Simultaneous detection of homozygous deletion and point mutations in tumor suppressor genes p16 and p53 by multiplex-PCR/SSCP analysis

Use of cytological specimens for p53 gene alteration detection in oral squamous cell carcinoma risk patients

AIMS

Recurrence and multifocal nature are two important characteristics of oral squamous cell carcinoma. Leukoplakia is the most frequent pre-cancerous oral lesion and, in most cases, it is not possible to predict malignant capacity. The objective of this study is to identify p53 alterations in cells taken from the oral cavity of at-risk patients.

MATERIALS AND METHODS

The following samples were collected from 34 patients with oral leukoplakia with and without previous carcinoma: oral rinse, a brush swabbed over the lesions and hair roots. Mutational analysis of the p53 gene was performed by single-strand conformation polymorphisms and confirmed by DNA sequencing.

RESULTS

We detected 11 mutations in p53 gene in oral cytological specimens. These alterations were observed only in brush cytology samples in patients without previous carcinoma, and in both samples (rinse and brush) in patients with previous carcinoma. Three of these patients had disease recurrence.

CONCLUSION

This non-invasive technique may be useful in the follow-up of at-risk patients, and introduces new possibilities to analyse molecular markers before malignant lesions are clinically apparent.