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: 2.8). 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.

Download full-text


Available from: John P Wilson, Aug 13, 2015
1 Follower
  • Source
    • "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). "
    [Show abstract] [Hide abstract]
    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.British Journal of Cancer advance online publication, 4 March 2014; doi:10.1038/bjc.2014.43
    British Journal of Cancer 03/2014; 110. DOI:10.1038/bjc.2014.43 · 4.82 Impact Factor
  • Source
    • "The remaining 12 papers used remotely sensed data in studies of cancer. Seven papers used remotely sensed stratospheric ozone column data (U.S. National Aeronautics and Space Administration, Total Ozone Mapping Spectrometer ) for predicting tropospheric levels of ultraviolet radiation, typically in studies of skin cancer, but also as an indication of vitamin D levels in studies of other cancers (Slaper et al., 1998; Piacentini et al., 2004; Solomon et al., 2004; Garland et al., 2006; Mohr et al., 2006, 2007; Tatalovich et al., 2006). The remaining five papers used land surface remotely sensed data for environmental exposure assessment in cancer research (Table 1). "
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, geographic information systems (GIS) have increasingly been used for reconstructing individual-level exposures to environmental contaminants in epidemiological research. Remotely sensed data can be useful in creating space-time models of environmental measures. The primary advantage of using remotely sensed data is that it allows for study at the local scale (e.g., residential level) without requiring expensive, time-consuming monitoring campaigns. The purpose of our study was to identify how land surface remotely sensed data are currently being used to study the relationship between cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessment applications. We present the results of a comprehensive literature review of epidemiological research where remotely sensed imagery or land cover maps derived from remotely sensed imagery were applied. We also discuss the strengths and limitations of the most commonly used imagery data (aerial photographs and Landsat satellite imagery) and land cover maps.
    Journal of Exposure Science and Environmental Epidemiology 03/2009; 20(2):176-85. DOI:10.1038/jes.2009.7 · 3.05 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Malignant melanoma arises from epidermal melanocytes, the cells responsible for the production of the skin pigment melanin. The photoprotective role of melanin, which is transferred to neighboring keratinocytes, in UV-induced skin carcinogenesis, specifically in nonmelanoma skin cancers, has been well documented. Although melanocyte-resident melanin is expected to offer similar protection to melanocytes from UV-induced damage, UV radiation has long been suspected to have an etiologic role in cutaneous melanoma. However, nearly three decades of efforts using a variety of in vitro and in vivo models of human skin and mouse genetic models have produced conflicting data. Epidemiologic studies have also failed to establish a definitive association between UV exposure and risk of melanoma. In this review, we evaluate the dual role of the melanin pigment as a photoprotector as well as a photosensitizer and examine the evidence for association between melanin levels (constitutive and induced) and melanoma risk. We also discuss possible reasons for the lack of signature UV mutations in melanoma oncogenes known to date and potential alternative mechanisms to explain the role of UV in melanomagenesis.
    Photochemistry and Photobiology 03/2008; 84(2):528-36. DOI:10.1111/j.1751-1097.2007.00283.x · 2.68 Impact Factor
Show more