Article

The objective assessment of lifetime cumulative ultraviolet exposure for determining melanoma risk

Department of Geography, University of Southern California, Los Angeles, CA 90089-0255, United States. <>
Journal of Photochemistry and Photobiology B Biology (Impact Factor: 2.96). 01/2007; 85(3):198-204. DOI: 10.1016/j.jphotobiol.2006.08.002
Source: PubMed

ABSTRACT

Exposure to ultraviolet radiation has commonly been recognized as the most important environmental risk factor for melanoma. The measurement of UV exposure in humans, however, has proved challenging. Despite the general appreciation that an objective metric for individual UV exposure is needed to properly assess melanoma risk, little attention has been given to the issue of accuracy of UV exposure measurement. The present research utilized a GIS based historical UV exposure model (for which the accuracy of exposure estimates is known) and examined, in the case-control setting, the relative importance of UV exposure compared to self-reported time spent outdoors, in melanoma risk. UV estimates were coupled with residential histories of 820 representative melanoma cases among non-Hispanic white residents under 65 years of age from Los Angeles County and for 877 controls matched to cases by age, sex, race, and neighborhood of residence, to calculate the cumulative lifetime UV exposure and average annual UV exposure. For historical measures, when the participants resided outside the US, we also calculated UV estimates. While there was no increased risk of melanoma associated with self-reported time spent outdoors, the association between annual average UV exposure based on residential history and melanoma risk was substantial, as was the association between cumulative UV exposure based on residential history and melanoma. The time spent in outdoor activities appeared to have no significant effect on melanoma risk in any age strata, however, when adjusted for UV exposure based on residential history, time spent outdoors during young age significantly increased risk for melanoma. While there was some attenuation of risk when we excluded data from people resident overseas (as all other studies we are aware of have done), this did not significantly impact subsequent risk estimates of UV exposure on melanoma.

