Sialoglycoconjugate expression in primary colorectal cancer and metastatic lymph node tissues.

OBJECTIVE

Aberrant cell surface glycosylation, and especially excessive sialylation, is thought to have great importance in tumor malignancy. To investigate the clinicopathological significance of sialylation in colorectal cancer, we performed histochemical analyses using sialic acid-binding lectins.

METHODS

Primary colorectal cancer and lymph node tissues obtained from 80 cases were subjected to lectin-immunohistochemical staining using Maackia amurensis leukoagglutinin (MAL) and Sambucus nigra agglutinin (SNA). The relationship between the staining characteristics and the various clinicopathological parameters was statistically analyzed.

RESULTS

In primary cancer tissues, a high level of SNA staining was significantly related to worse prognosis and some pathological characteristics such as lymph node metastasis, whereas a high level of MAL staining was related to worse prognosis. In metastatic lymph node tissues, positive staining was frequently found for MAL and SNA, which wasremarkable in cases categorized as N2 metastasis. Furthermore, cases with MAL-positive staining in metastatic lymph node tissues evidently indicated worse prognosis than those with MAL-negative staining.

CONCLUSIONS

Aberrant expression of SNA-positive sialoglycoconjugates in primary colorectal cancer tissues is important in terms of unfavorable pathological characteristics of the cancer. In addition, aberrant expression of MAL-positive sialoglycoconjugates in metastatic lymph node tissues might be related to worse prognosis.