Clinicopathologic significance of laminin-5 gamma 2 chain expression in squamous cell carcinoma of the tongue - Immunohistochemical analysis of 67 lesions

BACKGROUND, The laminin-5 gamma 2 chain plays an important role in cell mig ration during tumor invasion and tissue remodeling. METHODS. Laminin-5 gamma 2 chain expression in squamous cell carcinomas of the tongue in 67 patients with Stage II, III, or IVA,B (excluding the cases with distant metastasis) was examined immunohistochemically to determine i ts associations with the clinicopathologic features of each tumor. The pred ominant staining patterns were categorized as follows: A, few or no tumor c ells were positive; B, part of the tumor nest periphery was positive; C, th e tumor nest periphery was circumferentially positive; or D, almost all the tumor cells were positive. RESULTS. Laminin-5 gamma 2 chain expression was observed clearly in tumor c ell cytoplasm. Of the 67 tumors examined, 6 (9%), 31 (46%), 19 (28%), and 1 1 (17%) showed staining patterns A, B, C, and D, respectively. With progres sion from staining pattern A to D, the number of immunopositive tumor cells increased significantly (P < 0.0001), and the tumor histology showed signi ficantly more infiltrative growth (P < 0.0001) and poorer differentiation ( P = 0.0021). Furthermore, both univariate (P = 0.0019) and multivariate (P = 0.0003; hazard ratio = 3.132) analysis of the patients' survival revealed that the prognosis became significantly poorer with progression from stain ing pattern A to D. CONCLUSIONS. Increased laminin-5 gamma 2 chain immunoreactivity, which may reflect a high invasive potential of cancer cells, is a factor indicative o f a poor prognosis for patients with squamous cell carcinoma of the tongue. Cancer 1999;85:2315-21. (C) 1999 American Cancer Society.