Renehan et al (2004) reported a relative risk of premenopausal breast cancer between the top and bottom quartile of IGF-1 of 2.08 (1.37–3.15), with no significant associations for postmenopausal breast cancer. Lukanova et al (2002, 2004) reported a nonsignificant positive association between IGF-1and premenopausal ovarian cancer (RR=1.90 (0.63–5.75)) with no other associations approaching statistical significance. This evidence concerns the gene IGF1 and breast cancer.