Résumé
BACKGROUND AND OBJECTIVES: Development of second primary cancer is an important biological characteristic of head and neck squmaous cell carcinoma. In the past, the development of second primary cancer has been explained by the field cancerization theory. However, recent reports support the common common clonal origin theory. Common clonal origin theory states that following the initial transformation, the progeny of the transformed clone spread through the mucosa and gives rise to the geographically distinct but genetically related tumor. The objective of this study is to compare the expression pattern of p53, mdm-2, nm23 and TGFalpha which are proteins involved in the development, growth and metastasis of tumor in primary and second primary cancers of multiple head and neck cancer. MATERIALS AND METHODS: Expression of p53, mdm-2, nm23 and TGFalpha were analysed by immunohistochemical study of 12 paraffin embedded sections from 6 patients (3 synchronous tumors, 3 metachronous tumors) who were surgically treated for multiple head and neck cancer. RESULTS: p53, mdm-2, nm23 and TGFalpha were expressed in the same pattern in 3 patients (50%) of primary and second primary cancers. CONCLUSION: In our study, we observed the same expression patterns in 3 cases; however, it was difficult to conclude based on this result alone the clonality relationship between primary and second primary cancer. We suggest that further studies using molecular biological techniques are needed to identify the early genetic events of carcinogenesis.