Evaluation of epithelial dysplasia adjacent to lip squamous cell carcinoma indicates that the degree of dysplasia is not associated with the occurrence of invasive carcinoma in this site.

Abstract

We analyzed the different grades of dysplasia in the epithelium adjacent to lip squamous cell carcinoma (LSCC), as a parallel to actinic cheilitis (AC) that suffered malignant transformation. Forty samples of epithelium adjacent to LSCC were histologically graded according to the World Health Organization (WHO) and the binary systems. The expression of mutated p53 was evaluated through immunohistochemistry. According to WHO system, 37.5% of the cases were graded as mild, 45% as moderate and 17.5% as severe dysplasia (P = 0.09). Considering the binary system, 90% of the cases were classified as low-risk and 10% as high-risk lesions. Mutated p53 was present in 73.3% of mild, 88.8% of moderate and 71.4% of severe dysplasia cases. Considering the binary system, 80.5% of the low-risk and 75% of high-risk lesions were immunopositive; 62.5% expressed the protein in both tumor cells and adjacent epithelium; 17.5% in adjacent epithelium only, and 7.5% in LSCC islands only (P = 0.03). We observed heterogeneous grades of epithelial dysplasia in the epithelium adjacent to LSCC, which indicates that the analysis of AC morphological features is insufficient to predict patient's prognosis and to determine a treatment decision. Positive expression of mutant p53 in mild dysplasia reinforces this idea.