Table 1.

Table 1a. Association between BRCA1 promoter methylation and potential predictors of breast cancer survival assessed at the baseline interview (N=851)¹

Table 1b. Association between BRCA1 promoter methylation and potential predictors of breast cancer survival assessed at the baseline interview

Feature	BRCA1 methylated, n=504 (59.2)	BRCA1 unmethylated, n=347 (40.8)	p-value
Age at diagnosis (y)
≤60	259(59.7)	175(40.3)	0.78
>60	245(58.8)	172(41.2)
mean age	59.0	60.4	0.12 (t-test)
Race	n=503	n=346
White	463(58.5)	329(41.5)	0.21
Black	29(69.0)	13(31.0)
Other	11(73.3)	4(26.7)
Cancer type	n=504	n=347
in situ	51(49.0)	53(51.0)	0.024
invasive	453(60.6)	294(39.4)
Menopausal status	n=493	n=340
pre-	157(64.3)	87(35.7)	0.051
post-	336(57.0)	253(43.0)
Family history	n=488	n=333
no	399(59.9)	267(40.1)	0.570
yes	89(57.4)	66(42.6)
History of benign breast disease	n=503	n=347
no	417(60.2)	276(39.8)	0.214
yes	86(54.8)	71(45.2)
Supplement use2	n=498	n=341
no	262(60.0)	175(40.0)	0.713
yes	236(58.7)	166(41.3)
Active smoking	n=504	n=347
never	229(60.6)	149(39.4)	0.192
current	88(53.0)	78(47.0)
past/former	187(60.9)	120(39.1)
Passive smoking	n=491	n=340
never	95(58.6)	67(41.4)	0.397
current	73(54.1)	62(45.9)
past/former	323(60.5)	211(39.5)
Folate intake (ug/day)	n=498	n=341
mean (dietary)	264.9	258.7	0.52(t-test)
mean (total)	443.8	450.1	0.79(t-test)
Feature	BRCA1 methylated, n=504 (59.2)	BRCA1 unmethylated, n=347 (40.8)	p-value
ER status	n=372	n=253
negative	89(59.7)	60(40.3)	0.952
positive	283(59.4)	193(40.6)
PR status	n=372	n=253
negative	135(59.2)	93(40.8)	0.905
positive	237(59.7)	160(40.3)
Node	n=202	n=125
0	142(57.3)	106(42.7)	0.003
1+	60(76.0)	19(24.0)
Tumor size	n=199	n=122
≤ 2cm	141(57.1)	106(42.9)	0.003
2cm-5cm	52(78.8)	14(21.2)
>5cm	6(75.0)	2(25.0)

¹Numbers in the parenthesis are percentages of methylated or unmethylated case in each category.

²Supplement: multivitamin supplement use in the 5 years prior to the baseline interview.

^*Fisher's Exact Test