Current Data on Risk Factor Estimates Does Not Explain the Difference in Rates of Melanoma between Hispanics and Non-Hispanic Whites.

Sonia Kamath,Myles G Cockburn,Kimberly A Miller

doi:10.1155/2016/2105250

Abstract

United States Hispanics have seven times lower melanoma incidence rates than non-Hispanic whites (NHW). It is unclear whether this difference can be explained solely by phenotypic risk factors, like darker skin, or whether modifiable risk factors, like sun exposure, also play a role. The purpose of this paper is to summarize what is currently known about melanoma risk factors among Hispanics and NHWs, and whether or not those differences could explain the difference in melanoma incidence. Through literature review, relative risks and prevalence of melanoma risk factors in Hispanics and NHWs were identified and used to calculate the expected rate in Hispanics and rate ratio compared to NHWs. We found that melanoma risk factors either have similar frequency in Hispanics and NHWs (e.g., many large nevi) or are less frequent in Hispanics but do not explain a high proportion of disease variation (e.g., red hair). Considering current knowledge of risk factor prevalence, we found that melanoma incidence rates in the two groups should actually be similar. Sun exposure behavior among Hispanics may contribute to the explanation for the 7-fold difference in melanoma rates. Currently, limited data exist on sun exposure behavior among Hispanics, but possibilities for improving primary prevention by further studying these practices are substantial.

Highlights

Hispanics are the largest ethnic group in the United States, and over the last few decades, rates of melanoma among Hispanics have steadily risen [1, 2]
We examined what is currently known about the risk factors for melanoma and their distribution among Hispanics and calculated expected rate ratios (NHW compared to Hispanic) for each risk factor based on published estimates of relative risk and risk factor prevalence in the two groups
Carrying relative risks (RRs) of 3.05, demonstrated an expected rate ratio of 1.04, and high chronic sun exposure accounted for no difference in expected melanoma rates between Hispanics and non-Hispanic whites (NHW)

Summary

Introduction

Hispanics are the largest ethnic group in the United States, and over the last few decades, rates of melanoma among Hispanics have steadily risen [1, 2]. Hispanics have significant heterogeneity of skin color and phototype (including light skin color), and it is well known that ultraviolet (UV) exposure plays a role in the development of melanoma regardless of skin type [8, 9]. It is unclear whether key melanoma risk factors, including increased numbers of nevi, freckling, poor tanning ability, and fair complexion, differ substantially between Hispanics and NHWs [10, 11]. Most studies have focused on determining relative risks (RRs) for melanoma in NHWs, and few estimate melanoma burden attributable to each risk factor [13, 14]

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