Overexpression of immunosuppressive cytokines is associated with poorer clinical stage of oral squamous cell carcinoma.

OBJECTIVE: The aim of this study was to evaluate the expression of IL-10 and TGF-beta2 in oral squamous cell carcinoma (OSCC) and its relationship with prognostic clinical and microscopic parameters. DESIGN: Immunohistochemistry was used to assess the expression of IL-10 and TGF-beta2 in OSCC samples from 43 patients who had undergone surgical excision and neck dissection. Metastatic lymph nodes were included in the study (n=23). Samples of healthy oral mucosa (n=20) were used as controls. The sections were evaluated using a semi-quantitative method in conjunction with staining intensity. RESULTS: Our findings showed that the expression of IL-10 and TGF-beta2 by neoplastic and stromal cells was high in most of the OSCC samples (>70% of samples), especially when compared to the controls ( congruent with10% of samples) (P<0.05). OSCC neoplastic cells in cervical lymph nodes were also positive for IL-10 and TGF-beta2. An association between high expression of IL-10 by neoplastic cells and advanced clinical stage (T3-T4) was verified (P=0.02). Although not statistically significant, the expression of TGF-beta2 was also augmented in advanced stage tumours. CONCLUSIONS: These data suggest that the ability of OSCC neoplastic cells to secrete immunosuppressive cytokines could contribute to clinical progression by maintaining a microenvironment conducive to evasion and tumour proliferation.