Mark Hyde

MMS

Huntsman Cancer Institute

PA-C

PLCO (Learn more about this study)

PLCO-16

Mar 29, 2013

Dietary and Socioeconomic Risk Factors of Melanoma

It is estimated that there will be more than 75000 cases of melanoma and nearly 10000 melanoma-related deaths in the U.S. this year. The lifetime risk of developing melanoma is 1 in 50. Despite efforts to educate and prevent, incidence rates of melanoma are still on the rise. Exposure to ultraviolet radiation whether natural or not, remains the only known modifiable risk factor. Current preventive strategies focus on avoidance of tanning beds, education of sun safe behaviors, and proper use of sun block or sun screen. While these primary prevention strategies are useful, secondary prevention strategies most importantly include early and accurate diagnosis and appropriate surgical treatment.
More recently, there has been some question about the effects of diet on melanoma risk and progression. There is a lack of sufficient evidence to concretely support or refute specific dietary factors as protective or harmful in regards to melanoma risk. One of the key dietary suspects in this process is vitamin D; a vitamin produced, in part, in the skin using the same radioactive rays that are known to contribute to melanoma risk. Vitamin A has also been evaluated in some studies with varying results.

A lower socioeconomic status (SES) has been shown to correlate with more advanced disease at diagnosis and a poorer prognosis. The exact reasons for this disparity are not completely clear. Finally, some aspects of metabolic syndrome have been studied in this context with varying outcomes. Using PLCO data, we propose to investigate vitamin D, vitamin A, BMI, blood pressure, and socioeconomic status as potential risk factors for melanoma. We also propose to evaluate the influence vitamin D and vitamin A have on stage of disease at diagnosis and length of survival. Reproductive factors, and tobacco and alcohol use will also be included in this data set as they may be contributory or confounding variables.

In order to accurately evaluate the relationship between these factors and melanoma, some data will be extracted from pathology reports of patients diagnosed with a primary melanoma. These data will include body site, histologic subtype of melanoma, Breslow depth, mitotic count and ulceration status where available.

Specific aim 1: To evaluate the influence of dietary vitamin D and vitamin A levels on the risk of melanoma.
Hypothesis 1.1: High vitamin A intake decreases the risk of melanoma.
Hypothesis 1.2: High vitamin D intake decreases the risk of melanoma.

Specific aim 2: To evaluate the influence of dietary vitamin D and vitamin A levels on the stage of disease, as measured by Breslow thickness, in patients diagnosed with melanoma.
Hypothesis 2.1: High vitamin D intake is related to a shallower Breslow thickness at the time of melanoma diagnosis.
Hypothesis 2.2: High vitamin A intake is related to a shallower Breslow thickness at the time of melanoma diagnosis.

Specific aim 3: To evaluate the effect of metabolic syndrome on melanoma risk.
Hypothesis 3.1: High blood pressure does not independently increase risk of melanoma.
Hypothesis 3.2: High BMI does not independently increase the risk of melanoma.

Specific aim 4: To evaluate the influence of SES on the stage at diagnosis and explore possible reasons for previous findings suggesting that low SES predicts more advanced disease and less favorable prognosis.
Hypothesis 4.1: Lower education (and occupation, where available) as a proxy for SES is a risk factor for melanoma, controlled for Breslow depth.
Hypothesis 4.2: Lower education (and occupation, where available) as a proxy for SES is a risk factor for deeper Breslow depth at diagnosis and subsequent melanoma-specific mortality.

Specific aim 5: To evaluate the effect of aspirin use on melanoma risk and Breslow depth.
Hypothesis 5.1: Regular intake of aspirin reduces the risk of melanoma
Hypothesis 5.2: Those who use aspirin regularly will have a shallower Breslow depth at diagnosis