Significant decrease in interval colorectal cancer incidence after implementing immunochemical testing in a multiple-round guaiac-based screening programme.

BACKGROUND AND AIMS: We aimed to evaluate the effects of switching to faecal immunochemical testing (FIT) on the cumulative 2-year incidence rate of interval cancers, interval cancer rate and test sensitivity within a mature population-based colorectal cancer screening programme consisting of six rounds of biennial guaiac faecal occult blood testing (gFOBT). METHODS: The FIT results were compared with those of gFOBT used in each of the previous two rounds. For the three rounds analysed, 279,041 tests were performed by 156,186 individuals. Logistic regression analysis was used to determine interval cancer risk factors (Poisson regression) and to compare the sensitivity of FIT to gFOBT. RESULTS: There were 612 cases of screen-detected cancers and 209 cases of interval cancers. The sex- and age-adjusted cumulative 2-year incidence rates of interval cancers were 55.7 (95% CI, 45.3-68.5), 42.4 (95% CI, 32.6-55.2) and 15.8 (95% CI, 10.9-22.8) per 100,000 person-years after the last two rounds of gFOBT and FIT, respectively. The FIT/gFOBT incidence rate ratio was 0.38 [95% CI, 0.27-0.54] (P < 0.001). Sex- and age-adjusted sensitivity was significantly higher with FIT than with gFOBT (OR = 6.70 [95% CI, 4.48-10.01], P < 0.0001). CONCLUSIONS: This population-based study revealed a dramatic decrease in the cumulative incidence rates of interval cancers after switching from gFOBT to FIT. These data provide an additional incentive for countries still using gFOBT to switch to FIT.

Benefits of switching from guaiac-based faecal occult blood to faecal immunochemical testing: experience from the Wallonia-Brussels colorectal cancer screening programme.

BACKGROUND: Faecal immunochemical tests (FITs) have replaced guaiac-based faecal occult blood test (gFOBTs) in several colorectal cancer (CRC) screening programmes. We aimed to evaluate the benefits of this transition based on the Wallonia-Brussels-organised CRC screening programme. METHODS: A total of 1,569,868 individuals aged 50-74 years, who were invited to screening during 2009-2017, were studied by linking their screening records with insurance, pathology and cancer data in the Belgian Cancer Registry. We compared neoplasm detection rates and positive predictive values (PPVs) of gFOBT and FIT at 15 µg haemoglobin per gram cut-off in screen-naive individuals. We furthermore examined the incidence rates of interval cancer in gFOBT- and FIT-based screening programme. RESULTS: Advanced neoplasms were detected less frequently by gFOBT (0.8%) than by FIT (1.3%), with a difference of 0.5% (P < 0.01). PPVs were lower for gFOBT (15.1%) than for FIT (21.7%) for advanced neoplasms (difference 6.6%, P < 0.01). Compared to participants with negative gFOBT, those with negative FIT were 77% less likely to develop interval cancer (incidence rate ratio 0.23, 95% confidence interval 0.16-0.33). CONCLUSION: Our study demonstrated that in an organised CRC screening programme, replacing gFOBT with FIT improved neoplasm detection rate and substantially reduced interval cancer incidence.

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.

Contribution of the OC Sensor® immunoassay in comparison to the Hemoccult II® guaiac-test in organized colorectal cancer screening.

Colorectal cancer (CRC) is a major cause of cancer-related death of worldwide with high incidence and mortality rate, accessible to a screening program in France, first with guaiac- based fecal occult blood test (g-FOBT) then with fecal immunochemical tests (FIT), since 2015, because of better accuracy. The aim of our study was to compare the characteristics of screen-detected lesions in two successive CRC screening campaigns, using two different tests (Hemoccult II® and OC Sensor®) in the department of Maine-et-Loire, and to precise the performance of these tests [participation rate, detection rates (DR), positive predictive value (PPV)]. Participants, invited by CAP SANTE 49, with polyps or cancer at the colonoscopy after a positive screening test between 01/01/2013 and 31/12/2016 were included. A guaiac-based fecal occult blood test (g-FOBT) was used from January 2013 to December 2014 and a FIT was used from June 2015 to December 2016). 2575 participants, 642 in g-FOBT group and 1933 in FIT group had lesions. Participation rate was not different between tests (p = 0.104), whereas DR and PPV were statistically higher in FIT for all lesions (2.61, 95% CI [2.50-2.70] vs 0.93, 95% CI [0.90-1.00], p < 0.0001 and 64.84, 95% CI [63.10-66.60], 50.00, 95% CI [47.30-52.70], p < 0.0001 respectively). FIT detects more precancerous lesions (adenomas, p < 0.001, and advanced adenomas, p < 0.001) than g-FOBT but g-FOBT detects more serrated polyps (p = 0.025). AAs were more in right colon in FIT than g-FOBT (p = 0.035). No different participation rate was detected between FIT and g-FOBT but DR and PPV of all lesions was higher with FIT.

Comparison of a New-generation Fecal Immunochemical Test (FIT) With Guaiac Fecal Occult Blood Test (gFOBT) in Detecting Colorectal Neoplasia Among Colonoscopy-referral Patients.

