Diffuse expression of laminin γ2 chain in disseminating and infiltrating cancer cells indicates a highly malignant state in advanced tongue cancer

SummaryThe expression of laminin (LN)γ2 chain in the primary lesions of 20 patients with advanced tongue cancer was analyzed. Positive expressions of LNγ2 were noted in all of the primary tissue specimens, however, the expression patterns clearly differed according to the mode of growth and invasion of cancer cells. In tumor nests where cancer cells preserved cell–cell adhesiveness and showed polar differentiation, LNγ2 was expressed only in the peripheral cells of the tumor nests; peripheral expression. On the other hands when cancer cells diminished their cell–cell adhesiveness and strongly infiltrated through stroma, almost all of the cancer cells diffusely expressed LNγ2; diffuse expression. The peripheral expression of LNγ2 were noted in 13 patients and the diffuse expressions were noted in 7 patients. The rates of positive cervical metastases according to the expression type were 7/13 for the peripheral expression and 7/7 for the diffuse expression (p = 0.02). The diseases specific 3-year survival rates for the patients with the peripheral expression and the diffuse expression were 68% and 14%, respectively (p = 0.02). The diffuse expression of LNγ2 in the disseminating and infiltrating cancer cells might indicate a highly malignant state in advanced tongue cancer. Therefore, a more intensive treatment modality would be necessary for the patients with advanced tongue cancer showing the diffuse LNγ2 expression.