Table 3.

Summary results for the association of per- and polyfluoroalkyl substances (PFASs) with cancer risk among Japanese

Reference	Study period	Outcome	Design	Study subjects			Exposure assessment	Exposure	Exposure level (median or range among control group)	Category	Odds ratios	95% confidence interval	P for trend	Confounding factors
				Definition	Age range	Number of subjects
Itoh et al. [53]	Enrolment 2001–2005	Breast cancer	Hospital-based case–control	Cases: histopathologically confirmed, Controls: medical check-up examinees matched by age and area of residence	20–74 years old	401 cases and 401 controls	Serum samples measured by in-port arylation gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS)	Total PFOS (ng/mL)	7.63	Quartile 1	1		0.0001	Adjusted for body mass index, height, menopausal status and age at menopause, age at first childbirth, family history of breast cancer, smoking status, strenuous physical activity in the past five years, moderate physical activity in the past five years, age at menarche, number of births, breastfeeding duration, alcohol intake, isoflavone intake, education level, serum total concentrations of polychlorinated biphenyls, fish and shellfish intake, vegetable intake, and calendar year of blood sampling
									12.2	Quartile 2	0.38	(0.18–0.82)
									16.27	Quartile 3	0.31	(0.14–0.69)
									24.67	Quartile 4	0.15	(0.06–0.39)
								Total PFOA (ng/mL)	3.18	Quartile 1	1		0.001
									4.71	Quartile 2	0.37	(0.19–0.73)
									6.46	Quartile 3	0.39	(0.18–0.84)
									9.31	Quartile 4	0.20	(0.08–0.51)
PFOS Perfluorooctane sulfonate, PFOA Perfluorooctanic acid