Anastrozole and ZD1839 Compared With Fulvestrant and ZD1839 in Postmenopausal Women w/ Metastatic Breast Cancer

This randomized phase II trial is studying how well giving gefitinib together with anastrozole works compared to giving gefitinib together with fulvestrant in treating postmenopausal women with recurrent or metastatic breast cancer. Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using anastrozole and fulvestrant may fight breast cancer by blocking the use of estrogen. Gefitinib (ZD1839) may stop the growth of cancer cells by blocking the enzymes necessary for their growth. It is not yet known whether gefitinib is more effective when combined with anastrozole or fulvestrant in treating breast cancer.