Monoclonal antibody Adnab-9 defines a preneoplastic marker in epithelium at risk for adenocarcinoma of the small intestine.
Unlike colorectal cancer, risk markers for adenocarcinoma of the small intestine (ASI) have not been identified. Because the demographic and pathological features of both of these diseases are similar, immunohistochemistry was performed using monoclonal antibodies for three colonic premalignant markers, Adnab-9 (recognizes a colonic adenoma epitope), CaCo3/61, and FBB2/29 (small intestine proteoglycans expressed ectopically in colonic neoplasms), in normal and neoplastic small intestinal epithelium, and the results were compared with normal controls. Adnab-9 was also examined in 20 familial adenomatous polyposis (FAP) patients, a population known to be at an increased risk for ASI. Immunohistochemistry in normal and neoplastic tissue (adenoma, adenocarcinoma) from 18 patients with primary adenocarcinoma of the small intestine was compared with normal small intestine from 10 nonneoplastic controls. Four of 10 (40%) cases of normal small intestinal epithelium from controls were mildly positive in less than 10% of crypts, versus strong staining (>50% of crypts) in 16 of 18 (89%) patients with adenocarcinoma, and in 17 of 20 (85%) patients with FAP (P<.05). Adnab-9 predominantly stained Paneth cells as well as rare crypt and basal villous goblet cells. Adenomatous epithelium from the adenocarcinoma cases and adenomas from the FAP patients showed staining of Adnab-9 in 63% and 78% of cases, respectively. Only 17% of adenocarcinomas were positive for Adnab-9. In contrast, neither CaCo3/61 nor FBB2/29 showed any significant differences in the degree of staining in normal small intestinal epithelium in patients with adenocarcinoma compared with controls. Enhanced Adnab-9 staining in normal small intestinal epithelium from patients who harbor adenocarcinoma, and in FAP patients, supports its role as a risk marker of small intestinal neoplasia.
Tobi
M
M
Department of Medicine, John D. Dingell Veterans Affairs Medical Center, and Wayne State University Medical School, Detroit, MI, USA.
Kaila
V
V
Hassan
N
N
Gallinger
S
S
Fligiel
S
S
Hatfield
J
J
Gesell
M
M
Sakr
W
W
Luk
G
G
Odze
R D
RD
D000230:Adenocarcinoma / Q000276:immunology / Q000378:metabolism*; D011125:Adenomatous Polyposis Coli / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D007414:Intestinal Neoplasms / Q000276:immunology / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000378:metabolism*; D012307:Risk Factors
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor