A population-based case-control study of lung cancer in Appalachian Kentucky: The role of environmental carcinogens (Feltner scope)

Appalachian Kentucky has one of the highest incidence rates of lung cancer in the United States (115.2 per 100,000 compared to 61.6 per 100,000 nationally). The disproportionately high incidence is not explained by tobacco alone; environmental carcinogens in the form of trace elements are known to promote carcinogenesis by several mechanisms, including increased oxidative stress, inflammation, DNA damage, and reduced DNA repair efficiency. Studies of environmental exposure in this Appalachian region are incomplete; however, preliminary analysis of trace element content in toenail samples reveals higher levels of arsenic, chromium and nickel in Appalachian Kentucky residents compared with other Kentuckians. These findings justify further investigation of the role that trace elements play in the development of lung cancer in this region. Appalachian Kentucky is the ideal setting for this study because of its high lung cancer burden, low population migration rate and disproportionately high level of environmental toxins.