An immunohistochemical study of the pericacellous oral mucosa -Relationship between epithelial dysplasia and expression of p53 and ki-67 protein

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14571919
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Kanagawa Dental College
• Principal Investigator: KAWAHARA Kenji Kanagawa Dental College, School of Dentistry, Assistant, 歯学部, 助手 (80247311)
• Project Period (FY): 2002 – 2003
• Keywords: squamous cell carcinoma of oral mucosa / the pericancellous oral mucosa / potentiality to change malignancy / p53 protein / ki-67 protein / An immunohistochemical study / 予後

Research Abstract

Clinical and pathological studies were performed on 31 cases from 45 lesions with abnormal mucous membranes around squamous cell carcinoma of oral mucosa, and nuclear DNA in the relevant cells was quantified. The following results were obtained.
1) Cases whose primary tumor was at a stage equal to or less than T2 in size were most frequent (87.1%), while on a histopathological findings, the squamous cell carcinoma of well differentiated type with mildly cellular atypia were commonest (87.1%).
2) Visual inspection of abnormal mucous membranes around carcinoma reveals that leukopathic type were the most common (67.1%), followed by a mixture of leukopathic and erythromatous type (16.1%), and verrucous type (6.5%).
3) Regarding the positional relationship between carcinomas and abnormal mucous membranes, the cases (type I) in which a carcinoma was present within the confines of the abnormal mucous membranes were most frequent (48.4%),followed by a second group (type II) in which the two were opposed to each other (32.3%) by a third group (type III) in which the two were separated each other (6.4%), and by a fourth group in which types II and III were intermingled (12.9%).
4) When classified on a histopathological basis, the abnormal mucous membranes lacking dysplasia accounted for 12.9%, those with slight dysplasia, 51.6%, those with moderate dysplasia, 19.4%, ad those with severe dysplasia, 16.1%.
5) Regarding the DNA ploidy patter, diploidy pattern was observed in 30.4% of the carcinoma cells studied d aneuploidy pattern was observed in 69.6% of the cases while the equivalents for abnormal mucous membranes cells were 54.2% and 45.8%, respectively.
6) Generally speaking, the frequency of the abnormal mucous membranes cells with a variation and exceeding 4C with respect to nuclear DNA content is at a midpoint between the corresponding values for the carcinima cells and the normal epithelial cells. However, in the four cases with a diploidy pattern and in the five cases with an aneuploidy pattern, the frequency of cells exhibiting a variation and exceeding 4C was below the lower limit observed in carcinoma cells.
7) No apparent correlation was observed between the presence of dysplasia and the DNA ploidy pattern of the cells involved. Dysplastic cells showed a higher frequency of cells with a variatio and exceeding 4C with respect to the nuclear DNA content than did non-dysplasia, no significant differences were observed.
On the basis of the above it is likely that the abnormal mucous membranes around carcinoma of oral mucosa may act as a basis of development from which such tumors are generated, and that the mucus membranes which have a higher frequency of cells with an aneuploidy pattern or a variation and exceeding 4C with respect to nuclear DNA content, suggest a strong potentiality to change malignancy.