Prognostic role of serum sialyl Lewisx (CD15s) in colorectal cancer.
OBJECTIVE
Sialyl Lewis(x) (sLe(x)) is one ligand for E selectin (CD62E), a glycoprotein that is expressed on activated endothelial cells. Adhesion mediated by endothelial E selectin and sLe(x) expressed on human tumor cells could be relevant for the development of metastases. The aim of this study was to investigate whether or not a correlation exists between pre-operative levels of ganglioside serum sLe(x) and disease-free interval and survival in colorectal cancer patients.


METHODS
Thirty Duke's B and 52 Duke's C patients undergoing resection for colorectal cancer were studied. The median follow-up time was 34.8 months. A pool of 57 sera from normal subjects was used as an Internal Normal Standard (INS). sLe(x) analyses were performed by a thin layer chromatography (TLC) immunostaining technique. Results were expressed as the ratio (R) between bands of INS and bands from each neoplastic serum.


RESULTS
The median R value was 0.80 in normal subjects, 0.70 in Duke's B patients and 1.0 in Duke's C patients. No significant differences were detected between sLe(x) concentrations in sera from normal and neoplastic subjects (p = 0.1). Using an arbitrary cutoff of R = 0.9, the mean disease-free interval in the whole series was 47.4 months for R <0.9 and 126.0 months for R > or = 0.9 (p = 0.04). The survival time was 76.8 months for patients with R values <0.9 and 156.3 months for patients with R values > or =0.9 (p = 0.1).


CONCLUSIONS
High serum levels of ganglioside sLe(x) significantly correlate with a favorable prognosis and with a lower occurrence of metastases. It is conceivable that soluble sLe(x) may compete with membrane-bound sLe(x) in the course of interactions between activated endothelium and tumor cells that have reached the circulation.
Paganuzzi
Michela
M
Clinical Pathology Laboratory, Cancer Research Institute, University of Genoa, Genoa, Italy. michela.pagnuzzi@istge.it
Bobbio
Barbara
B
Marroni
Paola
P
Filiberti
Rosa
R
Secco
Giovanni Battista
GB
Grossi
Carlo Enrico
CE
D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D002855:Chromatography, Thin Layer; D015179:Colorectal Neoplasms / Q000097:blood / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007558:Italy; D016256:Lewis X Antigen / Q000097:blood*; D008297:Male; D009362:Neoplasm Metastasis; D009844:Oligosaccharides / Q000097:blood*; D011379:Prognosis; D000080506:Sialyl Lewis X Antigen; D016019:Survival Analysis
D014408:Biomarkers, Tumor; D016256:Lewis X Antigen; D009844:Oligosaccharides; D000080506:Sialyl Lewis X Antigen