The purpose of this study is to determine the presence, expression and type of HPV
in HNSCC tumor specimens and to investigate markers of specific pathways of tumor
development, with particular attention to biomarkers and pathways that may be different
between HPV-positive and HPV-negative cancers, and between African American and European
South Carolina currently ranks 3rd in the nation in HNSCC mortality. HNSCC are often discovered as locally advanced T3 or T4 disease, when the risk of developing loco-regional recurrences within two years is up to 70%.
According to current estimates, up to 25% of all HNSCC cases, and 60% of oropharyngeal cancers are secondary to high-risk human papillomavirus (HPV), particularly HPV-16 which, in the populations studied thus far, is present in over 90% of HPV-related HNSCC.
South Carolina ranks third in the Nation in oral and pharyngeal cancer (OPCA) mortality. During the period 1997-2002, the overall age adjusted incidence rate of OPCA for men in South Carolina was 19.6 per 100,000 and in women was 6.8 per 100,000. In 1997-2002 the age-adjusted incidence rate of OPCA in AA men was 44.5% higher than the rate in EA men. In addition, the age-adjusted mortality rate for OPCA in AA men is almost 3-fold greater than in EA men. The relationship of HPV infection to health disparities in HNSCC remains entirely unexplored. This proposal fills an important gap in our knowledge of the causes of this important health disparity.
To address the issues described here above, we elected to focus on two possibilities:
1. One or more additional HR HPV types, other than HPV16, play a significant role in HNSCC of AA patients. At least one contributing factor to the disparity between EA and AA in HNSCC could be other HR HPV types.
2. Despite the different distribution of HPVs, HPV16 is the only HR HPV type that easily thrives in the oral cavity, and remains the only type associated with HNSCC in both AA and EA patients. The question as to why HNSCC is more frequent and more deadly in AA men is open and warrants an investigation of the molecular nature of the disease in both racial groups, by gene expression profiling. The idea that HNSCC may be a different disease in AA patients is not far-fetched, as there is evidence that breast and prostate cancer also develop and behave in distinct ways in the two racial groups.
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