Role of Notch signaling pathway in gastric cancer: a meta-analysis of the literature.

AIM: To perform a meta-analysis to quantitatively summarize the evidence for the association between the Notch signaling pathway and gastric cancer (GC).

METHODS: An electronic search of the MEDLINE, EMBASE and Chinese National Knowledge Infrastructure, which contain articles published from 1966 onwards, was conducted to select studies for this meta-analysis.

RESULTS: Fifteen studies with a total of 1547 gastric cancer cases and 450 controls were included in this meta-analysis. Overall, the expression of Notch1, Notch2, Delta-like 4 and Hes1 was significantly higher in tumor tissues of GC compared to normal tissues. Specifically, stratified analyses showed that significantly increased expression of Notch1 was associated with non-cardia location, > 5 cm size, diffuse type, positive lymphovascular invasion and distal metastasis. Statistically significant higher expression of Notch3 was found in diffuse type GC. Jagged1 was also significantly over-expressed in diffuse type and poor differentiation type of GC. DLL4 was significantly over-expressed in advanced T stage, N stage and TNM stage in GC patients. However, the stratified analysis showed that there was no statistically significant difference in Hes1 expression between different subgroups. Sporadic reports showed that Notch1 and Jagged1 were independent poor prognostic predictors in GC.

CONCLUSION: The Notch signaling pathway plays an important role in tumor progression of gastric cancer.