title: Prescribing tamoxifen in primary care for the prevention of breast cancer: a national online survey of GPs' attitudes.
abstract: The cancer strategy for England (2015-2020) recommends GPs prescribe tamoxifen for breast cancer primary prevention among women at increased risk.
  
  
  
  To investigate GPs' attitudes towards prescribing tamoxifen.
  
  
  
  In an online survey, GPs in England, Northern Ireland, and Wales (n= 928) were randomised using a 2 × 2 between-subjects design to read one of four vignettes describing a healthy patient seeking a tamoxifen prescription.
  
  
  
  In the vignette, the hypothetical patient's breast cancer risk (moderate versus high) and the clinician initiating the prescription (GP prescriber versus secondary care clinician [SCC] prescriber) were manipulated in a 1:1:1:1 ratio. Outcomes were willingness to prescribe, comfort discussing harms and benefits, comfort managing the patient, factors affecting the prescribing decision, and awareness of tamoxifen and the National Institute for Health and Care Excellence (NICE) guideline CG164.
  
  
  
  Half (51.7%) of the GPs knew tamoxifen can reduce breast cancer risk, and one-quarter (24.1%) were aware of NICE guideline CG164. Responders asked to initiate prescribing (GP prescriber) were less willing to prescribe tamoxifen than those continuing a prescription initiated in secondary care (SCC prescriber) (68.9% versus 84.6%,P<0.001). The GP prescribers reported less comfort discussing tamoxifen (53.4% versus 62.5%,P= 0.01). GPs willing to prescribe were more likely to be aware of the NICE guideline (P= 0.039) and to have acknowledged the benefits of tamoxifen (P<0.001), and were less likely to have considered its off-licence status (P<0.001).
  
  
  
  Initiating tamoxifen prescriptions for preventive therapy in secondary care before asking GPs to continue the patient's care may overcome some prescribing barriers.
authors.affiliation: Institute of Health Sciences, University of Leeds, Leeds, and Wolfson Institute of Preventive Medicine, Queen Mary University of London, London.
authors.forename: Samuel G
authors.initials: SG
authors.lastname: Smith
authors.affiliation: Institute of Health Sciences, University of Leeds, Leeds.
authors.forename: Robbie
authors.initials: R
authors.lastname: Foy
authors.affiliation: Institute of Epidemiology and Healthcare; Institute for Women's Health, University College London, London.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: McGowan
authors.affiliation: Center for Population and Development Studies, Harvard TH Chan School of Public Health, Harvard University, Cambridge, MA.
authors.forename: Lindsay C
authors.initials: LC
authors.lastname: Kobayashi
authors.forename: Andrea
authors.lastname: de Censi
authors.affiliation: Division of Medical Oncology, Ospedali Galliera, Genoa, and Wolfson Institute of Preventive Medicine, Queen Mary University of London, London.
authors.forename: Andrea
authors.initials: A
authors.lastname: DeCensi
authors.affiliation: Department of Cancer Studies, University of Leicester, Leicester.
authors.forename: Karen
authors.initials: K
authors.lastname: Brown
authors.affiliation: Institute for Women's Health, University College London, London.
authors.forename: Lucy
authors.initials: L
authors.lastname: Side
authors.affiliation: Wolfson Institute of Preventive Medicine, Queen Mary University of London, London.
authors.forename: Jack
authors.initials: J
authors.lastname: Cuzick
mesh_terms: D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001291:Attitude of Health Personnel; D001943:Breast Neoplasms / Q000517:prevention & control*; D018890:Chemoprevention; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011320:Primary Health Care; D011322:Primary Prevention / Q000706:statistics & numerical data; D036301:Qualitative Research; D011897:Random Allocation; D018570:Risk Assessment; D013629:Tamoxifen / Q000627:therapeutic use*; D006113:United Kingdom
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen
keywords: breast cancer; chemoprevention; general practice; preventive therapy; primary care; tamoxifen