Immunohistochemical analysis of neutrophils, interleukin-17, matrix metalloproteinase-9, and neoformed vessels in oral squamous cell carcinoma

Abstract

Background: Tumor-associated neutrophils (TAN), matrix metalloproteinase-9 (MMP-9), interleukin-17 (IL-17), and angiogenesis have been proposed as prognostic biomarkers of malignant tumors. The purpose of this study was to investigate these inflammatory markers as prognostic factors for oral squamous cell carcinoma (OSCC).

Methods: Specimens of OSCC (n = 30), healthy oral mucosa (negative control, n = 10), oral leukoplakia (n = 10), and apical granuloma with abscess (positive inflammatory controls, n = 10) were immunostained for CD66b (neutrophils), MMP-9, IL-17, and CD105 (neoformed microvessels). Semiquantitative (IL-17) and quantitative (CD66b, IL-17, MMP-9, and CD105) analyses were performed. Clinical information (TNM stage, metastasis, recurrence, and survival) and tumor histological grade were also obtained.

Results: Positivity for TAN, MMP-9, IL-17, and CD105 was higher in OSCC than in the negative control (P < 0.05) and oral leukoplakia, but similar to the positive inflammatory control. Coincident high counts of inflammatory markers (CD66b, MMP-9, IL-17, and CD105) were associated with lymph node metastasis of OSCC. Associations between high numbers of neoformed microvessels and advanced clinical stage and a higher degree of malignancy were also demonstrated.

Conclusions: Combined positivity for TAN, MMP-9, IL-17, and CD105 appears to be associated with the metastasis-prone phenotype of OSCC.

Keywords: angiogenesis; inflammation; interleukin-17; neutrophils; oral squamous cell carcinoma.