Enteric alpha-1-antitrypsin loss and comparison with Okokit II and Haemoccult for the detection of colorectal cancer.
Faecal samples from patients with symptomatic colorectal cancer (n = 19) and from control subjects (n = 54) were analysed for alpha-1-antitrypsin (A1AT) and compared with Haemoccult and Okokit II. A1AT was also measured in paired samples of normal colonic mucosa and cancer tissue (n = 16) and in media from four human colorectal cell lines (COLO 320 DM, SW620, HT29, LS 174T). Faecal A1AT concentrations were greater than controls (P < 0.0001) and detected 12 (63%) patients with cancer compared to 10 (53%) by Okokit II and 7 (37%) by Haemoccult (P > 0.05). A1AT concentrations from colonic mucosa (median, range: 0.46, 0.17-0.79 mg/g wet wt) were greater (P = 0.01) than cancer tissue (0.29, 0.13-0.74 mg/g wt wt). Adjusting for albumin, A1AT concentrations from mucosa (12.0, 3.8-32.2 mg/g albumin) remained greater (P = 0.003) than for cancer tissue (5.9, 2.4-21.4 mg/g albumin). A1AT was not detected in any of the cell-line media. The most likely mechanisms for increased faecal A1AT concentrations, apart from increased blood loss, are increased cell turnover or leakage from epithelial tight junctions. The use of faecal A1AT measurement for the detection of colorectal cancer deserves further assessment.
Department of Gastroenterology, Birmingham Heartlands Hospital, UK.
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Moran
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Hendrickse
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Jones
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Neoptolemos
D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000175:diagnosis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D014407:Tumor Cells, Cultured; D000515:alpha 1-Antitrypsin / Q000032:analysis*
D000515:alpha 1-Antitrypsin