Tumor-associated macrophages promote tumor cell proliferation in nasopharyngeal NK/T-cell lymphoma

Objective: To explore the relationship between the number of tumor-associated macrophages (TAMs) and proliferative activity of tumor cells and the relationship between two macrophage biomarkers CD68 and CD163 in nasopharyngeal NK/T-cell lymphoma. Methods: Immunohistochemistry was used to reconfirm the diagnosis of nasal NK/T-cell lymphoma and detect the numbers of TAMs and the ki-67 label index of the tumor cells in all 31 cases. In addition, 12 cases of inflammatory cases were collected as controls, for which the immunostaining of CD68 and CD163 were done as well. Then staining results were analyzed with Pearson correlation and t test. Results: The number of TAMs was positively correlated with tumor proliferative activity (P = 0.024) in nasopharyngeal NK/T-cell lymphoma. The expression of CD68 and CD163 was closely related (P = 0.009), and the positive rate of CD68 was generally higher than CD163, however there is no statistical significance. Conclusion: The increase in numbers of TAMs in nasopharyngeal NK/T-cell lymphoma is related to higher proliferative index, indicating the TAMs play an important role in tumor proliferation. Meanwhile both CD68 and CD163 might be the markers for TAMs but CD163 would be the better one.