Relationships between tumor microenvironment and clinicopathological parameters in meningioma

To evaluate the relationship between the subtype of cells/cellular constituents (the density of T lymphocyte subsets, B lymphocyte, macrophages, and FOXP3 positive cells in 93 patients with meningioma, WHO grades I and II) in the tumor microenvironment and clinicopathological parameters (gender, age, tumor location, size, recurrence and pathological type) of meningioma.

Immunohistochemical demonstrations of CD20 and CD4 lymphocytes, CD68, and FOXP3 expression were performed. In order to assess the densities of CD4, CD20, CD68 and FOXP3 positive cells in 93 meningioma patients, the results were derived from independent reviews by two pathologists. Chi-square test was used for independent samples.

There were no relationships between the CD4(+), CD68(+) cell subsets and patients' age, sex, tumor size, grade and the recurrence of tumor. However, patients with recurrence had a significantly higher density of CD20(+) B cells compared to patients with no recurrence (P = 0.003). For the Foxp3(+) cell subset, results showed us that more female patients had high density of Foxp3(+) cells compared with male patients, while the opposite results were observed in the low density group (P = 0.009). Furthermore, the density of Foxp3(+) cells was significantly correlated with the tumor size (P = 0.004) and the pathological types (P = 0.004).

Results in this study demonstrate that higher CD20(+) B cell density in the tumor is associated with lower tumor recurrence and the density of Foxp3(+) cells is significantly correlated with the patients' sex, tumor size and the pathological types. The results also suggest that understanding of the cellular constituents of tumors and the tumor microenvironment may help investigate the tumor pathogenesis and immunotherapies in meningioma.