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 p21WAF1, 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 p21WAF1. 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 p21WAF1. 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. p21WAF1 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 p21WAF1 immunostaining, notwithstanding similar profiles between non-dysplastic and dysplastic leukoplakias were observed.

Coexpression of p53 and Ki 67 and lack of c-erbB2 expression in oral leukoplakias in India

Oral cancer is commonly preceded by premalignant lesions and conditions. The clinician's ability to identify lesions at an increased risk of cancer development is critical for its control. The purpose of this study was to compare the expression of tumor suppressor gene p53, proliferation marker Ki-67, and oncogene c-erbB2 and to evaluate the relevance of their co-expression in the diagnosis of, and prognosis for, oral leukoplakia. In the present study, the expression of biomarkers was studied immunohistochemically in 55 cases of leukoplakia (26 without dysplasia, 29 with dysplasia) and 10 cases of normal epithelia. The Labeling Indices (LI) of p53 and Ki-67 were found to increase significantly with an increase in the grade of dysplasia. A significant correlation was also found between the LI of p53 and that of Ki-67. It was also observed that c-erbB2 expression was only cytoplasmic, indicating incomplete receptor degradation. Hence, it can be concluded from the present study that the increased expression of p53 and Ki-67 with an increase in the grade of dysplasia suggests that their co-expression may be used for the identification of high-risk lesions. Also, c-erbB2 has no pathogenetic role in early carcinogenesis in the studied population, although incomplete receptor degradation, as evidenced by cytoplasmic staining, may indicate an early change.

Diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignant and malignant lesions.

Background and Objectives: In vivo stains are prompt resources, which have emerged, in the recent years, to aid as clinical diagnostic tools in detecting early premalignant and malignant lesions. The aim of the study was to determine the diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignancies and malignancies and to evaluate the reliability of in vivo staining with toluidine blue and Lugol's iodine in the lesions at risk of malignancy. Materials and Methods: The study group comprised 30 subjects with clinically suspicious premalignant lesions and 30 subjects with clinically suspicious malignant lesions. All the lesions were stained consecutively with toluidine blue and Lugol's iodine and the dye retention were recorded with photographs. Depending on the retention of the dyes, the biopsy site was determined. The biopsy specimens were sent for histological confirmation and results were statistically analyzed. Results: The overall diagnostic accuracy of Lugol's iodine when used consecutively with toluidine blue stain in distinguishing premalignant lesions and malignant lesions was 90%. As the degree of differentiation of malignant lesions progressed toward more severity, they failed to show the retention of Lugol's iodine and the result was highly significant statistically, with a P value < 0.001. Interpretation and Conclusion: Lugol's iodine when used with toluidine blue helped in delineating the inflammatory lesions and was the mean source in determining clinically the degrees of differentiation of malignant lesions as the poorly differentiated malignant lesions without glycogen content failed to show Lugol's iodine retention. Toluidine blue with Lugol's iodine can be used as a pretherapeutic assessment of the biologic aggressiveness of the disease.

Argyrophilic nucleolar organizer regions in inflammatory, premalignant, and malignant oral lesions: a quantitative and qualitative assessment.

BACKGROUND AND OBJECTIVE: Argyrophilic nucleolar organizer regions (AgNORs) have found widespread application in the past, especially in tumor histopathology. This study was undertaken to evaluate the significance of various AgNOR parameters and to assess their role in differentiating hyperplastic, premalignant, and malignant lesions. MATERIALS AND METHODS: The study sample consisted of archival biopsy specimens of ten squamous cell carcinomas, ten premalignant lesions, and five inflammatory lesions. Two biopsies from normal mucosa acted as control. AgNORs were assessed both quantitatively and qualitatively. The data were analyzed using Student's independent t-test, one-way analysis of variance (ANOVA), and multiple range test (Tukey-HSD). RESULTS: Quantitatively significant difference existed in the number of AgNORs between the normal mucosa, inflammatory lesions, and carcinomas, but the premalignant lesions failed to differ significantly from the normal mucosa. The number of AgNORs was found to be related to epithelial proliferation. Qualitatively, in terms of size, shape, and pattern of distribution, the normal mucosa and inflammatory lesion were alike, but the premalignant and malignant lesions differed significantly from the normal, with a marked degree of AgNOR pleomorphism being observed in carcinomas. CONCLUSIONS: AgNOR quantity is strictly proportional to the proliferative activity of the cell and does not necessarily indicate malignancy. It is the qualitative characteristics of AgNOR that help to differentiate hyperplastic, premalignant, and malignant lesions.

Biochemical changes of saliva in tobacco chewers tobacco smokers, alcohol consumers, leukoplakia and oral cancer patients.

Normal salivary function is considered to be critical for the maintenance of healthy oral mucosa. Oral fluids provide an easily available non-invasive for the diagnosis of a wide range of diseases and clinical situations. The present study evaluated the variations in the biochemical constituents of saliva of leukoplakia and oral cancer patients when compared with that of the control group. 90 individuals were grouped into 6 categories with 15 individuals in each group. The groups included individuals without tobacco or alcohol habits, tobacco smokers, tobacco chewers, alcohol consumers, leukoplakia and oral cancer patients. There was significant alteration in the salivary biochemical composition of leukoplakia and oral cancer patients which could be attributed to the impairment of salivary gland function caused by tobacco and alcohol usage or by the disease process itself.