Test Performance of Immunologic Fecal Occult Blood Testing and Sigmoidoscopy Compared with Primary Colonoscopy Screening for Colorectal Advanced Adenomas

Abstract

Given the current increase in colorectal cancer screening, information on performance of screening tests is needed, especially in groups with a presumed lower test performance. We compared test performance of immunologic fecal occult blood testing (FIT) and pseudosigmoidoscopy with colonoscopy for detection of advanced adenomas in an average risk screening population. In addition, we explored the influence of gender, age, and location on test performance. FIT was collected prior to colonoscopy with a 50 ng/mL cutoff point. FIT results and complete colonoscopy findings were available from 329 subjects (mean age: 54.6 AE 3.7 years, 58.4% women). Advanced adenomas were detected in 38 (11.6%) of 329 subjects. Sensitivity for advanced adenomas of FIT and sigmoidoscopy were 15.8% (95% CI: 6.0-31.3) and 73.7% (95% CI: 56.9-86.6), respectively. No sensitivity improvement was obtained using the combination of sigmoidoscopy and FIT. Mean fecal hemoglobin in FIT positives was significantly lower for participants with only proximal adenomas versus those with distal ones (P ¼ 0.008), for women versus men (P ¼ 0.023), and for younger (<55 years) versus older (!55 years) subjects (P ¼ 0.029). Sensitivities of FIT were 0.0% (95% CI: 0.0-30.9) in subjects with only proximal versus 21.4% (95% CI: 8.3-41.0) in those with distal nonadvanced adenomas; 5.3% (95% CI: 0.0-26.0) in women versus 26.3% (95% CI: 9.2-51.2) in men; 9.5% (95% CI: 1.2-30.4) in younger versus 23.5% (95% CI: 6.8-49.9) in older subjects. Sigmoidoscopy had a significantly higher sensitivity for advanced adenomas than FIT. A single FIT showed very low sensitivity, especially in subjects with only proximal nonadvanced adenomas, in women, and in younger subjects. This points to the existence of "low" FIT performance in subgroups and the need for more tailored screening strategies. Cancer Prev Res; 4(10); 1563-71. Ó2011 AACR.

Faecal haemoglobin concentration is related to severity of colorectal neoplasia

“…Moreover, at any cut-off f-Hb, the sensitivity and positive predictive value for significant neoplasia (cancer plus high-risk adenoma) is substantially higher and specificity and negative predictive value lower among men than women 9. More recently, it has been demonstrated that mean f-Hb in FIT-positive individuals is significantly lower in women compared with men and for younger compared with older participants 10. Few studies11–13 have demonstrated that f-Hb increases as disease becomes more serious, from the normal through low- and high-risk adenomatous polyps (LRA, defined as <3 or any <10 mm, HRA, defined as ≥3 or any ≥10 mm) to invasive cancer.…”

Potentiality of a triple microRNA classifier: miR-193a-3p, miR-23a and miR-338-5p for early detection of colorectal cancer

“…Fecal-based analyses such as occult blood, immunochemical and stool DNA tests are common noninvasive screening tests [9]. Nevertheless, they are confined by low sensitivity and specificity against detection of premalignant lesions [10,11]. Although stool DNA test utilizes molecular markers such as KRAS , APC and TP53 genes as detection targets, it is not favorably recommended by the US Preventive Service Task Force due to high cost, uncertainty of test performance and labor-intensive handling [12-14].…”

Strong subsite‐specific variation in detecting advanced adenomas by fecal immunochemical testing for hemoglobin

“…A number of studies have addressed site specific sensitivity of FITs, and most of them found somewhat lower sensitivity for proximal compared to distal neoplasms . Typically, however, no further distinction according to subsite within the proximal colon or distal colon and rectum was made.…”