title: Risk of breast cancer among users of estrogen plus progestogen and unopposed estrogen: is the likelihood of bias symmetrical?
authors: Department of Public Health and Family Medicine, University of Cape Town Faculty of Health Sciences , Cape Town , South Africa.
authors: S
authors: S
authors: Shapiro
mesh_terms: D015982:Bias; D001943:Breast Neoplasms / Q000453:epidemiology*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D017698:Postmenopause; D011372:Progestins / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
chemical_list: D004967:Estrogens; D011372:Progestins
keywords: BREAST CANCER RISK; DETECTION BIAS; HORMONE REPLACEMENT THERAPY; RELATIVE RISK