p53 gene mutations as markers of tumor spread in synchronous oral cancers.

To demonstrate how genetic mutations may be used as specific markers for the study and management of head and neck squamous cell carcinomas. Mutations in the p53 gene were identified by DNA sequencing in synchronous primary head and neck squamous cell carcinomas from one patient. The polymerase chain reaction and mutant-specific oligomer probes were used to detect rare tumor cells in surgical margins, lymph nodes, and swabs of the oral cavity. Selected from a consecutive series of individuals with head and neck squamous cell carcinomas at a tertiary referral center. Two synchronous primary invasive cancers displayed different missense mutations in the p53 gene. The mutated sequence from one primary tumor was detected in metastases from both sides of the neck. Infiltrating cells from this biologically aggressive tumor were also detected by a polymerase chain reaction-based assay in a histologically normal surgical margin, accurately predicting tumor recurrence. p53 gene mutations were useful as molecular markers to distinguish between tumors in this case. The potential utility of detection of tumor cells in surgical margins and saliva by molecular techniques merits further investigation.