UICC World Cancer Congress 2006

Objective:The purpose of this study is to detect the free cancer cells in peritoneal cavity of colorectal cancer patients by quantitative Real-time RT PCR method and investigate its clinical significance.

Methods:From May 2003 to Jan. 2004, peritoneal wash was obtained from 81 patients with colorectal cancer in Aichi cancer center. cDNA was synthesized from mRNA extracted from peritoneal washes by 2 kinds of primers ( Random primer and Oligo primer). Quantification of CEA and CK-20 mRNA was performed on a LightCycler instrument with hybridization probe.

Results:Both CEA mRNA value and CK-20 mRNA value significantly correlated with depth of tumor invasion, tumor stage, lymph node status. Sensitivity and specificity of CEA and CK-20 real-time RT-PCR with an appropriate cutoff value were 80%, 100%, and 100%, 100%, respectively, whereas those of conventional cytology were 33%, and 100%, respectively. (Conclusion): These results suggest that both CEA and CK-20 mRNA quantifications are sensitive and specific methods for detection of free cancer cells in the peritoneal washes of colorectal cancer. Further follow-up study is needed to demonstrate the clinical significance of CEA and CK-20 mRNA in peritoneal washes.