p53 Mutation Patterns in Primary Head and Neck Squamous Cell Carcinomas and Their Metastatic Neck Nodes

Background and Objectives：Analysis of molecular events that occur during the evolution of head and neck squamous cell carcinoma has discovered multiple genetic changes, such as chromosomal abnormalities, activation of oncogenes, and inactivation of tumor suppressor genes. The involvement of p53 gene at the advanced tumor stage including lymph node metastasis has been demonstrated in head and neck cancers. Although there is some evidences for the persistence of p53 mutation of lymph node metastasis in head and neck cancer, no systematic study has been carried out to elucidate the persistence of p53 mutations and together with intratumoral heterogeneity of p53 mutations in primary and metastatic head and neck cancers. The purpose of this study was to reveal the pattern and intratumoral heterogeneity of p53 mutations in primary head and neck squamous cell carcinomas and their metastatic lymph node. Materials and Methods：In total 71 microdissected samples of primary tumors and their metastatic lymph nodes from 12 head and neck squamous cell carcinomas, exon 5 to 8 of p53 tumor supressor gene were analyzed by single strand conformational polymorphism and immunohistochemical study for the specimens. Resutls：In eight of 12 cases, mutational inactivations were identified. Involved exons were five cases of exon 5, two cases of exon 8 and one case of exon 7. In all of eight cases, mutations were identical in the primary and all of its metastatic samples. In microdissected study to obtain tumoral clones, mutation of p53 showed identical kind of p53 mutation for both primary and metastatic samples. Conclusion：p53 mutations of primary and metaststic head and neck squamous cell carcinomas showed identical kind of p53 mutation with intratumoral heterogeneity. (Korean J Otolaryngol 1998;41(7 :906-912