Low Incidence of p53 Mutations in Well-differentiated Tongue Squamous Cell Carcinoma in Japan

Background: Despite an increasing number of patients suffering from squamous cell carcinomas of the tongue, little is known about the molecular mechanisms involved in the origin and development of these neoplasms. Methods: We screened microdissected tongue squamous cell carcinoma (TSC) specimens from 28 consecutive, previously untreated, Japanese patients for mutations in the p53 tumor-suppressor gene single-strand conformation polymorphism analysis (exons 5, 6, 7, 8) and direct genomic sequencing. Results: Among them, 24 tumor specimens were well differentiated, three moderately and one poorly differentiated, according to the WHO classification. Mutations in the p53 tumor-suppressor gene were detected in only two out of the 28 (7%) tumor specimens. One was well differentiated and the other was poorly differentiated. Conclusions: Our results suggest that p53 gene mutations are less frequent in well differentiated TSC. These results indicate that mutations in the p53 gene may not be strongly involved in the development of well differentiated TSC.