Table 2.
Predominant type 1/no type 3 lobules according to batch-specific quartiles of plasma IGF-1
| IGF-1 (ng/ml) | |||||
|---|---|---|---|---|---|
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P value | |
| Predominant type 1, no type 3/other lobule type (n) | (24/93) | (20/98) | (20/98) | (10/109) | |
| Age and batch-adjusteda | 1 (reference) | 0.82 (0.40 to 1.67) | 0.84 (0.41 to 1.76) | 0.37 (0.15 to 0.89) | 0.01 |
| Multivariate model 1b | 1 (reference) | 0.98 (0.46 to 2.07) | 1.06 (0.49 to 2.29) | 0.47 (0.19 to 1.17) | 0.08 |
| Multivariate model 2c | 1 (reference) | 0.94 (0.44 to 2.01) | 1.00 (0.46 to 2.19) | 0.41 (0.16 to 1.04) | 0.05 |
| Multivariate model 3d | 1 (reference) | 0.92 (0.41 to 2.05) | 0.98 (0.41 to 2.31) | 0.39 (0.13 to 1.18) | 0.07 |
Data (vs. other types) from the Nurses' Health Study II presented as odds ratio (95% confidence interval) unless stated otherwise. aAge at biopsy (continuous), insulin-like growth factor 1 (IGF-1) batch. bAge at biopsy (continuous), IGF-1 batch, body mass index (continuous), menopausal status (premenopausal/dubious; postmenopausal, no postmenopausal hormone use; postmenopausal, postmenopausal hormone use), histological category of benign breast disease (proliferative without atypia, proliferative with atypia). cMultivariate model 1 plus parity (nulliparous, parous), alcohol (none, < 1.5, 1.5 to 4.5, 4.5+ g/day). dMultivariate model 2 plus insulin-like growth factor binding protein-3 (continuous).