PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 11396362-2 2001 The third-generation aromatase inhibitors have replaced megestrol acetate as second-line hormonal therapy in advanced breast cancer, and large clinical trials are maturing to establish their efficacy relative to tamoxifen (Nolvadex) in the first-line metastatic setting. Megestrol Acetate 56-73 cytochrome P450 family 19 subfamily A member 1 Homo sapiens 21-30