Dietary Flavonoid Intake and Risk of Cutaneous Squamous Cell Carcinoma

Flavonoids are compounds found in a variety of foods, including blueberries, plums, apples, cherries, oranges, strawberries, spinach, dark chocolate, nuts, red wine, soy products and tea. Dietary intake of flavonoid-rich foods has been associated with decreased incidence of ovarian, pancreatic, and lung cancers, as well as colon adenomas.

Despite the interest in flavonoid intake for these other tumor types, specific epidemiologic data for cutaneous malignancies are lacking. In addition, our collaborators at the Hormel Institute, Drs. Zigang Dong and Ann Bode, have recently reported that RSK2 activation is a new potential mechanism for non-melanoma skin carcinogenesis, and this activation is inhibited by two flavonoids, kaempherol and eriodictyol, in models of skin cancer. Therefore, we propose an epidemiologic study to determine the effects of flavonoids on the risk of cutaneous squamous cell carcinoma.

The specific aim of this project is to determine the effect of dietary flavonoid intake on incidence of squamous cell carcinoma (SCC). We will use existing datasets from the Southeast Arizona Health Survey (SEAHS) 2 study to assess flavonoid intake in individuals with and without cutaneous squamous cell carcinoma. If an effect is detected, we will assess for the presence of a dose-response relationship. We will also evaluate subgroups within the flavonoid category, including flavonols, flavones, flavanones, flavan-3-ols, and anthocyanins, for their individual effects on incidence of squamous cell carcinoma within this population.

Potential confounders, including age, gender, energy intake, fat intake, education level, alcohol intake, smoking history, body mass index, sun exposure, history of actinic keratosis, ability to tan, and freckling, will be assessed, and a multivariate model will be constructed to determine an adjusted odds ratio through logistic regression. This analysis will use existing data from available, well-designed studies specific to this patient population to support our upcoming skin cancer SPORE application.