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Background : Human SSX) was first identified as gene involved in the t(X;18) tranlocation in synovial sarcoma and was included in cancer-testis antigen CTA) such as MAGE lately. SSX and MAGE are multigene families with more than 9 and 12 each genes. Normally, almost exclusively in the testis, their mRNA are expressed in various human tumors. However, the characteristics of these genes in colon cancer are relatively unknown Purpose: This study evaluated the prevalence of MAGE and SSX by reverse transcription-polymerase chain reaction (RT-PCR) with common primers and discussed clinical implications in colorectal cancer. Materials and Methods: Fresh tissue from 37 cases of primary colorectal adenocarcinoma and normal mucosa were evaluated by RT-PCR with original common primers and discussed clinical implications by analysis of clinical and pathological parameters with correlation of gene expression of Cox-2, VEGF, and Survivin by Immunohistochemistry . Results: Expression of MAGE and SSX were not observed in normal tissues. The colorectal cancer expressed SSX mRNA with 32.4%(12/37) and MAGE mRNA with 51.4%(19/37). The liver metastasis show significant positive correlation with regional lymph node metastasis(p=0.006), vascular invasion(p=0.001), perineural invasion(p=0.000), and co-expression of SSX and MAGE(p=0.024). Seventy-five(75)% of colorectal cancer with liver metastasis showed co-expression . The co-expression is also correlated with nuclear expression of Survivin (p=0.016), however not correlated with those of Cox-2 and VEGF. No significant relationships between expression of these genes and other clinicopathologic variables were found. Conclusion: Co-Expression of MAGE and GAGE may predict the possibility of liver metastasis derived from colorectal cancer, and the peptide of these cancer-antigen genes can be the target for therapy of colorectal cancer in Koreans Key Words : Colorectal cancer, co-expression of SSX and MAGE, Cox-2, VEGF, liver metastasis, target therapy

[Proc Amer Assoc Cancer Res, Volume 47, 2006]