Sialosyl-Tn. A novel mucin antigen associated with prognosis in colorectal cancer patients.
Colon cancers typically produce mucin. However, it is not known whether tumor mucin plays a biological role in cancer cell behavior. To address this issue, the expression of a mucin-associated antigen, sialosyl-Tn, was examined by immunohistochemical study in 128 primary colorectal carcinoma specimens from 137 patients who underwent curative surgical resection. Antigen expression was correlated with disease-free and overall 5-year survival. Sialosyl-Tn antigen expression occurred in 112 (87.5%) tumors, and was independent of age, gender, tumor location, Dukes' stage, depth of invasion, degree of differentiation, and ploidy status. Survival at 5 years for patients with sialosyl-Tn-negative versus sialosyl-Tn-positive tumors was 100% versus 73% (P less than 0.05) and disease-free survival was 94% versus 73%, respectively (P = 0.12). Although more advanced Dukes' stage, deeper invasion, and aneuploidy were all associated with poorer overall 5-year survival, antigen-negative tumors within each of these groups had much better prognoses than antigen-positive tumors. Multivariate regression analysis revealed that tumor ploidy (P less than 0.001) and sialosyl-Tn expression (P less than 0.05) were the two variables of most importance for predicting both disease-free and overall survival. The authors conclude that sialosyl-Tn expression is an independent predictor of poor prognosis in colon cancer, and therefore suggest that qualitative mucin alterations may reflect important differences in the biological behavior of these neoplasms.
Itzkowitz
S H
SH
Gastrointestinal Research Laboratory, Veterans Administration Medical Center, San Francisco, California.
Bloom
E J
EJ
Kokal
W A
WA
Modin
G
G
Hakomori
S
S
Kim
Y S
YS
D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology*; D015295:Antigens, Tumor-Associated, Carbohydrate; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000276:immunology*; D011237:Predictive Value of Tests; D011379:Prognosis
D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D009077:Mucins; C055491:sialosyl-Tn antigen