significantly decreases in subsequent campaign after a first negative test.A relationship between the fecal hemoglobin concentration(Fhb)and the opportunity to detect a colorectal cancer in subsequent campaign has been shown.AIM To predict the severity of colorectal lesions based on Fhb measured during previous colorectal cancer screening campaign.METHODS This etiological study included 293750 patients aged 50-74,living in Auvergne-Rhone-Alpes(France).These patients completed at least two FIT[test_((-1))and test_((0))]between June 2015 and December 2019.Delay between test_((-1))and test_((0))was>1year and test_((-1))result was negative(<150 ngHb/mL).The severity of colorectal lesions diagnosed at test_((0))was described according to Fhb measured at test_((-1))[Fhb_((-1))].The relationship between the severity classified in seven ordinal categories and the predictive factors was analyzed in an ordered multivariate polytomous regression model.RESULTS The test_((0))positive rate was 4.0%,and the colonoscopy completion rate was 97.1%in 11594 patients who showed a positive test_((0)).The colonoscopy detection rate was 77.7%in those 11254 patients who underwent a colonoscopy.A total of 8748 colorectal lesions were detected(including 2182 low-risk-polyps,2400 high-riskpolyp,and 502 colorectal cancer).The colonoscopy detection rate varied significantly with Fhb_((-1))[0 ngHb/mL:75.6%,(0-50 ngHb/mL):77.3%,(50-100 ngHb/mL):88.7%,(100-150 ngHb/mL):90.3%;P=0.001].People with a Fhb_((-1))within(100-150 ngHb/mL)(P=0.001)were 2.6(2.2;3.0)times more likely to have a high severity level compared to those having a Fhb_((-1))value of zero.This risk was reduced by 20%in patients aged 55-59 compared to those aged<55[adjusted odds ratio:0.8(0.6;1.0)].CONCLUSION The study showed that higher Fhb_((-1))is correlated to an increased risk of severity of colorectal lesions.This risk of severity increased among first-time participants(age<55)and the elderly(≥70).To avoid the loss of chance in these age groups,the FIT positivity threshold should be reduced to 100 ngHb/mL.The other alternative would be to reduce the time between the two tests in these age groups from the current 2 years to 1 year.

Supply and quality of colonoscopy according to the characteristics of gastroenterologists in the French population-based colorectalcancer screening program

BACKGROUND Since its complete roll-out in 2009,the French colorectal cancer screening program(CRCSP)experienced 3 major constraints[use of a less efficient Guaiac-test(gFOBT),stopping the supply of Fecal-Immunochemical-Test kits(FIT),and suspension of the program due to the coronavirus disease 2019(COVID-19)]affecting its effectiveness.AIM To describe the impact of the constraints in terms of changes in the quality of screeningcolonoscopy(Quali-Colo).METHODS This retrospective cohort study included screening-colonoscopies performed by gastroenterologists between Jan-2010 and Dec-2020 in people aged 50-74 living in Ile-de-France(France).The changes in Quali-colo(Proportion of colonoscopies performed beyond 7 mo(Colo_7 mo),Frequency of serious adverse events(SAE)and Colonoscopy detection rate)were described in a cohort of Gastroenterologists who performed at least one colonoscopy over each of the four periods defined according to the chronology of the constraints[gFOBT:Normal progress of the CRCSP using gFOBT(2010-2014);FIT:Normal progress of the CRCSP using FIT(2015-2018);STOP-FIT:Year(2019)during which the CRCSP experienced the cessation of the supply of test kits;COVID:Program suspension due to the COVID-19 health crisis(2020)].The link between each dependent variable(Colo_7 mo;SAE occurrence,neoplasm detection rate)and the predictive factors was analyzed in a two-level multivariate hierarchical model.RESULTS The 533 gastroenterologists(cohort)achieved 21509 screening colonoscopies over gFOBT period,38352 over FIT,7342 over STOP-FIT and 7995 over COVID period.The frequency of SAE did not change between periods(gFOBT:0.3%;FIT:0.3%;STOP-FIT:0.3%;and COVID:0.2%;P=0.10).The risk of Colo_7 mo doubled between FIT[adjusted odds ratio(aOR):1.2(1.1;1.2)]and STOPFIT[aOR:2.4(2.1;2.6)];then,decreased by 40%between STOP-FIT and COVID[aOR:2.0(1.8;2.2)].Regardless of the period,this Colo_7 mo’s risk was twice as high for screening colonoscopy performed in a public hospital[aOR:2.1(1.3;3.6)]compared to screening-colonoscopy performed in a private clinic.The neoplasm detection,which increased by 60%between gFOBT and FIT[aOR:1.6(1.5;1.7)],decreased by 40%between FIT and COVID[aOR:1.1(1.0;1.3)].CONCLUSION The constraints likely affected the time-to-colonoscopy as well as the colonoscopy detection rate without impacting the SAE’s occurrence,highlighting the need for a respectable reference time-tocolonoscopy in CRCSP.