Background & objective: CXCL12 is a kind of chemokine. CXCR4, the specific receptor of CXCL12, is involved in metastasis of tumors. CXCR4/CXCL12 expression in cervical adenocarcinoma has seldom been reported. This study was to investigate the correlation of CXCR4/CXCL12 overexpression to lymph node metastasis and chronic inflammation in cervical adenocarcinoma.
Methods: CXCR4 and CXCL12 immunohistochemical staining and HE staining were performed in 35 specimens of cervical adenocarcinoma, including 8 with lymph node metastasis and 27 without. Marked expression of CXCR4 or CXCL12 observed in more than 90% tumor cells was defined as overexpression. Fisher's exact test, Chi-square test, and Pearson correlation test were used to analyze the results.
Results: All 35 specimens of cervical adenocarcinoma expressed CXCR4. The overexpression rate of CXCR4 was significantly higher in the cases with lymph node metastasis than in those without (62.50% vs. 22.00%, P<0.05), slightly higher in the IB cases with lymph node metastasis than in those without (33.33% vs. 26.01%, P>0.05), and significantly higher in the IIB cases with lymph node metastasis than in those without (80.00% vs. 0.00%, P<0.05). The positive predictive value of CXCR4 overexpression to assess lymph node metastasis was 45.45%, and the negative predictive value was 87.50%. A variable number of tumor cells in 33 specimens expressed CXCL12. The overexpression rate of CXCL12 was significantly higher in IB cases than in IIB cases either in tumors with lymph node metastasis (0.00% vs. 80.00%, P<0.05) or without (21.73% vs. 75.00%, P<0.05). CXCR4 overexpression was positively correlated to CXCL12 overexpression in the 23 IB cases without lymph node metastasis; but the correlation did not exist in the 3 IB cases with lymph node metastasis and the 9 IIB cases. All the 35 specimens were accompanied with chronic inflammation; the infiltrates were mainly lymphocytes. CXCL12 overexpression was not correlated to the infiltration degree of chronic inflammation.
Conclusions: CXCR4 overexpression indicates a higher lymph node metastasis potential of cervical adenocarcinoma. The overexpression rate of CXCL12 is increasing by the progression of tumors. The chronic inflammatory cells in cervical adenocarcinoma are not attracted by CXCL12.