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

Table 4 Association of %MD categories prior to/at first diagnosis^a and post diagnosis^b with CBC risk by family history^c

	CBC Number (%)	UBC Number (%)	OR^d (95% CI)
Percent mammographic density prior to/at diagnosis
No family history
<25%	44 (27)	64 (31)	0.73 (0.42, 1.27)
25 to <50%	81 (49)	97 (46)	1.00
≥50%	40 (24)	48 (23)	0.96 (0.54, 1.70)
Family history
<25%	22 (26)	16 (29)	0.95 (0.32, 2.86)
25 to <50%	43 (51)	30 (55)	1.00
≥50%	20 (24)	9 (16)	2.19 (0.62, 7.73)
p interaction			0.50
Post diagnosis
No family history
<25%	86 (39)	132 (46)	0.76 (0.50, 1.15)
25 to <50%	102 (47)	124 (44)	1.00
≥50%	30 (14)	28 (10)	1.28 (0.69, 2.36)
Family history
<25%	41 (37)	46 (53)	0.53 (0.25, 1.14)
25 to <50%	47 (43)	28 (33)	1.00
≥50%	22 (20)	12 (14)	1.55 (0.57, 4.22)
p interaction			0.59

Abbreviations: %MD percent mammographic density, CBC contralateral breast cancer, UBC unilateral breast cancer, OR odds ratio, CI confidence interval
^aPrior to/at 1st diagnosis was 36 months prior up to 1 month post diagnosis
^bPost diagnosis was > 6 months up to 48 months post diagnosis
^cFamily history is defined as having a first-degree relative (mother, sister, daughter) with breast cancer, women with unknown family history were excluded.
^dOR 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, histologic type, stage, and estrogen receptor status of first diagnosis, chemotherapy, radiation, and tamoxifen use after first diagnosis

ISSN: 1465-542X