Loss of cytokeratin 10 indicates malignant transformation in actinic cheilitis.
OBJECTIVE
The aim of this study was to investigate the relationship the expression of cytokeratins (CK10 and CK13) and the cell proliferation index determined by Ki-67 of lip squamous cell carcinoma and actinic cheilitis with different degrees of dysplasia.


METHODS
Forty-five paraffin-embedded actinic cheilitis with and without dysplasia and 20 lip squamous cell carcinoma were analyzed by immunohistochemistry using anti-human anti-CK10, anti-CK13, and anti-Ki-67 antibodies.


RESULTS
The majority of actinic cheilitis showed immunopositivity for CK10 and CK13 with decrease or loss of expression in dysplastic areas. In lip squamous cell carcinoma of the lip, heterogeneous expression of CK13 and immunonegativity for CK10 were observed. There was a statistically significant difference between CK10 expression in lip squamous cell carcinoma and in actinic cheilitis with or without dysplasia (p < 0.001). The cell proliferation index was higher in actinic cheilitis with dysplasia and lip squamous cell carcinoma than in actinic cheilitis without epithelial dysplasia. A significant correlation was found between the intensity of the epithelial dysplasia and the cell proliferation index (p < 0.001).


CONCLUSIONS
These results provide evidence that there is a downregulation of CK10 expression in dysplastic areas of patients with actinic cheilitis and in those with lip squamous cell carcinoma (LSCC) and that the index of cell proliferation, determined by Ki-67, is directly correlated with the intensity of the epithelial dysplasia.


CONCLUSIONS
Altogether, these results suggest that CK10 expression and the epithelial cell proliferation index can help to identify malignant transformation in the lip region.
Department of Stomatology, Area of Pathology, Bauru School of Dentistry, University of São Paulo, Al. Dr. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 170120-901, Brazil. natggalvao@hotmail.com.
Natália Galvão
NG
Garcia
Department of Stomatology, Area of Pathology, Bauru School of Dentistry, University of São Paulo, Al. Dr. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 170120-901, Brazil. denisetostes@usp.br.
Denise Tostes
DT
Oliveira
Department of Community Dentistry, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
José Roberto Pereira
JR
Lauris
Department of Pathology, Botucatu School of Medicine, State University of São Paulo, Botucatu, São Paulo, Brazil.
Maria Aparecida Custódio
MA
Domingues
Department of Pathology, Botucatu School of Medicine, State University of São Paulo, Botucatu, São Paulo, Brazil.
Eliana Maria
EM
Minicucci
Department of Pathology, Lauro de Souza Lima Institute, Bauru, São Paulo, Brazil.
Cléverson Teixeira
CT
Soares
D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D002613:Cheilitis / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007633:Keratins / Q000378:metabolism*; D008048:Lip Neoplasms / Q000378:metabolism*
D007633:Keratins
Actinic cheilitis; Cell proliferation index; Epithelial dysplasia; Squamous cell carcinoma of the lip