Sialosyl-Tn antigen: initial report of a new marker of malignant progression in long-standing ulcerative colitis.
OBJECTIVE
Expression of the mucin-associated carbohydrate antigen sialosyl-Tn (STn) correlates with malignant transformation in sporadic colonic neoplasms. The aim of this study was to analyze STn antigen expression in patients with long-standing ulcerative colitis (UC).


METHODS
STn antigen was assessed by immunohistochemistry in archival tissues. Study A was a retrospective chronological case-control study. Serial surveillance colonoscopic biopsy specimens without inflammation or dysplasia were analyzed in 7 patients who developed colon cancer and in 8 controls who did not develop colon cancer. Study B analyzed the anatomic distribution of STn expression in 17 cancer-bearing (case) and 6 cancer-free (control) colectomy specimens from patients with UC. In some colectomy specimens, STn was compared with aneuploidy, which was determined by flow cytometry.


RESULTS
In study A, among the 7 patients with UC who developed cancer, 6 patients (86%) expressed STn in at least one prior nondysplastic surveillance biopsy specimen from the same site. Only 3 of 8 control patients (38%) expressed STn. In study B, STn was expressed in 40 of 82 specimens (49%) from cancer-bearing colons but only 8 of 62 specimens (13%) from cancer-free colons. STn was expressed in most aneuploid areas but was also found in diploid, nondysplastic mucosa.


CONCLUSIONS
STn antigen seems to be a promising marker of cancer risk in patients with UC.
Itzkowitz
S H
SH
Gastrointestinal Research Laboratory, Mount Sinai School of Medicine, New York, New York, USA.
Marshall
A
A
Kornbluth
A
A
Harpaz
N
N
McHugh
J B
JB
Ahnen
D
D
Sachar
D B
DB
D000782:Aneuploidy; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D016022:Case-Control Studies; D002471:Cell Transformation, Neoplastic / Q000276:immunology; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology; D003110:Colonic Neoplasms / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology / Q000473:pathology; D008137:Longitudinal Studies; D012189:Retrospective Studies
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C055491:sialosyl-Tn antigen