DISCORDANCE OF P53 STATUS IN MATCHED PRIMARY TUMORS AND METASTASES INHEAD AND NECK SQUAMOUS-CELL CARCINOMA PATIENTS

To study the use of p53 as a diagnostic tool in head and neck squamous cell carcinoma (HNSCC), we analysed 15 primary tumours (PT) and match ed lymph node metastases (LNM) for overexpression and mutations of p53 . The primary goal was to study whether differentiation between primar y and metastatic disease through their p53 status would be possible. I mmunohistochemistry for p53 protein (antibody BP 53-12-1) was performe d. Mutations of the p53 gene were detected by exon-specific amplificat ion of DNA (exons 4-9), followed by exon analysis using denaturing gra dient gel electrophoresis (DGGE). Mutant exons were sequenced. p53 ove rexpression was detected in seven (47%) of the PT and in seven (47%) o f the LNM. 6 patients (40%) exhibited p53 protein overexpression in bo th PT and LNM. 2 patients had a different p53 protein expression in ea ch sample. Mutations in the p53 gene were detected in 6 patients (40%) in the PT and in 7 patients (47%) in the LNM. In 2 patients (13%), th e same mutation was found in the PT and in the LNM. 9 patients (60%) h ad a different mutation in each sample. We conclude that a poor correl ation exists between p53 protein overexpression and p53 gene mutation in HNSCC. Also, a poor correlation for both detection techniques exist s, when PT and LNM are compared. The p53 status may seem to differ bet ween PT and LNM because of polyclonality in the PT. More sensitive det ection techniques could be promising. Copyright (C) 1996 Elsevier Scie nce Ltd