Polymorphisms in genes involved in estrogen and progesterone metabolism and mammographic density changes in women randomized to postmenopausal hormone therapy: results from a pilot study

Table 2 Change in mammographic percentage density by treatment assignment

Treatment	Change in mammographic density (%)
	Unadjusted mean ± SEM	P	Adjusted mean ± SEM*	P
EPAT
Placebo (n = 57)	- 0.7 ± 0.8	Ref.	- 0.9 ± 0.9	Ref.
ET (n = 70)	3.4 ± 0.7	0.003	4.0 ± 0.8	0.0001
WELL-HART
Placebo (n = 37)	0.8 ± 1.4	Ref.	0.06 ± 1.7	Ref.
ET (n = 34)	4.8 ± 1.5	0.06	5.6 ± 1.5	0.02
EPT (n = 34)	7.8 ± 1.5	0.001	7.8 ± 1.6	0.0005
P homogeneity of treatment effect between trials				0.76
All women
Placebo (n = 95)	- 0.02 ± 0.8	Ref.	0.02 ± 0.8	Ref.
ET (n = 104)	3.9 ± 0.7	0.0003	4.6 ± 0.8	0.0001
EPT (n = 34)	7.8 ± 1.3	0.0001	7.2 ± 1.5	0.0001

*Adjusted for mammographic percentage density at baseline, race, age at baseline, years since menopause, past use of hormone therapy, body mass index (BMI) at baseline, change in BMI on trial and study group. EPAT, Estrogen in the Prevention of Atherosclerosis Trial; EPT, estrogen and progestin therapy; ET, estrogen therapy; WELL-HART, Women's Estrogen–Progestin Lipid-Lowering Hormone Atherosclerosis Regression Trial.

ISSN: 1465-542X