BACKGROUND/AIM: The aim of the present study was to compare fecal immunochemical tests (FITs) for colorectal cancer (CRC) screening with the traditional guaiac-based FOB tests (gFOBT). MATERIALS AND METHODS: A cohort of 368 colonoscopy-referral patients were evaluated by i) the new-generation FIT: ColonView quick test (CV; Biohit Oyj, Finland) and ii) a conventional gFOBT HemoccultSENSA (HS; Beckman Coulter, USA). Three fecal samples were requested for both assays, and all subjects underwent diagnostic colonoscopy with biopsy confirmation. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and area under curve (AUC) were calculated for both tests using three endpoints: adenoma (A), advanced adenoma (AA) and adenocarcinoma (AC). RESULTS: Colonoscopy and biopsies disclosed normal mucosa in 90/378 (24.5%) subjects, early A in 108/368 (29.3%) cases, AA in 48/368 (13.0%) and AC in 37/368 (10.1%), and non-neoplastic conditions in the remaining 85 (30.3%). For the AC endpoint, the CV (Hb/Hp) test had 94.6% SE and 65.1% SP (AUC=0.799), while the HS test had SE of 75.7% and SP of 84.3% (AUC=0.800). For the A endpoint, the difference between CV and HS was even more pronounced; SE of 44.2% and 19.2%, respectively (p<0.0001). Hb and Hb/Hp complex of the CV test showed equal performance for all endpoints. CONCLUSION: Sensitivity (94.6%) of the ColonView quick test for the most reproducible endpoint (invasive CRC) far exceeded the pooled sensitivity (79%) estimated in a recent meta-analysis for 8 common FIT brands. As shown in a previous study, ColonView quick test is superior in SE to HemoccultSENSA test, making CV a perfect FIT for organized CRC screening.

Detection of Colorectal Neoplasia in a Cohort Before and After the Change of Fecal Occult Blood Test in a French Colorectal Cancer Screening Program.

OBJECTIVE: To estimate the change in the participation rate and the change in neoplasia incidence before and after the change of the Fecal Occult Blood Test (FOBT) in the cohort included in the Colorectal Cancer Screening Program (CRCSP). METHODS: Cohort of 279,210 people, aged 50-74 years, invited at least once before 2009, to participate in a CRCSP campaign. The participation rate and the cumulative neoplasia incidence were described on 4 campaigns (≤2008, 2009-2010, 2011-2012 and 2013-2014) with a Guaiac FOBT (gFOBT) and a first campaign (2015-2016) with a Fecal Immunochemical Test (FIT). The cumulative incidence was estimated by the actuarial method and its confidence interval by the Greenwood method. RESULTS: The participation rate decreased from 32.7% (first gFOBT-campaign) to 24.4% (fourth gFOBT-campaign) then, made a significant bound in the FIT-campaign (28.4%; p < 0.001). 35.4% of the 965 high-risk-polyps screened in this cohort were detected in the FIT-campaign. CRC incidence gradually decreased from 0.4 to 0.1/1000 person-years from the first to the fourth gFOBT-campaign before reaching a bound to 0.4/1000 person-years in the FIT-campaign. CONCLUSION: Although it was still below the minimum European target (45%), the participation rate has increased between the last gFOBT-campaign and FIT-campaign, justifying the impact of promotional campaigns and the acceptance of the new test by people and GPs. A decline in the neoplasia incidence was observed between the initial and the fourth gFOBT-campaign. The change from gFOBT to FIT between the fourth and fifth campaigns, was associated with a significant increase in detection of neoplasia.

Lignans from guaiac resin decrease nitric oxide production in interleukin 1ß-treated hepatocytes.

Guaiac resin, extracted from the heartwood of Guaiacum officinale L. or G. sanctum L., is speculated to have anti-inflammatory effects. Lignans were purified from guaiac resin (also known as gum guaiacum) by monitoring the nitric oxide (NO) production in rat hepatocytes treated with an inflammatory cytokine interleukin-1ß (IL-1ß). Six lignans were purified from guaiac resin and identified as: dehydroguaiaretic acid (1), (+)-trans-1,2-dihydrodehydroguaiaretic acid (2), furoguaiaoxidin (3), meso-dihydroguaiaretic acid (4), furoguaiacin (i.e., α-guaiaconic acid) (5), and nectandrin B (6). To our knowledge, this is the first time that 1 has been isolated from guaiac resin as a non-derivative. Compounds 2 and 6 were first found in guaiac resin. Compound 3 was first isolated from a natural source as a non-derivative. Furthermore, 1-6 significantly suppressed NO production in IL-1ß-treated hepatocytes. Because anti-inflammatory compounds suppress NO production, this system is often used to measure the anti-inflammatory effects of Kampo drugs and herbal constituents. The NO-suppressing activity of the six lignans isolated in this study indicates that guaiac resin has anti-inflammatory effects and that these lignans may be responsible for the anti-inflammatory effects of guaiac resin.

Effect of rehydration on guaiac-based faecal occult blood testing in colorectal cancer screening.

Screening for colorectal cancer by means of unhydrated Hemoccult (HO) is in progress in the Province of Florence since 1982. In 1990 rehydrated HO was introduced in the town of Empoli. Five adjacent municipalities where screening had started in 1987 were selected for comparison. In both areas subjects aged 40-70 were invited by mail to undergo the screening protocol. HO-positive subjects were invited to undergo either pancolonoscopy or a combination of left colonoscopy and double contrast barium enema. HO-negative subjects were invited to repeat screening 2 years later. The positivity rate of HO was significantly higher (P < 0.001) for rehydrated (5%) as compared to unhydrated (3.1%) HO. The positive predictive values for cancer (unhydrated: 5.8%; rehydrated: 8.9%) and for adenomas (unhydrated: 26.7%; rehydrated: 25.5%) did not significantly differ. The detection rates of rehydrated HO were significantly higher as compared to unhydrated HO both for cancer (0.37% vs 0.15%; P < 0.05) and adenomas (1.06% vs 0.72%; P < 0.05%). In the present experience rehydration doesn't produce any decrease in the positive predictive value for cancer or adenomas and the increase in the positivity rate appears quite acceptable when considering the significant increase in the detection rates of cancer and adenomas. We conclude that rehydrated HO should be introduced as the standard test for screening in order to increase sensitivity for colorectal cancer and adenomas.