BACKGROUNDPeritoneal dissemination is the most common pattern of metastasis in advanced gastric carcinoma with serosal invasion. In the present study, we reported the clinical relevance of a new diagnostic method involving RT-PCR, using survivin as the target gene, for the detection of free cancer cells in peritoneal washes.

METHODSIntraoperative peritoneal washes were obtained from 48 patients who underwent surgery for gastric cancer. RT-PCR analysis with primers specific for survivin and conventional cytological examinations were both performed.

RESULTSSurvivin mRNA was not detected in any peritoneal wash samples from patients with benign disease, but was detected in 28 of 48 samples taken from patients with gastric cancer and in all metastatic nodules. Survivin expression in the peritoneal cavity significantly correlated with depth of cancer invasion, lymph node metastasis, and TNM stage. There were 92% of clinically evident peritoneal metastasis cases showed detectable survivin expression. The combination of survivin RT-PCR and cytological examination yielded positive results in 66.7% (32/48) of patients with gastric cancer, much higher than the results produced by cytological method alone.

CONCLUSIONSSurvivin mRNA detected in peritoneal lavage fluid might indicate the presence of free cancer cells in the peritoneal cavity. The high sensitivity of the RT-PCR-based survivin assay suggests that survivin serves as a molecular marker for detecting peritoneal micrometastasis. Its ubiquitous expression in peritoneal cancer cells and metastatic nodules also suggests a promising future therapeutic strategy based on survivin inhibition for cases of gastric cancer involving peritoneal metastasis.