Overexpression of YAP1 is correlated with progression, metastasis and poor prognosis in patients with gastric carcinoma.

YAP1 is overexpressed in numerous cancers, but its molecular mechanism in the carcinogenesis and clinic significance in tumor diagnosis and prognosis remains to be determined. We attempted to analyze the clinicopathologic significance of YAP1 expression and the correlation of the YAP1 levels with the progression, metastasis and prognosis of patients with gastric carcinoma. By immunohistochemistry, we determined YAP1 expression in 214 of primary gastric carcinoma (GC), 167 of matched normal gastric mucosa, 40 of chronic atrophic gastritis, 11 of dysplasia and 73 of intestinal metaplasia. The positive rate of YAP1 in gastric carcinoma was significantly higher than that in normal gastric mucosa, chronic atrophic gastritis and intestinal metaplasia. In the gastric cancers with lymph node metastasis, the positive rate of YAP1 was much higher than that in the group without lymph node metastasis. Moreover, gastric cancer patients with YAP1 overexpression demonstrated poorer prognosis than those with YAP1 negative staining. Finally, multivariate analysis of 191 patients with gastric carcinoma indicated that YAP1 overexpression, the invasion depth and lymph node metastasis were high hazard factors for gastric carcinoma. Our results demonstrated that YAP1 overexpression is correlated to the progression, lymph node metastasis and poor prognosis of gastric carcinoma, suggesting that overexpression of YAP1 might be an adjuvant factor for predicting lymph node metastasis, and a useful biomarker for the diagnosis and prediction of prognosis in patients with gastric cancers.