Expression of tumor-associated carbohydrate antigens correlates with hepatic metastasis of pancreatic cancer: clinical and experimental studies.

BACKGROUND/AIMS: This study was designed to detect an useful indicator to prognose postoperative hepatic metastases of pancreatic cancer.

MATERIALS AND METHODS

We analyzed clinical and histological data in thirty patients.

RESULTS

Of the ten items analyzed, only preoperative serum CA 19-9 level was indicative of postoperative hepatic metastases. When the patients were classified into two groups in regard to the CA 19-9 level making a boundary at 50 U/ml, the group of CA 19-9 level equal to, or over, 50 U/ml possessed a significantly higher frequency of the hepatic metastases. With a design based on these clinical results, we experimentally studied a correlation between expression of three carbohydrate antigens (CA 19-9, DUPAN-2 and Span-1) and incidence of blood-borne hepatic metastases in nude mice by using six human pancreatic, cancer cell lines. These antigens were immunocytochemically detectable in four cell lines (SUIT-2, AsPC-1, HPAF and Capan-2) and were undetectable in two cell lines (MIA PaCa-2 and BxPC-3). All of the former cell lines formed metastatic lesions in the liver. In contrast, the latter two did not cause hepatic metastases at all. Moreover, these antigens were expressed more intensely in the metastatic foci than in the primary transplanted tumor lesion in the spleen.

CONCLUSION

There is a positive correlation between expression of the carbohydrate antigens and metastatic potential of pancreatic cancer.