Differences in release mechanisms and distributions for sialyl Le(a) and sialyl Le(x) antigens in colorectal cancer.
BACKGROUND
To investigate colorectal cancer-related carbohydrate antigen release and distribution, we evaluated serum levels of sialyl Le(a) (CA19-9) and sialyl Le(x) antigen (SLX) in blood samples obtained from both a peripheral vein and a tumor's draining vein.


METHODS
Blood samples were obtained during surgery from 126 patients. Based on these samples, patients were placed into a high-antigen group, with a concentration above a selected cutoff value, or into a low-antigen group, with a tumor marker concentration below that same value. The blood samples obtained from peripheral veins were designated by the "p" prefix, and samples from drainage veins were designated by the "d."


RESULTS
Serum d-SLX levels were significantly higher than p-SLX levels (P < .0001), although there was no difference between those of d-CA19-9 and p-CA19-9. Only 1 (3.6%) of 28 patients in the high d-CA19-9 group had a low p-CA19-9. In contrast, 6 (33.3%) of 18 patients in the high d-SLX group had low p-SLX levels (P = .0103). Correlations between pathological variables and either p-CA19-9 levels or d-CA19-9 levels were similar. However, both distant metastasis and venous invasion did prove to be independent variables related to d-SLX levels, as shown by logistic regression analysis.


CONCLUSIONS
SLX may drain predominantly via the draining veins of colorectal tumors into portal circulation, whereas CA19-9 may drain via another route.
Nakagoe
T
T
First Department of Surgery, Nagasaki University School of Medicine, Japan. nakagoe@net.nagasaki-u.ac.jp
Sawai
T
T
Tsuji
T
T
Jibiki
M
M
Ohbatake
M
M
Nanashima
A
A
Yamaguchi
H
H
Yasutake
T
T
Ayabe
H
H
Tagawa
Y
Y
D000368:Aged; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D015179:Colorectal Neoplasms / Q000276:immunology*; D005260:Female; D005732:Gangliosides / Q000097:blood*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009844:Oligosaccharides / Q000097:blood*; D000080506:Sialyl Lewis X Antigen
D015295:Antigens, Tumor-Associated, Carbohydrate; D018395:CA-19-9 Antigen; D005732:Gangliosides; D009844:Oligosaccharides; D000080506:Sialyl Lewis X Antigen; C064564:sialyl Le(a) ganglioside