Fig. 1

Stromal fibroblast activation protein-α (FAP) expression in resected pancreatic ductal adenocarcinoma (PDAC), and relationship between intensity of FAP expression and cumulative survival in patients with PDAC. A The expression of FAP was found predominantly in stromal cells and slightly in cancer cells (a-c, x200 field magnification). Stromal fibroblast FAP expression was graded by the number of positive cells per 1000 stromal fibroblasts for three randomly selected views (weak < 350 [d], 350 ≤ moderate < 650 [e], and 650 ≤ strong [f]), but negative in chronic pancreatitis (g) and noncancerous pancreatic tissues that were resected due to bile duct cancer (h) and duodenal papillary cancer (i) (d-i, x400 field magnification). B Cumulative survival curves for PDAC patients with negative or weak FAP expression and those with moderate or strong FAP expression. The solid line and broken lines indicate patients with negative or weak FAP expression and those with moderate or strong FAP expression, respectively. Log-rank test P = 0.006