Ambient ultraviolet radiation exposure and hepatocellular carcinoma incidence in the United States

Table 1 Characteristics of HCC cases and comparison of counties where cases lived vs. all U.S. counties

	Cases (n = 56,245)	U.S. counties^a
Age at diagnosis (mean ± SD)	62.4 ± 11.6
Sex (n[%])
Male	43,357 (77.1)
Female	12,888 (22.9)
Race (n[%])
White	38,546 (68.5)
Black	7737 (13.8)
Asian or Pacific Islander	9305 (16.5)
American Indian or Alaskan Native	657 (1.2)
Region of residence at diagnosis
Northeast	7596 (13.5)
South	9995 (17.8)
Midwest	4084 (7.3)
West	34,570 (61.5)
Year of diagnosis (n[%])
2000–2007	23,589 (41.9)
2008–2014	32,656 (58.1)
Average UV from 1980 to 1999 (mW/m²) (mean ± SD)^b	214.4 ± 36.1	193.1 ± 24.2
Heavy alcohol consumption (mean ± SD)^b	8.3 ± 2.2	6.4 ± 2.1
Smoking status (mean ± SD)^b	23.9 ± 4.8	26.7 ± 3.6
Any physical activity (mean ± SD)^{b, c}	76.9 ± 5.8	71.7 ± 6.1
Obesity (mean ± SD)^{b, c}	25.7 ± 4.1	30.0 ± 3.9
Diabetes (mean ± SD)^b	11.4 ± 1.7	10.9 ± 1.9
Median household income ($10,000) (mean ± SD)^b	47.1 ± 11.1	35.3 ± 8.8
Bachelor’s degree or higher (mean ± SD)^b	26.1 ± 9.2	16.5 ± 7.8
Unemployed (mean ± SD)^b	6.5 ± 2.3	5.8 ± 2.7
Urbanicity (n[%])^b
Rural	460 (0.8)	21.1
Urban	55,785 (99.2)	78.8
PM_2.5 (μg/m³) (mean ± SD)^b	14.6 ± 3.1	12.6 ± 3.2
Occupation in agriculture, forestry, fishing, hunting, or construction (mean ± SD)^b	13.8 ± 8.4	13.9 ± 3.8
Drug poisoning mortality rate (per 100,000) (n[%])^b
0–2	617 (1.1)	23.1
2.1–10	50,429 (89.7)	70.4
≥ 10.1	5199 (9.2)	6.5
Foreign born (mean ± SD)^b	17.9 ± 12.1	3.4 ± 7.8

HCC hepatocellular carcinoma, PM _2.5 particulate matter <2.5 μm, SD standard deviation, SEER Surveillance, Epidemiology, and End Results, UV ultraviolet radiation
^aCharacteristics of the 3108 counties across the contiguous U.S. (including Washington, D.C.)
^bCounty-level information based on the county at diagnosis for cases from SEER
^cSex-specific any physical activity and obesity prevalence rates were averaged to estimate a total prevalence

ISSN: 1476-069X