Expression of the cell cycle regulation proteins p53 and p21WAF1 in different types of non-dysplastic leukoplakias

OBJECTIVES: The aim of this study was to analyze the immunolabeling of two cell cycle protein regulators, p53 and p21(WAF1), in non-dysplastic leukoplakias with different epithelial alterations: acanthosis, hyperkeratosis and acanthosis combined with hyperkeratosis, and compare them with dysplastic leukoplakias. MATERIAL AND METHODS: This was a prospective cohort study involving 36 patients with oral homogeneous leukoplakias. Excisional biopsies were performed and the patients remain under clinical follow-up. The leukoplakias were divided into four groups: 6 acanthosis, 9 hyperkeratosis, 10 acanthosis combined with hyperkeratosis, and 11 epithelial dysplasias. Paraffin-embebeded sections were immunostained for p53 and p21(WAF1). Five hundred cells from the basal layer and 500 from the parabasal layer were counted to determine the percentage of positive cells. A qualitative analysis was also carried out to determine the presence or absence of immunohistochemical staining in the intermediate and superficial layers. Groups were compared with ANOVA (p<0.05). Pearson's correlation coefficient was used to test for associations between the two markers, p53 and p21(WAF1). RESULTS: No leukoplakia recurred and no malignant transformation was observed whitin a follow-up period of 3-6 years. The mean percentage of p53 staining in the basal and parabasal layers was similar in all groups. p21(WAF1) staining differed between layers was as follows: in the basal, only 3 to 4% of cells were stained, while in the parabasal, between 16 and 28% of the epithelial cells were stained in the four different studied groups with no statistically significant difference (p>0.05). CONCLUSIONS: Our findings failed to differentiate the non-dysplastic lesions by means of p53 and p21(WAF1) immunostaining, notwithstanding similar profiles between non-dysplastic and dysplastic leukoplakias were observed

Grading systems in head and neck dysplasia: their prognostic value, weaknesses and utility

Contains fulltext : 80594.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Grading of dysplasia, including head and neck lesions, continues to be a hotly debated subject. It is subjective and lacks intra- and inter-observer reproducibility due to the insufficiency of validated morphological criteria and the biological nature of dysplasia. Moreover, due to the absence of a consensus, several systems are currently employed. OBJECTIVES: The aims of this review are to:1) Highlight the significance of dysplasia and the importance of a valid method for assessing precursor lesions of the head and neck.2) Review the different histopathological classification systems for grading intraepithelial lesions of the head and neck.3) Discuss and review quality requirements for these grading systems. CONCLUSION: Regarding the different classification systems, data concerning the WHO classification system are the most available in current literature. There is no simple relationship or overlapping between the classification systems. Further studies should be done to see whether other systems have advantages above the current WHO system and to discover indications that could lead to an universal classification system for intraepithelial lesions of the head and neck