Beliefs about medication and uptake of preventive therapy in women at increased risk of breast cancer: Results from a multi-centre prospective study - Abstract only

Background: The effectiveness of preventive therapy for breast cancer depends on adequate uptake, but initiation rates remain low. Little is known about factors influencing the decision to use chemoprevention. We examined whether women at increased risk of breast cancer can be categorised into groups with similar medication beliefs and evaluated whether belief group membership was associated with uptake. Method: Women (n = 732) attending an appointment at one of 20 centres in England to discuss breast cancer risk were approached; 55.7% (408/732) completed a survey containing the Beliefs about Medicines Questionnaire (BMQ) and the Perceived Sensitivity to Medicines (PSM) scale. Self-reported uptake of tamoxifen at 3-month follow-up was reported in 258 (63.2%). The optimal number of medication belief groups was identified using Latent Profile Analysis (LPA). Results: Among baseline respondents (mean age = 45.3 years, SD = 7.8), 59.6% were at moderately high risk of breast cancer (17-30% lifetime risk) and 39.0% were at high risk of breast cancer (≥30% lifetime risk). Uptake of tamoxifen was 14.7% (38/258). The LPA model supported a 2-group model. Both groups held weak beliefs about their perceived need for tamoxifen. Group 2 (38% of the sample) reported stronger concerns about tamoxifen and medicines in general, and stronger perceived sensitivity to the negative effects of medicines compared with Group 1 (62%). Women with low necessity and lower concerns (Group 1) were more likely to initiate tamoxifen (18.3%; 33) than those with low necessity and higher concerns (Group 2) (6.4%; 5). After adjusting for demographic and clinical factors, the OR was 3.37 (95% confidence interval: 1.08 – 10.51, p = .036). Conclusion: Uptake of breast cancer preventive therapy was low. An important sub-group of women reported low need for preventive therapy and strong medication concerns. These women were less likely to initiate tamoxifen. Medication beliefs are modifiable targets to support informed treatment decision-making. Disclosure: SGS was supported by a Cancer Research UK postdoctoral fellowship (C42785/A17965) during the collection of these data. He also acknowledges funding support from a Yorkshire Cancer Research University Academic Fellowship.