Circulating insulin-like growth factor-I, insulin-like growth factor binding protein-3 and terminal duct lobular unit involution of the breast: a cross-sectional study of women with benign breast disease

Table 2 Distribution of IGF levels and TDLU characteristics among women with benign breast disease, stratified by menopausal status

	All women (n = 228)				Premenopausal (n = 155)				Postmenopausal (n = 73)
	Median	Range	Correlation with density, r	Adj. correlation with density, r	Median	Range	Correlation with density, r	Adj. correlation with density, r	Median	Range	Correlation with density, r	Adj. correlation with density, r	P value^a
IGF measures
IGF-I (ng/ml)	116.15	20.68–250.85	0.08	−0.11	119.4	55.69–250.85	0.0001	−0.11	110.87	20.68–213.43	−0.05	−0.09	0.001
IGFBP-3 (ng/ml)	3451.25	1165.0–4926.5	−0.22^**	−0.14^*	3419.5	1784.5–4926.5	−0.25^**	−0.13	3467	1165.0–4878.5	−0.18	−0.12	0.44
IGF-I:IGFBP-3 Molar ratio	0.122	0.062–0.268	0.27^**	−0.03	0.13	0.071–0.074	0.20^*	−0.05	0.11	0.062–0.189	0.08	−0.01	0.0001
Lobular involution Measures
TDLU count^b	4	0–100	0.22^*	0.02	5	0–100	0.21*	0.005	3	0–79	0.14	0.02	0.16
Median TDLU span, μm	266	78–1030	0.17*	0.08	292	78–1030	0.14	0.08	202	83–568	−0.17	−0.001	0.0001
Median category of acini counts per TDLU	1	1–6	0.09	0.03	1	1–6	0.11	0.04	1	1–5	−0.10	−0.008	0.35

Correlation between insulin-like growth factor (IGF) and involution measures (continuous) with percent volumetric mammographic density was calculated using Spearman partial rank-order correlation. Adjusted (Adj.) correlation was calculated after removing the effects of age and body mass index. *P <0.05, **P <0.001. ^a P values comparing levels of IGFs for premenopausal and postmenopausal women were calculated using Kruskal–Wallis rank test. ^bTerminal duct lobular unit (TDLU) count refers to numbers of TDLUs per unit of tissue area. r Spearman rho, IGFBP-3 insulin-like growth factor binding protein-3

ISSN: 1465-542X