Cumulative prognostic value of p53 mutations and bcl-2 protein expression in head-and-neck cancer treated by radiotherapy

✍ Scribed by Oreste Gallo; Ilaria Chiarelli; Vieri Boddi; Corso Bocciolini; Luca Bruschini; Berardino Porfirio

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: French
• Weight: 145 KB
• Volume: 84
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19991222)84:6<573::aid-ijc6>3.0.co;2-r

✦ Synopsis

We investigated the prognostic significance of p53-gene mutation (exon 5-9) and bcl-2-protein expression in primary squamous-cell carcinoma of the head and neck (HNSCC) treated by curative radiotherapy (RT). Primary squamouscell carcinomas for analysis were obtained from 85 consecutive head-and-neck-cancer patients, with complete follow-up data. We detected bcl-2 protein in 24% (20/85) of HNSCC studied; 38 (45%) of the 85 tumours had cells bearing p53 mutations. A strong association was observed between tobacco exposure and bcl-2-protein expression (p ‫؍‬ 0.003), an association also evident in those patients who had a p53mutated carcinoma (p ‫؍‬ 0.049). Moreover, we found that most of the bcl-2-positive cancers (70%) were also mutated in the p53 gene (p ‫؍‬ 0.010). In univariate and in multivariate analyses, the simultaneous detection of bcl-2 expression and a p53-gene mutation in a tumour biopsy specimen was associated with greater risk of locoregional failure (p ‫؍‬ 0.002 and 0.001 respectively) and worse survival (p ‫؍‬ 0.045 and 0.033) within 5 years in HNSCC patients treated by RT. The present study shows a cumulative prognostic value of simultaneous detection of bcl-2 over-expression and p53-gene aberration in some primary HNSCC treated with conventional RT, and provides further evidence for cross-talk between p53 and bcl-2, suggesting that these genes are important determinants of radiation-induced apoptosis, thereby modulating resistance to RT.