Molecular screening. Prospects for a new approach.

Overview

Tumors arise through a series of genetic steps that involve alterations of various cellular genes. The recent revolution in molecular genetic techniques has allowed direct identification of genetic changes within tumors. Because these changes are intimately involved in tumor progression, they are specific markers for cancer. A novel assay based on the polymerase chain reaction allows detection of a rare cancer cell containing a specific point mutation among an excess background of normal cells. This technique has allowed identification of p53 gene mutations in pathologic tissue samples from primary head and neck cancer. A small population of cancer cells has been detected in a variety of histologically negative clinical specimens, including saliva, surgical margins, lymph nodes, and chyle. The precise detection of these rare cancer cells in various clinical samples has significant implications for otolaryngology-head and neck surgery. This approach holds promise for screening of head and neck cancer and may call for the reassessment of current histopathologic staging through utilization of new molecular genetic techniques.