ERas activation and GKN2 reduction in gastric cancer has raised some notices in recent years, while nuclear beta-catenin positivity is considered as a tumoral marker. In this study, we compared immunohistochemistry of beta-catenin, GKN2 and ERas on tumoral and non-tumoral mucosae of 50 gastric carcinomas and 13 gastric samples of cancer-free patients. Nuclear positivity of beta-catenin was strong in 31 non-tumoral mucosae (62%) and 29 tumoral mucosae (58%). It was absent in samples of cancer-free patients. There was a correlation between non-tumoral and tumoral zones for nuclear beta-catenin positivity (P=0.013). ERas was positive in 35 non-tumoral tissues (70%) and 31 tumoral tissues (62%) but negatvie in samples of cancer-free patients. It was weak and spotty in non-tumoral mucosae but strong and diffuse in tumors. Positivity of ERas was age-related (P=0.028). However it had background staining effect. GKN2 was expressed in 33 non-tumoral mucosae (66%) and 35 tumoral mucosae (70%). Though GKN2 staining was moderate to strong in non-tumoral tissues and was comparatively weaker in tumors, their difference was minimal and difficult to discern.
Conclusions: Beta-catenin nuclear location could be considered as a paraneoplastic pattern which is considerably tumor-related. ERas may be a potential biomarker for gastric cancer, but advanced studies are wanted. GKN2 reduction is indiscernible by immunostaining.
Keywords: ERas; Stomach neoplasm; beta Catenin; gastric mucosa; gastrokine 2.