Clinical significance of zinc-finger E-box binding homeobox 1 mRNA levels in peritoneal washing for gastric cancer.

Zinc-finger E-box binding homeobox 1 (ZEB1) is an important regulator of epithelial-to-mesenchymal transition and is associated with various types of metastasis. Gastric cancer patients often develop peritoneal carcinomatosis, of which the detection of free cancer cells in the peritoneal washes is an important predictor. We analyzed the correlation of ZEB1 mRNA levels in the peritoneal washing (pZEB1) with clinicopathological variables and survival in 107 gastric cancer patients who underwent surgery and peritoneal washing cytology. Reverse transcription-polymerase chain reaction was performed to quantify pZEB1. The patients were classified into the pZEB1 (n=27) and the pZEB1 (n=80) groups based on their pZEB1 expression. pZEB1 was statistically correlated with pathological T stage (P=0.03) and vascular involvement (P=0.03). At 5 years, the disease-specific survival was 36.4% for the pZEB1 group and 64.7% for the pZEB1 group (P=0.02), whereas the disease-free survival rate was 46.9% for the pZEB1 group and 83.0% for the pZEB1 group (P=0.03). When subclassified into 4 categories based on washing cytology and pZEB1, survival was significantly lower in the pZEB1 compared to the pZEB1 group (cytology -negative group, P=0.01; cytology -positive group, P=0.13). Therefore, pZEB1 may add valuable information to conventional peritoneal washing cytology as a prognostic determinant in gastric cancer.