CDH1 methylation in preoperative peritoneal washes is an independent prognostic factor for gastric cancer

Background and Objectives To investigate the clinical value of CDH1 methylation in preoperative peritoneal washes (PPW) from gastric cancer patients. Methods CDH1 methylation was detected by real-time methylation specific-PCR in tumor tissues and corresponding PPW from 92 gastric cancer patients, gastric mucosa from 40 chronic gastritis patients and 48 normal persons. Results CDH1 methylation was found in 75 of 92 (81.5%) gastric cancer tissues, which significantly correlated with size, growth pattern, differentiation, lymphatic invasion, venous invasion, invasion depth, lymph node metastasis, distant metastasis, and TNM stage of tumor (all P??0.05). The percentage of CDH1 methylation in PPW was 48.9%, of which the A? value of ROC curve was 0.8 compared to that in gastric cancer tissues. KaplanMeier analysis showed that there was a significant difference in disease-free survival (DFS) between the patients with or without methylated CDH1 in their PPW (?2?=?109.64, P?