TP53 MUTATIONS IN UPPER AERODIGESTIVE SQUAMOUS-CELL CARCINOMAS FROM AGROUP, OF BRAZILIAN PATIENTS

BACKGROUND: LOSS Of function of the tumor suppressor gene TP53 contrib utes to the development of Several tumors. PATIENTS AND METHODS: We sc reened DNA samples from 47 patients with upper respiratory system squa mous cell carcinomas for the presence of TP53 mutations. Exons 4 to 8 of the TPS3 gene were amplified by the polymerase chain reaction, and mutations were identified by single-strand conformation polymorphism a nalysis. RESULTS: 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. Demograp hic variables, tumor site, stage, family history of cancer, and tobacc o smoking were not predictors of TP53 mutations. There was an increasi ng number of mutations in the more undifferentiated tumors (P = 0.0594 ). CONCLUSIONS: These findings suggest that TP53 mutations are associa ted with tumor differentiation, but not with the risk of lymph node me tastasis in the group of patients analyzed.