General Practitioner attitudes towards prescribing tamoxifen for the primary prevention of breast cancer: results of a vignette study


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Samuel Smith1,Robbie Foy2,Jennifer McGowan3,Lindsay Kobayashi3,Karen Brown4,Lucy Side3,Jack Cuzick1
1Queen Mary University of London,2University of Leeds,3University College London,4University of Leicester



A key recommendation of the Independent Cancer Taskforce was to ensure general practitioners (GPs) are appropriately prescribing tamoxifen for breast cancer primary prevention. We investigated the barriers to prescribing tamoxifen for chemoprevention among GPs in the NHS.


We conducted an online survey of GPs in England, Northern Ireland and Wales in 2016 (N=928). Respondents were randomised to read one of four vignettes (1:1:1:1) describing a healthy patient seeking a tamoxifen prescription. Using a 2x2 between-subjects design, the patient’s breast cancer risk (‘moderate risk’ vs. ‘high risk’) and the clinician responsible for initiating the prescription (‘GP prescriber’ vs. ‘secondary care clinician [SCC] prescriber’) were manipulated. Outcomes were willingness to prescribe, comfort discussing harms and benefits, comfort managing the patient, factors affecting the prescribing decision, and awareness of tamoxifen and NICE guidelines (CG164).


Half (51.7%) of the GPs knew that tamoxifen can reduce breast cancer risk; a quarter (24.1%) were aware of relevant NICE guidelines. Respondents who were asked to initiate prescribing (‘GP prescriber’) were less willing to prescribe tamoxifen than those who were asked to take over the prescribing role from secondary care (‘SCC prescriber’) (68.9% vs. 84.6%, p<0.001). The GP prescribers also reported less comfort discussing tamoxifen with the patient (53.4% vs. 62.5%, p=0.005). There were no differences in comfort managing the patient between GP and SCC prescribers. No differences were apparent for any outcome between the breast cancer risk groups. Compared with respondents unwilling to prescribe, GPs willing to prescribe were more likely to consider the benefits of tamoxifen (87.6% vs. 97.2%, p<0.001) and less likely to consider its ‘off-licence’ status (91.4% vs. 69.6%, p<0.001).


There is low awareness among GPs of tamoxifen as a preventive agent. A shared care agreement between primary and secondary care may overcome reluctance from GPs to initiate tamoxifen prescriptions.