LAMC2 is a predictive marker for the malignant progression of leukoplakia

BACKGROUND: LAMC2 plays an important role in cancer invasion. The aim of this study was to (i) compare the immunoexpression of LAMC2 in different stages of oral squamous cell carcinoma (OSCC), early and advanced, and (ii) to evaluate LAMC2 as a marker of malignant transformation in leukoplakia. MATERIALS AND METHODS: The expression of LAMC2 was examined by immunohistochemistry in 50 surgical specimens of advanced OSCC assembled as tissue microarrays, and by cDNA microarray in 43 surgical specimens of advanced OSCC. LAMC2 expression was further examined in 39 surgical specimens of early OSCC and in 93 incisional biopsy specimens of leukoplakia of the tongue, which exhibited epithelial dysplasia. The relationship of LAMC2 expression score with clinico-pathological characteristics was analyzed. RESULTS: LAMC2 was remarkably upregulated in OSCC at the cancer-stroma interface. The grade of LAMC2 expression was significantly associated with the pattern and depth of invasion of OSCC. Foci of LAMC2-positive cells were observed in some cases of leukoplakia. The number and size of LAMC2-positive foci were significantly associated with the grade of dysplasia. The presence of LAMC2-positive foci was a significant predictive factor for the malignant progression of leukoplakia. LAMC2-positive leukoplakia had an approximately 11-fold increased risk of malignancy compared with LAMC2-negative leukoplakia. CONCLUSIONS: The results of this study highlight the value of LAMC2 as a marker of cancer invasion. LAMC2-positive foci in leukoplakia suggest an imminent risk of cancer. LAMC2 immunostaining is expected to contribute to a more precise assessment of the malignancy of leukoplakia.