ABSTRACT
Betel-quid chewing, which is closely related to the high incidence of oral cancer, is prevalent in Sri Lanka. p63 has a remarkable structural similarity to p53, suggesting an aberrant expression in oral cancer. Using anti-p63 antibody and immunohistochemistry, the present study investigated the expression pattern of p63 in oral epithelial lesions, including different types of squamous cell carcinoma (SCC), different grades of epithelial dysplasia, and submucosal fibrosis associated with betel-quid chewing. Nuclear immunoreactivity for p63 was detected in all the cases, including normal oral epithelium and epithelial lesions. In normal oral epithelium, nuclear positivity for p63 was observed in some of the basal cell layers and focally in the parabasal layer. Nuclear positivity increased in the epithelial lesions. The percentage of positive nuclei in the epithelial lesions was significantly higher than in normal epithelium (P < 0.01) and was also significantly higher in oral submucosal fibrosis than in epithelial dysplasia (P < 0.05). The results indicate that the overexpression of p63 in oral precancerous lesions and SCC in betel-quid chewers in Sri Lanka may be a useful marker for oral precancerous lesions.
Subject(s)
Areca/metabolism , DNA-Binding Proteins/metabolism , Epithelium/pathology , Mastication/physiology , Mouth Neoplasms/metabolism , Oral Submucous Fibrosis/metabolism , Trans-Activators/metabolism , Tumor Suppressor Proteins/metabolism , Adult , Epithelium/metabolism , Humans , Immunohistochemistry , Ki-67 Antigen/metabolism , Middle Aged , Mouth Mucosa/pathology , Sri Lanka , Transcription FactorsABSTRACT
In this study, we focused on p53 mutations in specific regions, including DNA-binding surface regions, to clarify the correlation between mutations within the specific regions of p53 and clinical outcomes of patients with oral cancers. We analyzed p53 mutations in 121 fresh primary oral squamous cell carcinomas (SCCs) by polymerase chain reaction-single-strand conformation polymorphism or a yeast functional assay. p53 mutations were detected in 51/121 (42%) cases. Mutation of p53 was not associated with any clinicopathological parameters; however, tumors containing specific p53 mutations, e.g. DNA-binding surface regions (L2, L3 and the LSH motif) and conserved regions (II-V), had significantly poorer prognoses than tumors with mutations outside of those regions. Moreover, locoregional failure, lymph node metastasis and the occurrence of subsequent distant metastasis were also significantly associated with mutations within DNA-binding surface regions. These data indicate that specific mutations of p53 could be important prognostic factors in oral SCCs.
Subject(s)
Carcinoma, Squamous Cell/genetics , Genes, p53/genetics , Mouth Neoplasms/genetics , Mutation , Aged , Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/secondary , DNA, Neoplasm/genetics , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Mouth Neoplasms/pathology , Polymerase Chain Reaction/methods , Polymorphism, Single-Stranded Conformational , Prognosis , Survival RateABSTRACT
Mucinous adenocarcinoma is characterized by large pools of extracellular mucin. The tumor has been reported in the nasal cavity, paranasal sinus, breast, colon, stomach, prostate, skin, and lung. Mucinous adenocarcinoma also arises as a primary tumor of the major salivary glands. However, its occurrence is exceedingly rare and has only recently been recognized. Only 9 cases in the major salivary glands have been reported. We present an additional case of MAC in the maxilla that was considered to have developed from a palatal minor salivary gland.
