A lack of association between p53 mutations and recurrent nasopharyngeal carcinomas refractory to radiotherapy

The object of this study was to determine the incidence of p53 mutation in recurrent nasopharyngeal carcinoma refractory to radiotherapy. Study Design: Prospective study. Methods: There were 31 patients enrolled in this study between 1995 and 1998. All patients had received radiotherapy but none of them had undergone chemotherapy or local salvage surgery previously. Results. The p53 status of each tumor was analyzed by polymerase chain reaction and by sequencing of exons 5 to 8 (codons 126-306). Five (16.1%) of 31 patients had mutations in the p53 gene, of which 2 were non-sense mutations, 2 were transition mutations, and 1 was a frameshift deletion mutation. The majority of the p53 mutations were found in exon 5. There is no significant difference in the incidence of p53 mutation compared with that of the previous reports for the primary disease. Based on the clinicopathologic data, there was no specific difference found between these 5 patients and the others. Conclusions. This study shows that p53 mutation is an infrequent event and may have no essential role in recurrent nasopharyngeal carcinomas.