Abstract: Objective  To investigate the expression of chemokine ligand 12 / chemokine receptor 4(CXCL12 / CXCR4) axis in triple negative breast cancer and its relationship with lymph node metastasis.
Methods  From January 2017 to July 2019,the Department of Pathology of our hospital obtained 70 triple-negative breast cancer tissue samples and paired adjacent tissues,and 34 triple-negative breast cancer metastatic lymph node tissues.The expression of CXCL12 and CXCR4 in the samples were detected by immunohistochemistry,and their relationship with clinicopathological characteristics was analyzed.
Results  The proportion of CXCL12（+）,CXCR4（+）,CXCL12（+）/CXCR4（+） in cancer tissue was higher than that in adjacent tissues,the difference was statistically significant(P<0.05).The ratio of CXCL12（+）/CXCR4（+） in metastatic lymphoid tissue was higher than that in cancer tissue,the difference was statistically significant(P<0.05).Correlation analysis showed that CXCL12 and CXCR4 expression were positively correlated in cancer tissues(r=0.632,P=0.002).The lymph node metastasis rate and the proportion of stage Ⅲ-Ⅳ in CXCL12（+） patients were higher than those of CXCL12（-） patients(P<0.05),and the lymph node metastasis rate and the proportion of stage Ⅲ-Ⅳ in CXCR4（+） patients were higher than CXCR4（-） patients(P<0.05).The expression of CXCL12/CXCR4 biological axis was statistically significant with lymph node metastasis and clinical stage of triple negative breast cancer(P<0.05).
Conclusion  The expression of CXCL12/CXCR4 biological axis is closely related to the lymph node metastasis and clinical stage of triple negative breast cancer.The expression of CXCL12/CXCR4 may promote lymph node metastasis.

Key words: chemokine ligand 12, chemokine receptor 4, triple negative breast cancer, lymph node metastasis, clinical stage