Monitoring Expression of Melanoma Inhibitory Activity and Melanoma Inhibitory Activity 2 using Immunohistochemistry to Predict Lymph Node Metastasis in OSCC

The aim of this study was to investigate the expression of melanoma inhibitory activity (MIA) and MIA2 in oral squamous cell carcinoma (OSCC) primary tumor (PT) and lymph node metastasis (LNM) specimens and clarify its usefulness in predicting LNM. The expression of MIA and MIA2 was evaluated using immunohistochemistry in a total of 122 paraffin-embedded OSCC PT and 40 LNM specimens. Expression of MIA and MIA2 was observed in the cytoplasm of PT and LNM tumor cells. In PTs, MIA expression was significantly increased in cases with LNM (LNM-positive vs. LNM-negative, p=0.016). MIA2 expression tended to be higher in cases with LNM (LNM-positive vs. LNM-negative, p=0.080). The expression of both MIA and MIA2 was significantly upregulated in LNM specimens than in PTs (MIA, p=0.002; MIA2, p=0.013), and MIA expression was significantly higher in cases with extranodal extension (p=0.026). These results suggest that the expression of both MIA and MIA2 is increased in cases with LNM; thus, MIA and MIA2 may be useful markers for predicting LNM in OSCC.