Table 2.

Association of breast cancer risk factors with likelihood of p16^INK4, BRCA1 and ERα hypermethylation in healthy women

	p16INK4 hypermethylation				BRCA1 hypermethylation				ERα hypermethylation
	Negative	Positive	P-value	OR	Negative	Positive	P-value	OR	Negative	Positive	P-value	OR
	(n= 97)	(n= 44)		95%CI	(n= 83)	(n= 17)		95%CI	(n= 91)	(n= 9)		95%CI
Age
<34.7	51	19		1.00	49	10		1.00	55	4		1.00
≥34.7	45	25	0.27	1.5 (0.73,3.06)	34	7	0.99	1.00 (0.35,2.91)	36	5	0.48	1.9 (0.48,7.59)
BMI
<31.0	41	23		1.00	36	7		1.00	41	2		1.00
≥31.0	49	16	0.16	0.6 (0.29,1.36)	39	9	0.76	1.2 (0.39,3.48)	43	5	0.44	2.4 (0.43,12.92)
Age first birth
<21.8	19	11		1.00	24	2		1.00	25	1		1.00
≥21.8	22	9	0.53	0.7 (0.21,2.09)	17	3	0.43	1.7 (0.24,11.48)	16	4	0.15	5.5 (0.53,56.91)
Race
EA	43	28		1.00	43	8		1.00	48	3		1.00
AA	54	15	0.02	0.4 (0.2,0.9)	40	9	0.72	1.2 (0.43,3.44)	43	6	0.311	2.2 (0.53,9.48)
Current smoking
No	74	36		1.00	64	14		1.00	71	7		1.00
Yes	16	8	0.95	1.0 (0.40,2.62)	14	2	0.731	0.7 (0.07,3.40)	14	2	0.651	1.5 (0.27,7.72)
Current drinking
No	53	29		1.00	37	11		1.00	42	6		1.00
Yes	31	12	0.40	0.7 (0.32,1.58)	30	6	0.48	0.7 (0.13,3.20)	33	3	0.731	0.6 (0.15,2.74)
Ever drinking
No	35	9		1.00	30	7		1.00	34	3		1.00
Yes	55	32	0.06	2.3 (0.97,5.31)	45	9	0.78	0.9 (0.29,2.55)	50	4	1.001	0.9 (0.19,4.30)
Family history of cancer
No	55	15		1.00	54	5		1.00	56	3		1.00
Yes	39	24	0.04	2.3 (1.05,4.85)	24	11	0.004	5.0 (1.55,15.81)	30	5	0.141	3.1 (0.7,13.92)
Family history of breast cancer
No	72	34		1.00	67	11		1.00	74	4		1.00
Yes	23	8	0.51	0.7 (0.30,1.82)	13	6	0.07	2.8 (0.88,8.95)	14	5	0.011	6.6 (1.58,27.71)

¹Fisher’s exact test.

Odds ratios and 95% confidence intervals estimated by logistic regression.