Table 1.

Comparison of Baseline Fibroglandular Tissue Volume and Percent Breast Density measured by MRI

Group	N	Mean	Standard Deviation	Median	Geometric Mean (ie. ExpMean)	25th Pctl	75th Pctl	Nominal p-value for independent sample t-test1
Outcome variable: Loge(FV (ml) at Baseline)
Pre-menopausal women	29	4.90	0.50	4.84	134.39	4.51	5.35	0.0017
Post-menopausal women	15	4.31	0.64	4.09	74.68	3.89	4.71
ER+ cancer	25	4.68	0.67	4.54	107.71	4.09	5.35	0.7983
ER- cancer	19	4.73	0.55	4.71	113.08	4.51	5.18
Her-2+ cancer	16	4.51	0.63	4.53	91.26	4.01	4.94	0.1181
Her-2 cancer	25	4.82	0.59	4.76	124.58	4.38	5.35
Outcome variable: Loge(PD% at Baseline)
Pre-menopausal women	29	2.69	0.60	2.77	14.68	2.20	3.19	0.0017
Post-menopausal women	15	1.88	0.73	1.80	6.57	1.40	2.28
ER+ cancer	25	2.31	0.84	2.27	10.07	1.63	3.11	0.2984
ER- cancer	19	2.55	0.61	2.41	12.79	1.98	3.11
Her-2+ cancer	16	2.30	0.85	2.10	10.01	1.72	3.08	0.4482
Her-2 cancer	25	2.49	0.73	2.41	12.10	1.88	3.18

Descriptive statistics and p-values for independent sample t-tests tests are presented.

¹P-values in italic bold type font indicate statistically significant results, adjusted for multiple comparisons.