Expression of highly polysialylated neural cell adhesion molecule in pancreatic cancer neural invasive lesion

Neurotropism of pancreatic cancer is one of the hypotheses explaining neura l invasion, which is one of the characteristics of pancreatic cancer. In th ese studies, we immunohistochemically examined neural cell adhesion molecul es (NCAM), hemophilic adhesion molecules expressed on the nerve cells, as a factor of neurotropism, in 15 pancreatic cancer operatively obtained, espe cially in neural invasive lesions. We also investigated the role of polysia lic acid (PSA), which is attached to NCAM and related to the malignant pote ntial of cancers. NCAM was detected in 66.7% of pancreatic cancers, and in all 9 cases with massive perineural invasion. In neural invasive lesions, h owever, there were perineurium and endoneurium, which do not express NCAM, between the cancer and nerve cells. PSA was also detected in the pancreatic cancers expressing NCAM. Moreover, PSA expression was stronger in the peri neural invasive lesions than in the main tumor and was related to the cance r cell proliferation investigated by Ki-67 staining. It is unlikely therefo re, that NCAM plays an important role in neurotropism. However, the NCAM ex pressed on the pancreatic cancer was attached to PSA, which itself plays an important role in the malignant potential of this disease. (C) 1999 Elsevi er Science Ireland Ltd. All rights reserved.