Inverse association of colorectal cancer prevalence to serum levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in a large Appalachian population

Table 6 Association of serum perfluorooctanoate (PFOA) and perfluorooctane sulfonic acid (PFOS) levels to colorectal cancer diagnosis in adults aged 21 and older, by year of diagnosis and period of residence in affected water district

	Resident since 1995 or before and including only CRC cases diagnosed 2000 or later (N=21,233 controls, 71 CRC cases)				Resident since 1990 or before and including only CRC cases diagnosed 2000 or later (N=15,533 controls, 60 CRC cases)
	Cases	Controls	Odds ratio (95% CI)*	P	Cases	Controls	Odds ratio (95% CI)*	P
*PFOS quartiles*
First	42	5278	1.00		37	3884	1.00
Second	12	5312	0.19 (0.09,0.38)	<0.00001	9	3884	0.18 (0.08,0.40)	0.00002
Third	7	5322	0.13 (0.06,0.27)	<0.00001	7	3864	0.14 (0.06,0.30)	<0.00001
Fourth	10	5321	0.12 (0.06,0.23)	<0.00001	7	3901	0.12 (0.06,0.24)	<0.00001
Test for trend				<0.00001				<0.00001
*PFOA quartiles*
First	28	5284	1.00		25	3870	1.00
Second	7	5325	0.25 (0.11,0.55)	0.001	9	3921	0.24 (0.10,0.56)	0.001
Third	21	5313	0.37 (0.19,0.70)	0.002	13	3828	0.32 (0.16,0.66)	0.002
Fourth	15	5311	0.43 (0.24,0.78)	0.005	13	3914	0.38 (0.20,0.72)	0.003
Test for trend				0.001				0.001

*Odds ratios adjusted for age, race, gender, socioeconomic status (years of education, annual household income, and employment status/disability), marital status, lifestyle factors, BMI, menopausal status, and comorbidity. Lifestyle factors include smoking (never, former, current); current alcohol consumption (yes/no); vegetarian diet (yes/no); exercise (regular exercise program (yes/no); comorbidity includes physician diagnosis of chronic comorbid condition (heart, kidney, liver, immune, connective tissue, and thyroid disease, stroke, hypertension, dyslipidemia, diabetes, chronic obstructive pulmonary disease, or asthma) and current treatment for hypertension or hyperlipidemia.

ISSN: 1471-2407