TP53 mutations do not correlate with locoregional recurrence in stage I tongue carcinomas.

BACKGROUND: The abrogation of the TP53 gene is considered to play a central role in the development of human cancers. Exons 5-8 harbor mutations most frequently, mainly of the missense type, resulting in accumulation of the p53 protein. The importance of these alterations as prognostic factors, are issues of controversy.

MATERIAL AND METHODS: Thirty-four patients suffering from stage I tongue carcinoma had been treated with a local surgical excision of the tumor. Seventeen patients had developed a local recurrence in the tongue or cervical (regional) metastases while 17 patients, matched for age and gender to the former group, had no recurring disease within follow-up. Protein p53 was detected through immunohistochemical (IHC) analysis using antibody CM1. Exons 5-8 of the TP53 gene were amplified through the Polymerase Chain Reaction (PCR). The presence of mutations analyzed by CDGE (Constant Denaturant Gel Electrophoresis) and detected mutations were subjected to sequencing.

RESULTS: 20 out of 34 tumors (59%) showed mutated TP53, 18 tumors were IHC p53 positive, but the correlation between CDGE and IHC was only 56%. Sequencing of the gene was possible in 8 cases.

CONCLUSIONS: Neither the presence of mutations nor immunostaining had any impact on the risk of recurrence expressed as life-table analysis of time to recurrence.