Fecal α1-antitrypsin detection of colorectal neoplasia

Abstract

Fecal alpha 1-antitrypsin measurement may be of value for the detection of colorectal neoplasia and is compared with the HemoQuant test in 119 subjects with either a screen-positive Hemoccult result (N = 78) or iron-deficiency anaemia (N = 41). Nineteen patients were found to have colorectal cancer, 35 had colorectal adenomatous polyps, 5 had inflammatory bowel disease, and 60 had no detected cause of occult blood loss. Of the cancer patients, 63% (12/19) were detected by fecal alpha 1-antitrypsin and 63% (12/19) by HemoQuant. Of the adenomas > 1 cm in diameter 33% (7/23) were detected by fecal alpha 1-antitrypsin and 26% (6/23) by HemoQuant. There was a poor correlation between fecal alpha 1-antitrypsin and HemoQuant results for colorectal cancers (r = 0.37, P > 0.05), and combining the tests, the sensitivity for colorectal cancer was increased to 84% (16/19). Fecal protein loss, as measured using alpha 1-antitrypsin, appears to involve largely different mechanisms from that of blood loss from colorectal cancers.

Conflicts between Clinical and Public Health Viewpoints: Colorectal Screening

“…There have been efforts to make the immunochemical tests more sensitive by means of applying a second marker, such as lactoferrin [40], and alfa-1-antitripsin [41]. To date, most experiences have accumulated with the addition of albumin to haemoglobin as a marker of blood proteins [42,43].…”

“…Cancer detection test should be offered to patients who decline colonoscopy or another cancer prevention test. The preferred cancer detection test is annual FIT for blood [41,54]. However, colonoscopy is the gold standard for colorectal screening and the most common method.…”

Molecular stool screening for colorectal cancer

“…It has the advantage over other protein markers as it is often stable in stool. The sensitivity of α1‐antitrypsin‐based methods in detecting colorectal cancer is 63 per cent, but only 33 per cent for adenomas larger than 1 cm29.…”

Prospective Evaluation of Fecal Calprotectin As A Screening Biomarker for Colorectal Neoplasia

“…Three large randomized trials have shown that regularly testing asymptomatic persons for fecal occult blood may be associated with reduced colorectal cancer mortality rates (2)(3)(4)). Yet, fecal occult blood screening fails to detect a large percentage of clinically relevant colorectal neoplasms, particularly large adenomas (5)(6)(7)(8)(9).…”