CYP19A1 and breast cancer: However, a randomised phase II trial has recently shown that a short 4- to 6-weeks treatment with gefitinib monotherapy or with gefitinib plus the aromatase inhibitor anastrozole in postmenopausal breast cancer patients with ER-positive and EGFR-positive tumours before curative surgery determines PR in 12 out of 22 patients and in 14 out of 28 patients, respectively (Polychronis et al, 2005).