A combination of nuclear β-catenin and atypical scores as useful diagnostic markers for borderline malignancy of gastric tumours

Abstract

Aims: Although recent advances in endoscopic technology, including submucosal dissection (ESD), contribute to significant improvement in detection and treatment for early gastric carcinomas (GCas), discrepant diagnosis between forceps biopsied and ESD sections sometimes occurs. Here, we focused on histological markers for accurate diagnosis of gastric tumours in forceps biopsied samples before ESD treatment. Methods and results: A total of 136 cases of gastric tumours, including 25 adenomas and 111 GCas, were investigated using a combination of forceps biopsied and ESD samples. Atypical scores based on both nuclear and branching parameters could distinguish between adenomas and GCas in both samples. The labelling indices (LIs) of nuclear β-catenin were significantly higher in GCas than adenomas, and positively correlated with atypical scores, as well as branching parameters. In addition, nuclear β-catenin immunoreactivity showing small cluster pattern was colocalized with immunoreactivity for aldehyde dehydrogenase 1 (ALDH1), known as a cancer stem cell (CSC) marker, which suggests the presence of some CSC population, and may be due to formation of dynamic tubular branching in GCas. Conclusions: A combination of nuclear β-catenin and atypical scores may be useful for differential diagnosis of borderline malignancy of gastric tumours.