The association of mammographic density with risk of contralateral breast cancer and change in density with treatment in the WECARE study

Table 2 Association between %MD and CBC risk categories prior to/at^a diagnosis and post diagnosis^b

	CBC Number (%)	UBC Number (%)	OR^c (95% CI)
Percent mammographic density prior to/at diagnosis
<25%	67 (26)	81 (30)	0.77 (0.49, 1.21)
25 to <50%	125 (49)	130 (48)	1.00
≥50%	61 (24)	58 (22)	1.17 (0.73, 1.87)
p trend			0.12
Percent mammographic density post diagnosis
<25%	129 (39)	181 (48)	0.69 (0.49, 0.98)
25 to <50%	152 (46)	155 (41)	1.00
≥50%	52 (16)	41 (11)	1.21 (0.74, 1.99)
p trend			0.03

Abbreviations: %MD percent mammographic density, CBC contralateral breast cancer, UBC unilateral breast cancer, OR odds ratio, CI confidence interval
^aPior to/at diagnosis was 36 months prior up to 1 month post diagnosis
^bPost diagnosis was > 6 months up to 48 months post diagnosis
^cOR adjusted for study center, race (non-Hispanic white versus other), age at mammogram, menopausal status at mammogram, estimated body mass index at mammogram, age at first diagnosis, age at menarche, number of full-term pregnancies, first-degree family history of breast cancer, histologic type, stage, estrogen receptor status of first diagnosis, chemotherapy, radiation, and tamoxifen use after first diagnosis

ISSN: 1465-542X