Award Date

5-2010

Degree Type

Thesis

Degree Name

Master of Public Health (MPH)

Department

Health Sciences

First Committee Member

Michelle Chino, Chair

Second Committee Member

Patricia Cruz

Third Committee Member

Carolee Dodge-Francis

Graduate Faculty Representative

Connie Mobley

Number of Pages

77

Abstract

Cancer is the second leading cause of death in the United States, and oral cancer remains the eighth leading cause of cancer death among US males. Although previous epidemiologic studies have found that overall rates of cancer, including oral cancer, have declined in the US in recent decades – these declines are neither uniform nor consistent within this population. Anecdotal evidence has suggested that rates of oral cancer in Nevada are relatively high, although no evidence was available to support these assertions.

Oral Cancer Epidemiology: Based upon this information, a detailed and thorough epidemiologic examination of oral cancer rates in Nevada was undertaken. Chapter 1 describes a landmark publication in the journal BMC Public Health, which clearly demonstrated that oral cancer rates are, in fact, rising in specific geographic areas. Moreover, the state with the highest documented sustained increases was Nevada. In addition, although previous research has demonstrated increasing oral cancer rates among women and minorities, due to increased wealth, status and access over these past few decades – the observed increases in Nevada’s oral cancer rates were overwhelmingly within the white male population.

Risk Factor Analysis: In a follow-up study to determine the factors responsible for the rising rates of oral cancer in Nevada, an in-depth analysis of the primary risk factor for oral cancer development (tobacco usage) was performed. Chapter 2 outlines this study, submitted for publication in the journal Tobacco-Induced Diseases. These results demonstrated that the increased incidence and mortality of oral cancer in Nevada was a state-specific phenomenon and not part of a larger, regional increase. Moreover, trend analysis revealed that tobacco usage rates, although historically higher and linked to other factors, such as lower pricing, taxes and fewer workplace smoking bans, were recently found to be declining. These findings are the first to provide evidence that suggests that rates of oral cancer within this specific geographic area may soon begin to decline.

Environmental Factors: In addition to tobacco usage (smoking), many other risk factors may play a role in the development of oral cancers. These additional risk factors include environmental factors, such as nutrition and diet, which are examined in Chapter 3. For example, the recent adoption for required folate fortification in some food products, which has been shown to reduce negative health outcomes related to folate deficiency, has also been demonstrated to increase the rate of growth in undiagnosed (but pre-existing) colorectal cancers. This raises the question of whether folate may play a similar and significant role in the accelerated growth of other slow developing cancers, such as oral cancers. The timing of folate fortification in the US parallels the increased incidence of oral cancer in Nevada, suggesting that this environmental influence may also play an important role in the development and progression of this disease.

Keywords

Epidemiology; Mortality rates; National Cancer Institute’s Surveillance; Environmental causes; Epidemiology and End Results (SEER) program; Nevada; Oral cancer rates; Public health; Tobacco use

Disciplines

Community Health and Preventive Medicine | Epidemiology | Oncology | Public Health

Language

English


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