IGF1 and breast carcinoma: None of these adjustments altered the OR for IGF1 and breast cancer by more than 2% (data not shown) with the exception of adjustment for testosterone in postmenopausal women, which reduced the OR for an 80 percentile difference in IGF1 from 1·30 (95% CI 1·08–1·55) to 1·24 (1·04–1·49).