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

Loss of function of the tumor suppressor gene TP53 contributes to the development of several tumors.,We screened DNA samples from 47 patients with upper respiratory system squamous cell carcinomas for the presence of TP53 mutations. Exons 4 to 8 of the TP53 gene were amplified by the polymerase chain reaction, and mutations were identified by single-strand conformation polymorphism analysis.,The TP53 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 of TP53 mutations. There was an increasing number of mutations in the more undifferentiated tumors (P = 0.0594).,These findings suggest that TP53 mutations are associated with tumor differentiation, but not with the risk of lymph node metastasis in the group of patients analyzed.