EMT-related genes are unlikely to be involved in extracapsular growth of lymph node metastases in gastric cancer

Abstract Background In gastric cancer (GC), extracapsular growth (ECG) pattern of lymph node metastases is associated with decreased overall survival rates compared to intracapsular lymph node metastases (ICG). Epithelial-to-mesenchymal transition (EMT) plays a pivotal role in hematogenous metastatic spread. Aim of the present study was to analyze if EMT related genes are involved in the growth pattern of lymph node metastases in GC. Methods Out of our prospective database with 529 patients who underwent surgical resection for GC between 2002 and 2014 forty lymph node positive patients were identified (20 ECG, 20 ICG). The expression of 84 EMT-associated genes were analyzed by RT2 Profiler PCR Array (n=20). Results were validated by Real-Time PCR (n=20). Results GC with ECG showed differently expressed EMT related genes. GC leading to ECG showed an upregulation of three and downregulation of eleven genes. Those differences, however, could not be confirmed in PCR analysis. Conclusions This study demonstrates that EMT related genes are not responsible for the different growth patterns of lymph node metastases in GC. Further studies are required to evaluate the underlying mechanisms of ECG in GC as it might provide a potential therapeutic target for this subgroup of more aggressive tumors in the future.