Mammographic density change in a cohort of premenopausal women receiving tamoxifen for breast cancer prevention over 5 years

Table 3 Number of women with a decrease in breast density greater than a cutpoint using analysis sample C (women with density change measured at 1 year and 2 years)

	Cutpoint*	Cutpoint*	Tamoxifen			No tamoxifen			Decrease
Measure	no change	change	No change	Intermediate	Decrease	No change	Intermediate	Decrease	difference (95% CI)
(a) Visual %
T1–T0	0.0	−10.0	24 (34%)	20 (29%)	26 (37%)	57 (64%)	18 (20%)	14 (16%)	21% (7–36%)
(b) Stratus %
T1–T0	0.0	−4.6	10 (14%)	16 (23%)	44 (63%)	45 (51%)	30 (34%)	14 (16%)	47% (32–62%)
T2–T0	0.0	−4.6	9 (13%)	14 (20%)	47 (67%)	50 (56%)	20 (22%)	19 (21%)	46% (31–61%)
(c) Densitas %
T1–T0	0.0	−3.6	9 (13%)	17 (24%)	44 (63%)	48 (54%)	27 (30%)	14 (16%)	47% (32–62%)
T2–T0	0.0	−3.6	7 (10%)	23 (33%)	40 (57%)	47 (53%)	24 (27%)	18 (20%)	37% (21–52%)
(d) Volpara %
T1–T0	0.0	−1.4	14 (20%)	17 (24%)	39 (56%)	45 (51%)	30 (34%)	14 (16%)	40% (25–55%)
T2–T0	0.0	−1.4	5 (7%)	19 (27%)	46 (66%)	48 (54%)	22 (25%)	19 (21%)	44% (29–60%)
(e) NNVAS %
T1–T0	0.0	−4.4	8 (11%)	24 (34%)	38 (54%)	36 (40%)	39 (44%)	14 (16%)	39% (23–54%)
T2–T0	0.0	−4.4	10 (14%)	14 (20%)	46 (66%)	47 (53%)	29 (33%)	13 (15%)	51% (37–66%)

T0, density at entry; T1, density at 1 year; T2, density at 2 year; no change, density change greater than or equal to this is classed as no change; change, density change less than or equal to this is classed as decrease; the intermediate category is density in between these; decrease difference, absolute difference in density change percentage between tamoxifen and no tamoxifen groups
^*For automated methods, the cutpoints shown are for differences in transformed percentage density (×10), being the natural logarithm for Volpara and square root for the other methods.

ISSN: 1465-542X