Diffuse expression of hRFI is correlated with blood vessel invasion in gastric carcinoma

hRFI, which has a relatively high homology to XIAP, is preferentially expressed in esophageal and colorectal carcinomas, and is involved in the initial tumor formation in the colorectal adenoma-carcinoma sequence. Furthermore, its diffuse expression is associated with colorectal carcinogenesis. However, hRFI expression in gastric carcinomas has not been evaluated so far.

We performed immunohistochemical staining on 76 gastric carcinoma samples using the antibody to hRFI and also analyzed the correlation between the staining pattern of hRFI and the clinico-pathological characteristics.

All of the samples were stained focally (31 cases, 40.8%) or diffusely (45 cases, 59.2%) in the cancerous region. On the contrary, most of the normal gastric region showed no staining, except for a few cases that showed slight immunoreactivity in speckles. Furthermore, the proportion of blood vessel involvement was significantly higher in carcinomas with diffuse hRFI expression (28/45, 62.2%) than in carcinomas with focal expression (7/31, 22.6%) (P < 0.001). Liver metastasis was consistently observed in five cases (11.1%) in diffuse, but only one (3.3%) in focal type during the average follow up period of 5 years. However, the 3-year survival rate did not show significant difference between these different staining patterns of hRFI.

These results suggest that the detection of the expression pattern of hRFI in gastric carcinomas can be another useful predictor of liver recurrence, especially when combined with other factors.