Mammographic density defined by higher than conventional brightness threshold better predicts breast cancer risk for full-field digital mammograms

Table 2 Breast cancer risk association (OPERA) for the mammographic measurements after adjusted for age, body mass index, menopausal status and machine (Hologic and General Electric)

	Cases	OR^a	95 % CI^b	P ^c	AUC^d (95 % CI)	LL
Cumulus
Dense area
Q1^e (n = 211)	47	1.00	−	−
Q2^e (n = 211)	54	1.18	0.76−1.84	0.5
Q3^e (n = 211)	53	1.17	0.74−1.84	0.5
Q4^e (n = 210)	59	1.37	0.88−2.14	0.2
OPERA	213	1.18	1.01−1.39	0.03	0.55 (0.51−0.59)	-290.1865
Percent density
Q1	49	1.00	−	−
Q2	49	0.98	0.63−1.54	0.9
Q3	53	1.09	0.70−1.71	0.7
Q4	62	1.4	0.90−2.17	0.1
OPERA	213	1.23	1.05−1.44	0.01	0.56 (0.52−0.61)	-289.0511
Altocumulus
Dense area
Q1	43	1.00	−	−
Q2	55	1.46	0.91−2.34	0.1
Q3	52	1.38	0.85−2.22	0.2
Q4	63	1.84	1.13−2.99	0.01
OPERA		1.36	1.15−1.62	<0.001	0.59 (0.55−0.63)	-285.9140
Percentage density
Q1	42	1.00	−	−
Q2	54	1.49	0.92−2.39	0.1
Q3	44	1.16	0.70−1.92	0.6
Q4	73	2.49	1.52−4.09	<0.001
OPERA	213	1.41	1.19−1.68	<0.001	0.60 (0.56−0.65)	-284.7104
Cirrocumulus
Dense area
Q1	41	1.00	−	−
Q2	58	1.61	1.01−2.58	0.05
Q3	53	1.42	0.89−2.26	0.1
Q4	61	1.78	1.11−2.86	0.02
OPERA	213	1.23	1.04−1.45	0.01	0.57 (0.52−0.61)	-289.3243
Percentage density
Q1	49	1.00	−	−
Q2	51	1.06	0.67−1.67	0.8
Q3	52	1.09	0.70−1.69	0.7
Q4	61	1.40	0.89−2.22	0.1
OPERA	213	1.21	1.03−1.42	0.02	0.56 (0.52−0.61)	-289.6855

OPERA Odds PER Adjusted standard deviation, LL log likelihood
^aOdds ratio per standard deviation of the risk factors adjusted for age, body mass index (BMI), menopausal status and machine (Hologic and General Electric)
^bCI = confidence interval
^c P refers to statistical significance of the odds ratio (OR) estimate
^dAUCs refer to the area under the receiver operating characteristic curves for mammographic measurements after adjusted for age, body mass index, menopausal status and machine (Hologic and General Electric)
^eQuartiles (Q1-Q4) defined by distribution of the measure adjusted for age, body mass index, menopausal status and machine (Hologic and General Electric)

ISSN: 1465-542X