Since 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 variants was 
evaluated immunohistochemically in paraffin-embedded pancreatic cancer tissues 
from 42 patients who were confirmed surgically and histologically to have 
received curative resection. An indirect immunoperoxidase method was used with 
monoclonal antibodies against epitopes of the standard (CD44s) portion, v6 and 
v2. Protein expression data were evaluated statistically for any correlations 
with the length of survival or with histological parameters. The expression of 
CD44v6 and v2 was observed only in tumor cells, if at all. On the other hand, 
expression of total CD44 (including CD44v, as well as CD44s) was observed in 
both tumors and adjacent normal sites. Tumor tissue from 21 (50%) and 16 (38%) 
patients showed positive immunoreactivity with mAb 2F10 (anti-CD44v6) and mAb 
M23.6.1 (anti-CD44v2), respectively. The expression of CD44v6 and v2 was 
correlated with decreased overall survival (P = 0.0160 and P = 0.0125, 
respectively). A significant correlation was obtained between CD44v2 peptide 
expression and vessel invasion (P = 0.026). These results suggest that CD44v2 
and CD44v6 may be useful markers for poor prognosis in curatively resected 
primary pancreatic cancer.