OBJECTIVETo detect the CDH1 gene methylation of suspension cells in intraoperative abdominal lavage fluid from colorectal cancer patients, and to examine its association with clinicopathology and prognosis.

METHODSReal-time methylation-specific polymerase chain reaction (qMSP) was used to investigate the methylation status of the CDH1 gene promoter 5'-CpG islands from intraoperative abdominal lavage fluid in 102 patients with colorectal cancer. The associations between methylation of CDH1 genes and clinicopathologic features and prognosis were investigated.

RESULTSAmong the 102 colorectal cancer patients, aberrant methylation of CDH1 gene was detected in 47 patients. Significant associations were found between CDH1 methylation status and tumor size, growth pattern, differentiation, distant metastasis, and clinical staging (all P<0.05). The median progression-free survival was 25.98 months for CDH1 methylation group and 41.36 months for non-methylated group, and the difference was statistically significant (P<0.01). Cox model analysis revealed that CDH1 methylation status in intraoperative peritoneal lavage fluid was an independent factor associated with postoperative survival in colorectal cancer patients (50.23% vs. 86.51%, P=0.001).

CONCLUSIONSColorectal cancer patients with aberrant methylation of 5'-CpG of CDH1 gene promoter of suspension cells in abdominal lavage have higher malignancy, more metastasis and worse prognosis.