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    • "Calculating an individual's lifetime UV radiation exposure can be challenging[9]in the clinical setting, as it requires information on (1) the frequency and duration of UV exposures which can vary over a person's lifetime, and (2) the residential history, since UV index varies by geographic location. In the research setting, data on (1) has been gathered through face-to-face[3,5,6,101112131415or telephone interviews,[16,17][22]these questionnaires do not collect an complete residential and exposure history to allow for assessment of lifetime ultraviolet exposure. With regard to data collection and analysis, an accurate, clinically-useful tool should rapidly parse residential histories, including the durations of residence, and link them to UV indices, as all these factors can vary significantly across a lifetime[20,22,23]. "
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    ABSTRACT: Estimates of an individual’s cumulative ultraviolet (UV) radiation exposure can be useful since ultraviolet radiation exposure increases skin cancer risk, but a comprehensive tool that is practical for use in the clinic does not currently exist. The objective of this study is to develop a geographically-adjusted tool to systematically estimate an individual’s self-reported cumulative UV radiation exposure, investigate the association of these estimates with skin cancer diagnosis, and assess test reliability. A 12-item online questionnaire from validated survey items for UV exposure and skin cancer was administered to online volunteers across the United States and results cross-referenced with UV radiation indices. Cumulative UV exposure scores (CUES) were calculated and correlated with personal history of skin cancer in a case–control design. Reliability was assessed in a separate convenience sample. 1,118 responses were included in the overall sample; the mean age of respondents was 46 (standard deviation 15, range 18 – 81) and 150 (13 %) reported a history of skin cancer. In bivariate analysis of 1:2 age-matched cases (n = 149) and controls (n = 298), skin cancer cases were associated with (1) greater CUES prior to first skin cancer diagnosis than controls without skin cancer history (242,074 vs. 205,379, p = 0.003) and (2) less engagement in UV protective behaviors (p < 0.01). In a multivariate analysis of age-matched data, individuals with CUES in the lowest quartile were less likely to develop skin cancer compared to those in the highest quartile. In reliability testing among 19 volunteers, the 2-week intra-class correlation coefficient for CUES was 0.94. We have provided the programming code for this tool as well as the tool itself via open access. CUES is a useable and comprehensive tool to better estimate lifetime ultraviolet exposure, so that individuals with higher levels of exposure may be identified for counseling on photo-protective measures.
    Preview · Article · Dec 2016 · BMC Dermatology
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    • "However, this study only assessed the associations of skin cancers with sun exposure intensity at three specific time points (at birth, ages 15 and 30) in early life, and did not assess the associations of skin cancers with sustained UV exposure over long durations. Another surrogate measure to assess cumulative sun exposure that is less influenced by recall bias is UV radiation flux (Scotto et al, 1988, 1996; Jemal et al, 2000; Fears et al, 2002; Tatalovich et al, 2006). Based on residential histories, UV flux is calculated where UV flux units represent radiant energy per unit area and are measured in Robertson–Berger (RB) metre units (Fears et al, 2002). "
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    ABSTRACT: Background: Solar ultraviolet (UV) exposure estimated based on residential history has been used as a sun exposure indicator in previous case–control and descriptive studies. However, the associations of cumulative UV exposure based on residential history with different skin cancers, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC), have not been evaluated simultaneously in prospective studies. Methods: We conducted a cohort study among 108 578 women in the Nurses' Health Study (1976–2006) to evaluate the relative risks of skin cancers with cumulative UV flux based on residential history in adulthood. Results: Risk of SCC and BCC was significantly lower for women in lower quintiles vs the highest quintile of cumulative UV flux (both P for trend <0.0001). The association between cumulative UV flux and risk of melanoma did not reach statistical significance. However, risk of melanoma appeared to be lower among women in lower quintiles vs the highest quintile of cumulative UV flux in lag analyses with 2–10 years between exposure and outcome. The multivariable-adjusted hazard ratios per 200 × 10−4 Robertson–Berger units increase in cumulative UV flux were 0.979 (95% confidence interval (CI): 0.933, 1.028) for melanoma, 1.072 (95% CI: 1.041, 1.103) for SCC, and 1.043 (95% CI: 1.034, 1.052) for BCC. Conclusions: Associations with cumulative UV exposure in adulthood among women differed for melanoma, SCC, and BCC, suggesting a potential variable role of UV radiation in adulthood in the carcinogenesis of the three major skin cancers.
    Full-text · Article · Mar 2014 · British Journal of Cancer
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    • "Skin protection is especially important for children and adolescents. Early intense exposure to UV radiation is associated with higher rates of skin cancer [8-12], and regular sunscreen use during childhood and adolescence could reduce lifetime incidence of non-melanoma skin cancers by approximately 78% [13]. Adolescence, in particular, is a critical period for skin cancer prevention because adolescents and young adults have the lowest skin protection rates of all age groups [14], receive large amounts of UV radiation [15-17], and increase their UV exposure habits as they move into adulthood and are less influenced by their parents [10,18]. "
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    ABSTRACT: Adolescents put themselves at risk of later skin cancer development and accelerated photo-aging due to their high rates of ultraviolet radiation exposure and low rates of skin protection. The purpose of the current study was to determine which of the Integrative Model constructs are most closely associated with sunscreen use among high school students. The current study of 242 high school students involved a survey based on the Integrative Model including demographic and individual difference factors, skin protection-related beliefs and outcome evaluations, normative beliefs, self-efficacy, sunscreen cues and availability, intentions, and sunscreen use. Our analyses included multiple linear regressions and bootstrapping to test for mediation effects. Sunscreen use was significantly associated with female gender, greater skin sensitivity, higher perceived sunscreen benefits, higher skin protection importance, more favorable sunscreen user prototype, stronger skin protection norms, greater perceived skin protection behavioral control, and higher sunscreen self-efficacy. Intentions to use sunscreen mediated the relationships between most skin protection-related beliefs and sunscreen use. The current study identified specific variables that can be targeted in interventions designed to increase sunscreen use among adolescents.
    Full-text · Article · Aug 2011 · BMC Public Health
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