【Abstract】ObjectiveTo discuss the possibility and clinical significance of SSX-1 mRNA used as specific marker for examining HCC cells in peripheral blood of HCC patients. MethodsUsing the RT-PCR method, the SSX1 mRNA of the peripheral blood was examined in 25 cases of HCC patients and 20 non-HCC patients. The same method was used to detect the expression of SSX-1 mRNA in the tumor tissues, para-tumor tissues, cirrhosis tissues and normal hepatic tissues. A randomized sample was extracted for DNA sequencing from positive electrophoresis expression samples of SSX-1 to examine the reliability of results. ResultsThe expression rates of SSX-1 mRNA were 60%(15/25) and 40%(10/25) respectively in tumor tissues of HCC and the corresponding peripheral blood. SSX-1 mRNA were not expressed in para-tumor tissues,cirrhosis tissues and normal hepatic tissues. The DNA sequence -confirmed that the RTPCR products were true target cDNA. No relationships were found between the expression of SSX-1 gene and clinical characteristics, such as age, sex, tumor size, TNM stage, extent of differentiation and serum AFP level (Pgt;0.05). However, in 33%(3/9) patients with normal serum AFP (lt;20 μg/L), specific expression of SSX1 mRNA was observed. ConclusionHigh specific expression of SSX-1 mRNA is observed in the peripheral blood of patients with HCC, it suggests that applying it as a tumor marker to detect HCC cells in peripheral blood is an adjuvant diagnostic tool. The expression of SSX-1 mRNA in the peripheral blood is observed in the group HCC patients whose serum AFP (lt;20 μg/L) are normal, which suggests that applying both SSX-1 mRNA and AFP as tumor markers together might be useful to improve the diagnostic accuracy for HCC.