E0508 - Examining Associations Between Arsenic Pollution and Hepatocellular Carcinoma in Texas

Tuesday, October 25, 2022

3:00 PM – 5:00 PM ET

Location: Crown Ballroom

Presenting Author(s)

Adegboyega O. Olayode, MD, MPH

Emory University School of Medicine
Atlanta, GA

Adegboyega O. Olayode, MD, MPH¹, Abiodun Oluyomi, PhD², Omar Rosales, MPH, BS², Hemant Roy, MD², Hashem El-Serag, MD, MPH², Aaron Thrift, PhD²
¹Emory University School of Medicine, Atlanta, GA; ²Baylor College of Medicine, Houston, TX

Introduction: Alcohol is the major chemical risk factor for hepatocellular carcinoma (HCC) around the world, however other toxins including Arsenic have been shown to promote hepatocarcinogenesis in animals, though the exact mechanism is poorly understood. This ecological study assesses neighborhood-level HCC burden in Texas relative to arsenic exposure.

Methods: Using data from the Texas Cancer Registry, we identified a cohort of individuals diagnosed with HCC between 2011 and 2015. The primary exposure of interest is Arsenic pollution as reported in the 2011 National Air Toxics Assessment (NATA) inventory, this national screening assessment by the Environmental Protection Agency (EPA) uses emissions data to estimate health risks from toxic air pollutants. NATA calculates the concentrations of toxic air pollutants at the census tract (neighborhood) level; the inhalation exposure concentrations of Arsenic are in units of micrograms per cubic meter, however, for analysis, exposure concentrations were divided into deciles. Arsenic concentrations, demographic data, and the Area Deprivation Index (composite measure of neighborhood socioeconomic disadvantage that relies on 17 census variables drawn from these categories: poverty, housing, employment, and education) were included in multivariable Poisson-based modeling using negative binomial regression to evaluate the association between Arsenic exposure and HCC incidence in Texas.

Results: In a univariable model, the association between Arsenic inhalation exposure concentrations and HCC was not significant (IRR = 1.06 [95% CI, 0.98-1.16]). Whereas, in a multivariable model that included selected demographic and socioeconomic factors, results show that variation in census tract HCC incidence across Texas is significantly associated with the inhalation exposure concentrations of Arsenic. Based on our findings, in a typical Texas census tract, a 10-unit increase in decile classification of Arsenic inhalation exposure concentration increases the risk of HCC incidence by a factor of 1.30, while holding other explanatory variables constant (IRR = 1.30 [95% CI, 1.19-1.42]).

Discussion: Variation in HCC incidence across Texas’s census tracts is significantly associated with the inhalation exposure concentrations of Arsenic at the census tract level, higher Arsenic concentrations are associated with an increased incidence. This ecological finding needs to be further examined in direct association studies.

	Univariable Models^a						Multivariable Model^b
	IRR	95% CI			p value		IRR	95% CI			p value
Arsenic concentrations^c	1.06	0.98	-	1.16		0.159	1.302	1.194	-	1.419	<	0.001
Area Deprivation Index	1.17	1.16	-	1.20	<	0.001	1.618	1.444	-	1.813	<	0.001
% Hispanic or Latino (NH)	1.08	1.07	-	1.09	<	0.001	1.092	1.080	-	1.105	<	0.001
% Non-Hispanic Asians	0.68	0.65	-	0.71	<	0.001	0.892	0.853	-	0.934	<	0.001
% Non-Hispanic African American	1.06	1.05	-	1.07	<	0.001	1.098	1.080	-	1.116	<	0.001
% Others; 2+ races^d	0.58	0.54	-	0.63	<	0.001			-
% Population ≥ 60 y.o.	1.19	1.15	-	1.22	<	0.001	1.406	1.359	-	1.455	<	0.001
% Population male	1.05	1.00	-	1.11		0.064	1.171	1.117	-	1.226	<	0.001
% Non-Hispanic White^e	0.91	0.90	-	0.92	<	0.001

Table: Relationships between HCC incidence in Texas (2011 to 2015) and inhalation exposure concentrations of Arsenic (2011 estimate). Texas census tracts; N = 5,205.
a. Univariable models where Arsenic exposure concentrations was regressed on the HCC incidence separately. Also, each covariate was regressed on the HCC incidence separately.
b. Multivariable model where Arsenic concentrations and the covariates (P value ≤ 0.10) were regressed on the HCC incidence simultaneously.
c. The 2011 National Air Toxics Assessment (NATA) inhalation exposure concentrations for Arsenic are in units of micrograms per cubic meter; for analysis, concentrations were divided into deciles.
d. Variable dropped from the multivariable model run because p value > 0.10.
e. To avoid model overfitting from multicollinearity among race/ethnicity, Non-Hispanic White excluded from multivariable model.

Disclosures:

Adegboyega Olayode indicated no relevant financial relationships.

Abiodun Oluyomi indicated no relevant financial relationships.

Omar Rosales indicated no relevant financial relationships.

Hemant Roy indicated no relevant financial relationships.

Hashem El-Serag indicated no relevant financial relationships.

Aaron Thrift indicated no relevant financial relationships.

Adegboyega O. Olayode, MD, MPH¹, Abiodun Oluyomi, PhD², Omar Rosales, MPH, BS², Hemant Roy, MD², Hashem El-Serag, MD, MPH², Aaron Thrift, PhD². E0508 - Examining Associations Between Arsenic Pollution and Hepatocellular Carcinoma in Texas, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.