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

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.

Epidemiology of Cutaneous T-Cell Lymphomas: A Systematic Review and Meta-Analysis of 16,953 Patients

“…UV exposure has also been suspected to play a role in the disease pathophysiology [ 40 ]. A recent study suggested the role of environmental toxic exposures to benzene and trichloroethylene in the pathogenesis of cutaneous lymphomas [ 41 ].…”

The Geographic Context of Racial Disparities in Aggressive Endometrial Cancer Subtypes: Integrating Social and Environmental Aspects to Discern Biological Outcomes

“…Spatial epidemiological cluster detection techniques, Local Moran’s I (LMI) [ 32 ], Gi* [ 33 ], and GeoMEDD [ 34 ] were used to investigate geographic patterns of non-endometrioid subtypes within the CCCC area in ArcMap (v = 10.7.1) [ 35 ]. Local Moran’s I and Gi* have been used widely in detection of cancer clusters [ 19 , 28 , 36 , 37 ], while GeoMEDD is a new approach developed in COVID-19 spatial syndromic surveillance [ 34 ]. Local Moran’s I and Gi* operate on aggregate geographic units, such as census tracts, in this case.…”

Understanding and Addressing Disparities in Patients With Hematologic Malignancies: Approaches for Clinicians

“…An analysis of the Environmental Protection Agency's National Air Toxics Assessment database for the state of Georgia found that higher rates of cutaneous T-cell lymphoma were geographically clustered in regions with higher levels of benzene and trichloroethylene exposure. 20 Future studies should explore relationships between environmental exposures and disparities in incidence and clinical presentation to define explanatory models and develop interventions for prevention strategies.…”