TP53 mutations in upper aerodigestive squamous cell carcinomas from a group of brazilian patients

Background: Loss of function of the tumor suppressor geneTP53 contributes to the development of several tumors. Patients and methods: We screened DNA samples from 47 patients with upper respiratory system squamous cell carcinomas for the presence ofTP53 mutations. Exons 4 to 8 of theTP53 gene were amplified by the polymerase chain reaction, and mutations were identified by single-strand conformation polymorphism analysis. Results: TheTP53 mutations were demonstrated in 23 cases (49%). Mutations were distributed as follows: exon 4, 5 cases; exon 5, 4 cases; exon 6, 6 cases; exon 7, 4 cases; and exon 8, 4 cases. Demographic variables, tumor site, stage, family history of cancer, and tobacco smoking were not predictors ofTP53 mutations. There was an increasing number of mutations in the more undifferentiated tumors (P = 0.0595). Conclusions: These findings suggest thatTP53 mutations are associated with tumor differentiation, but not with the risk of lymph node metastasis in the group of patients analyzed.