Clustering of cutaneous T-cell lymphoma is associated with increased levels of the environmental toxins benzene and trichloroethylene in the state of Georgia

• Type of Material: Article
• Authors: Lindsay Clough, Emory University; A. Rana Bayakly, Georgia Department of Public Health; Kevin Ward, Emory University; Mohammad Khan, Emory University; Suephy Chen, Emory University; Mary Lechowicz, Emory University; Christopher Flowers, Emory University; Pamela Allen, Emory University; Jeffrey Switchenko, Emory University
• Language: English
• Date: 2020-01-14
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © American Cancer Society 2020.
• Final Published Version (URL): http://dx.doi.org/10.1002/cncr.32665
• Title of Journal or Parent Work: Cancer
• Volume: 126
• Issue: 8
• Start Page: 1700
• End Page: 1707
• Grant/Funding Information: The research reported in this publication was supported in part by the Biostatistics and Bioinformatics Shared Resource of Winship Cancer Institute of Emory University and the National Institutes of Health/National Cancer Institute under award P30 CA138292.
• Keywords: Mortality; Risk; cutaneous T-cell lymphoma; Trends; volatile organic compounds; spatial epidemiology; Environmental Protection Agency (EPA); Patterns; Life Sciences & Biomedicine; Oncology; Exposure; environmental epidemiology; Science & Technology; Stage
• Research Categories: Environmental Sciences; Health Sciences, Epidemiology; Health Sciences, Oncology; Health Sciences, Occupational Health and Safety

Abstract

BACKGROUND: Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma arising in the skin. Geographic clustering of CTCL has recently been reported, but its association with environmental factors is unknown. Benzene and trichloroethylene (TCE) are environmental toxins with carcinogenic properties. The authors investigated associations between geographic clustering of CTCL incidence in the state of Georgia with benzene and TCE exposure. METHODS: The statewide county-level incidence of CTCL within Georgia was obtained from the Georgia Cancer Registry for the years 1999 to 2015. Standardized incidence ratios (SIRs) were calculated by dividing observed cases by expected cases using national incidence rates by age, sex, and race. Clustering of CTCL was analyzed using spatial analyses. County-level concentrations of benzene and TCE between 1996 and 2014 were collected from the Environmental Protection Agency’s National Air Toxics Assessment database. Linear regression analyses on CTCL incidence were performed comparing SIRs with levels of benzene and TCE by county. RESULTS: There was significant geographic clustering of CTCL in Georgia, particularly around Atlanta, which was correlated with an increased concentration of benzene and TCE exposure. Among the 4 most populous counties in Georgia, CTCL incidence was between 1.2 and 1.9 times higher than the state average, and benzene and TCE levels were between 2.9 and 8.8 times higher. CONCLUSIONS: The current results demonstrate nonrandom geographic clustering of CTCL incidence in Georgia. To the authors’ knowledge, this is the first analysis to identify a correlation between geographic clustering of CTCL and environmental toxic exposures.