title: Postmenopausal estrogens--opposed, unopposed, or none of the above.
authors.forename: W C
authors.initials: WC
authors.lastname: Willett
authors.forename: G
authors.initials: G
authors.lastname: Colditz
authors.forename: M
authors.initials: M
authors.lastname: Stampfer
mesh_terms: D001943:Breast Neoplasms / Q000453:epidemiology*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D004967:Estrogens / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008593:Menopause; D011372:Progestins / Q000008:administration & dosage / Q000009:adverse effects*; D012306:Risk
chemical_list: D004967:Estrogens; D011372:Progestins