Els Wieten

Effects of Increasing Screening Age and Fecal Hemoglobin Cutoff Concentrations in a Colorectal Cancer Screening Program.

BACKGROUND & AIMS Several countries have implemented programs to screen for colorectal cancer (CRC) by using the fecal immunochemical test (FIT). These programs vary considerably in age of the population screened and the cutoff concentration of fecal hemoglobin (Hb) used to identify candidates for further evaluation; these variations are usually based on a countrys colonoscopy resources. We calculated how increasing the Hb cutoff concentration and screening age affects colonoscopy yield, missed lesions, and demand. METHODS We collected data from 10,008 average-risk individuals in The Netherlands, 50-74 years old, who were invited for an FIT in the first round of a population-based CRC screening program from November 2006 through December 2008. Fecal samples were collected, and levels of Hb were measured by using the OC-sensor Micro analyzer; concentrations ≥10 μg Hb/g feces were considered positive. Subjects with a positive FIT were scheduled for colonoscopy within 4 weeks. Logistic regression analysis was performed to evaluate the association between age and detection of advanced neoplasia. RESULTS In total, 5986 individuals (62%) participated in the study; 503 (8.4%) had a positive test result. Attendance, positive test results, detection of advanced neoplasia, and the FITs positive predictive value all increased significantly with age (P < .001). Detection of advanced neoplasia ranged from 1.3% in the youngest age group to 6.2% in the oldest group; the positive predictive value of the FIT was 26% in the youngest group and 47% in the oldest group. Increasing the starting age of invitees from 50-74 years to 55-74 years reduced the proportion of subjects who underwent colonoscopy evaluation by 14% and resulted in 9% more subjects with advanced neoplasia being missed. Increasing the cutoff concentration from 10 to 15 μg Hb/g feces reduced the proportion of subjects who underwent colonoscopy evaluation by 11% and resulted in 6% of advanced neoplasia being missed. CONCLUSIONS In an analysis of an average-risk screening population in The Netherlands, we found that detection of advanced neoplasia by FIT increases significantly with age and fecal Hb cutoff concentration. Increasing the cutoff concentration or screening age reduces the numbers of patients who undergo colonoscopy evaluation in FIT-based CRC screening programs. Our findings provide insight in these effects per age category and cutoff concentration and the consequences in terms of missed lesions.

Fecal immunochemical test-based colorectal cancer screening: The gender dilemma

Background Despite differences between men and women in incidence of colorectal cancer (CRC) and its precursors, screening programs consistently use the same strategy for both genders. Objective The objective of this article is to illustrate the effects of gender-tailored screening, including the effects on miss rates of advanced neoplasia (AN). Methods Participants (age 50–75 years) in a colonoscopy screening program were asked to complete a fecal immunochemical test (FIT) before colonoscopy. Positivity rates, sensitivity and specificity for detection of AN at multiple cut-offs were determined. Absolute numbers of detected and missed AN per 1000 screenees were calculated. Results In total 1,256 individuals underwent FIT and colonoscopy, 51% male (median age 61 years; IQR 56–66) and 49% female (median age 60 years; IQR 55–65). At all cut-offs men had higher positivity rates than women, ranging from 3.8% to 10.8% versus 3.2% to 4.8%. Sensitivity for AN was higher in men than women; 40%–25% and 35%–22%, respectively. More AN were found and missed in absolute numbers in men at all cut-offs. Conclusion More AN were both detected and missed in men compared to women at all cut-offs. Gender-tailored cut-offs could either level sensitivity in men and women (i.e., lower cut-off in women) or level the amount of missed lesions (i.e., lower cut-off in men).

Accrediting for screening-related colonoscopy services: What is required of the endoscopist and of the endoscopy service?

Colorectal cancer (CRC) screening is widely implemented to reduce CRC incidence and related mortality. The impact of screening as well as the balance between screening burden and benefits strongly depends on the quality of colonoscopy. Besides quality, safety of the endoscopic procedure and patient satisfaction are important outcome parameters for a screening program. Therefore the requirements for both CRC screening endoscopy services and endoscopists focus on technical aspects, patient safety, and patient experience. Stringent quality assurance by means of routine monitoring of quality indicators for the performance of endoscopists and endoscopy units is recommended. This allows setting minimum standards, targeted interventions, and enhancement of the overall quality of population screening. This reviews deals with guidelines and quality standards for colorectal cancer screening, with focus on both endoscopist and endoscopy services.

Incidence of faecal occult blood test interval cancers in population-based colorectal cancer screening: a systematic review and meta-analysis

Objective Faecal immunochemical tests (FITs) are replacing guaiac faecal occult blood tests (gFOBTs) for colorectal cancer (CRC) screening. Incidence of interval colorectal cancer (iCRC) following a negative stool test result is not yet known. We aimed to compare incidence of iCRC following a negative FIT or gFOBT. Design We searched Ovid Medline, Embase, Cochrane Library, Science Citation Index, PubMed and Google Scholar from inception to 12 December 2017 for citations related to CRC screening based on stool tests. We included studies on FIT or gFOBT iCRC in average-risk screening populations. Main outcome was pooled incidence rate of iCRCs per 100 000 person-years (p-y). Pooled incidence rates were obtained by fitting random-effect Poisson regression models. Results We identified 7 426 records and included 29 studies. Meta-analyses comprised data of 6 987 825 subjects with a negative test result, in whom 11 932 screen-detected CRCs and 5 548 gFOBT or FIT iCRCs were documented. Median faecal haemoglobin (Hb) positivity cut-off used was 20 (range 10–200) µg Hb/g faeces in the 17 studies that provided FIT results. Pooled incidence rates of iCRC following FIT and gFOBT were 20 (95% CI 14 to 29; I2=99%) and 34 (95% CI 20 to 57; I2=99%) per 100 000 p-y, respectively. Pooled incidence rate ratio of FIT versus gFOBT iCRC was 0.58 (95% CI 0.32 to 1.07; I2=99%) and 0.36 (95% CI 0.17 to 0.75; I2=10%) in sensitivity analysis. For every FIT iCRC, 2.6 screen-detected CRCs were found (ratio 1:2.6); for gFOBT, the ratio between iCRC and screen-detected CRC was 1:1.2. Age below 60 years and the third screening round were significantly associated with a lower iCRC rate. Conclusion A negative gFOBT result is associated with a higher iCRC incidence than a negative FIT. This supports the use of FIT over gFOBT as CRC screening tool.

Optimizing Fecal Immunochemical Testing for Colorectal Cancer Screening

Colorectal cancer (CRC) screening aims to detect CRC and its precursors in an early phase, thereby reducing disease burden. This field is evolving rapidly, with an emphasis on population coverage, quality assurance, new screening methods, and individualized screening. There are various screening modalities available, each with their advantages and disadvantages. Guaiac fecal occult blood test (gFOBT) and sigmoidoscopy are the only strategies supported by evidence from prospective randomized controlled trials with CRC-related mortality as the end point. Fecal immunochemical testing (FIT) has been introduced as an alternative to gFOBT. FIT is easier to use, leads to higher population participation, and has higher accuracy for advanced neoplasia and CRC than gFOBT. FIT thus is expected to outperform gFOBT screening significantly in reducing CRC incidence and mortality. Consequently, most national screening programs in Europe and Asia-Pacific use FIT as the primary method for population-based screening. [...]