[The prognostic factors of pancreatic cancer--adhesion molecule CD44]

The prognosis for pancreatic cancer is extremely poor, because there are usually invasion of surrounding tissues and metastases to lymph nodes, liver or peritoneum at the time of diagnosis. Many studies from the molecular-biological stand point have demonstrated this poor prognosis. However, the mechanisms underlying these invasive and metastatic capabilities have not yet been clarified. We reviewed several reports for prognostic factors of pancreatic cancer in molecular-biological examinations, and introduced our recent study on the adhesion molecule CD44. The CD44 variant 6 (v6) molecule has been noted as a marker for tumor metastasis and prognosis in several tumors. We examined whether or not v6 is a useful marker for evaluating the prognosis of pancreatic cancer patients. In addition, we attempted to assess the clinicopathological implications for pancreatic cancer of the variant 2 (v2) isoform using a recently developed monoclonal antibody against a v2 epitope. The expression of CD44 v6 and v2 was observed only in tumor cells, if at all. The expression of CD44 v6 and v2 was correlated with decreased overall survival. A significant correlation was obtained between CD44 v2 and vessel invasion. These results suggest that CD44 v2 and CD44 v6 may be useful markers of a poor prognosis.