Abstract: Objective : To detect the expression of small breast epithelial mucin (SBEM) mRNA and carcinoembryon-ic antigen (CEA) glycoprotein in primary breast cancer and to investigate their clinical significance. Methods :The levels of SBEM mRNA and CEA glycoprotein were detected by RT-PCR and ELISA in the peripheralblood of 60 patients with breast cancer, 20 patients with fibroadenoma and 10 healthy adults. We usedSPSS10.0 to analyze the experimental data. Results : The positive rates of SBEM mRNA and CEA glycopro-tein expression in the peripheral blood of patients with primary breast cancer were 53.3% and 31.7%, respec-tively. In the peripheral blood of the 20 patients with fibroadenoma, SBEM mRNA expression was 0% andCEA glycoprotein expression was 5.0%. In the peripheral blood of the 10 healthy controls, the expression ofSBEM mRNA and CEA glycoprotein was 0%. The expression of SBEM mRNA and CEA glycoprotein was cor-related with axillary lymph node metastasis and TNM stage (P<0.05) but was not correlated with other clinicalcharacteristics (P>0.05). A combined test to detect serum SBEM mRNA and CEA glycoprotein showed in-creased accuracy and sensitivity (P<0.05). Conclusion : Combined detection of SBEM mRNA and CEA glyco-protein is valuable for the treatment and prognosis of patients with primary breast cancer.