Comparison of the association of mammographic density and clinical factors with ductal carcinoma in situ versus invasive ductal breast cancer in Korean women

Table 2 Multivariable adjusted associations of clinical and reproductive characteristics with invasive ductal carcinoma and ductal carcinoma in situ

	Invasive ductal cancer				Ductal carcinoma in situ				P ^‡ for interaction
	Measurement*		Association		Measurement*		Association
Variables	Cases (n = 472)	Controls (n = 912)	OR (95% CI)^†	P value	Cases (n = 90)	Controls (n = 176)	OR (95% CI)^†	P value
Body mass index, increase by 1 kg/m²	23.1 (3.0)	22.5 (2.8)	1.01 (0.98,1.04)	0.581	21.8 (2.4)	22.1 (2.8)	0.94 (0.86,1.03)	0.210	0.259
Age at menarche, increase by 1- year	14.6 (1.7)	14.9 (1.6)	0.94 (0.88,0.99)	0.030	14.8 (1.7)	14.8 (1.5)	1.08 (0.92,1.26)	0.370	0.320
Number of live birth, increase by 1-person	1.9 (0.9)	2.1 (1.0)	0.94 (0.85,1.03)	0.180	1.8 (1.0)	2.0 (1.0)	0.89 (0.71,1.11)	0.304	0.781
Ever-use of estrogen replacement	36 (7.6)	96 (10.5)	0.88 (0.59,1.30)	0.515	4 (4.4)	11 (6.3)	1.04 (0.31,3.41)	0.955	0.901
Ever alcohol consumption	223(47.3)	349(38.3)	1.19(0.99,1.44)	0.068	48(53.3)	64(36.4)	1.81(1.14,2.89)	0.013	0.105
Ever smoking	40(8.5)	43(4.7)	1.16(0.83,1.63)	0.381	6(6.7)	11(6.3)	0.96(0.37,2.53)	0.934	0.910
Regular physical exercise(≥1/week)	248(52.5)	754(82.8)	0.45(0.37,0.54)	<0.001	51(56.7)	148(84.1)	0.52(0.31,0.87)	0.013	0.434
Previous benign breast disease	49 (10.4)	39 (4.3)	2.31 (1.86,2.86)	<0.001	28 (31.1)	16 (9.1)	2.04 (1.23,3.39)	0.006	0.484
Breast cancer among first degree relatives	127 (26.9)	55 (6.0)	1.43 (1.05,1.95)	0.025	7 (7.8)	3 (1.7)	2.14 (0.84,5.44)	0.109	0.701

*Presented by mean (standard deviation) for continuous variables or number (%) for categorical variables
†Odd ratio (OR) and 95% confidence intervals (CI) were estimated by conditional logistic regression analysis after adjusting for age, menopausal status, height, body mass index, age at menarche, number of children, ever smoking status, alcohol consumption, regular physical exercise, family history of breast cancer among first degree relatives, past history of benign breast disease, use of estrogen replacement, and the method of recruiting subjects
‡Estimated by putting interaction term (each variable X invasiveness) in the conditional logistic regression model with adjustment for covariates

ISSN: 1471-2407