ABSTRACT
BACKGROUND: In the normal host, there are a variety of cellular systems that ensure the accurate replication and repair of DNA. Recent evidence suggests that there are individual variations in the ability to preserve the genome. Certain individuals have defects in these checkpoints and have an inherent genomic instability. They are susceptible to the accumulation of DNA damage and are prone to carcinogenesis. This article examines the role of genomic instability in the development of head and neck cancer. RESULTS: Patients with either the chromosomal instability syndromes or the Li-Fraumeni syndrome have marked defects in either DNA repair or apoptosis. These patients are prone to have head and neck neoplasms develop. Head and neck cancer patients also have a diminished ability to repair DNA damage compared with the "normal" population. Abnormalities have been identified in mutagen sensitivity, the expression of DNA mismatch repair enzymes, the expression of p53, and telomerase activity when head and neck cancer patients are compared with controls. CONCLUSION: Subpopulations exist who have increased genomic instability. These individuals are at an increased risk for the accumulation of DNA mutations and the development of head and neck cancer. More research is needed to identify specific mechanisms of genomic instability and to further define the importance of this phenomenon.
Subject(s)
DNA Repair , DNA Replication , DNA, Neoplasm/genetics , Head and Neck Neoplasms/genetics , Carcinoma, Squamous Cell/genetics , DNA Damage/genetics , DNA Mutational Analysis , Genes, p53/physiology , Humans , Microsatellite Repeats/genetics , Mutagenicity Tests , Mutagens , Telomerase/metabolismABSTRACT
BACKGROUND: Tongue cancer is seen with increasing frequency in young individuals. There is controversy concerning the clinical course and outcome for oral tongue cancer in young patients. METHODS: A retrospective review of 36 patients under 40 years of age with squamous cell carcinoma of the tongue was performed. These patients were matched to an older population. The 5-year disease-free survival; rates of local, regional, and distant failure; and rate of second primary tumor were determined for both populations. RESULTS: The 5-year disease-free survival for the young patients was 62% versus 69% in the older population (p = .30). Ten of 36 (28%) of younger patients recurred locally versus five of 36 (14%) of the older patients (p = .11). Nine of 36 (25%) younger patients recurred regionally in the younger group versus six of 36 (17%) patients in the older group (p = .25). Sixteen of 36 (44%) of the younger patients had locoregional failure versus eight of 36 (22%) of the older patients (p < .05). The rates of metastatic disease and second primary lesions were similar in both populations. CONCLUSIONS: In this series, younger patients with squamous cell carcinoma of the oral tongue had a higher rate of locoregional recurrence rate than did older patients. This did not translate into a survival difference.