Early participant-reported symptoms as predictors of adherence to anastrozole in the International Breast Cancer Intervention Studies II

Gandhi

et al. 2020

Cancers

Clinics for women concerned about their family history of breast cancer are widely established. A Family History Clinic was set-up in Manchester, UK, in 1987 in a Breast Unit serving a population of 1.8 million. In this review, we report the outcome of risk assessment, screening and prevention strategies in the clinic and propose future approaches. Between 1987–2020, 14,311 women were referred, of whom 6.4% were from known gene families, 38.2% were at high risk (≥30% lifetime risk), 37.7% at moderate risk (17–29%), and 17.7% at an average/population risk who were discharged. A total of 4168 (29.1%) women were eligible for genetic testing and 736 carried pathogenic variants, predominantly in BRCA1 and BRCA2 but also other genes (5.1% of direct referrals). All women at high or moderate risk were offered annual mammographic screening between ages 30 and 40 years old: 646 cancers were detected in women at high and moderate risk (5.5%) with a detection rate of 5 per 1000 screens. Incident breast cancers were largely of good prognosis and resulted in a predicted survival advantage. All high/moderate-risk women were offered lifestyle prevention advice and 14–27% entered various lifestyle studies. From 1992–2003, women were offered entry into IBIS-I (tamoxifen) and IBIS-II (anastrozole) trials (12.5% of invitees joined). The NICE guidelines ratified the use of tamoxifen and raloxifene (2013) and subsequently anastrozole (2017) for prevention; 10.8% women took up the offer of such treatment between 2013–2020. Since 1994, 7164 eligible women at ≥25% lifetime risk of breast cancer were offered a discussion of risk-reducing breast surgery and 451 (6.2%) had surgery. New approaches in all aspects of the service are needed to build on these results.

Section: Chemopreventionsupporting

confidence: 89%

Long-Term Evaluation of Women Referred to a Breast Cancer Family History Clinic (Manchester UK 1987–2020)

Gandhi

et al. 2020

Cancers

Breast Cancer Res Treat

“…However, the lack of relationship between weight and preventive therapy adherence suggests that this is unlikely to be a major factor [40,41]. Our analysis was on an intention-to-treat basis, and therefore, the small differences in medication adherence between the treatment and control groups may have affected our effect estimates [42,43]. Weight gain has been observed among women using preventive therapy; however, a previous report using the IBIS cohorts indicated that this generally occurred in the first 12 months of participation and was similar among treatment and placebo arms [44].…”

Section: Discussionmentioning

confidence: 99%

The impact of body mass index on breast cancer incidence among women at increased risk: an observational study from the International Breast Intervention Studies

Smith

Šestak

Morris

et al. 2021

Background We investigated the association between body mass index (BMI) and breast cancer risk in women at increased risk of breast cancer receiving tamoxifen or anastrozole compared with placebo using data from the International Breast Cancer Intervention Studies [IBIS-I (tamoxifen) and IBIS-II (anastrozole)]. Methods Baseline BMI was calculated from nurse assessed height and weight measurements for premenopausal (n = 3138) and postmenopausal (n = 3731) women in IBIS-I and postmenopausal women in IBIS-II (n = 3787). The primary endpoint was any breast cancer event (invasive and ductal carcinoma in situ). We used Cox proportional hazards regression to calculate hazard ratios (HRs) for risk after adjustment for covariates. Results There were 582 (IBIS-I) and 248 (IBIS-II) breast cancer events [median follow-up = 16.2 years (IQR 14.4–17.7) and 10.9 years (IQR 8.8–13.0), respectively]. In adjusted analysis, women with a higher BMI had an increased breast cancer risk in both IBIS-I [HR = 1.06 per 5 kg/m2 (0.99–1.15), p = 0.114] and in IBIS-II [HR per 5 kg/m2 = 1.21 (1.09–1.35), p < 0.001]. In IBIS-I, the association between BMI and breast cancer risk was positive in postmenopausal women [adjusted HR per 5 kg/m2 = 1.14 (1.03–1.26), p = 0.01] but not premenopausal women [adjusted HR per 5 kg/m2 = 0.97 (0.86–1.09), p = 0.628]. There was no interaction between BMI and treatment group for breast cancer risk in either IBIS-I (p = 0.62) or IBIS-II (p = 0.55). Conclusions Higher BMI is associated with greater breast cancer risk in postmenopausal women at increased risk of the disease, but no effect was observed in premenopausal women. The lack of interaction between BMI and treatment group on breast cancer risk suggests women are likely to experience benefit from preventive therapy regardless of their BMI. Trial registration Both trials were registered [IBIS-I: ISRCTN91879928 on 24/02/2006, retrospectively registered (http://www.isrctn.com/ISRCTN91879928); IBIS-II: ISRCTN31488319 on 07/01/2005, retrospectively registered (http://www.isrctn.com/ISRCTN31488319)]

Breast Cancer Res Treat

“…Optimal therapeutic benefit depends on adequate uptake and adherence to the recommended course of therapy. However, uptake can be low and long-term persistence problematic [ 6 – 8 ].…”

Section: Introductionmentioning

confidence: 99%

Uptake of breast cancer preventive therapy in the UK: results from a multicentre prospective survey and qualitative interviews

Hackett

Thorneloe

Side

et al. 2018

PurposeUptake of preventive therapy for women at increased breast cancer risk in England is unknown following the introduction of UK clinical guidelines in 2013. Preventive therapy could create socioeconomic inequalities in cancer incidence if it is more readily accepted by particular socio-demographic groups. In this multicentre study, we investigated uptake of tamoxifen and evaluated socio-demographic and clinical factors associated with initiation. We explored women’s experiences of treatment decision-making using qualitative interview data.MethodsBetween September 2015 and December 2016, women (n = 732) attending an appointment at one of 20 centres in England to discuss breast cancer risk were approached to complete a survey containing socio-demographic details and nulliparity. Of the baseline survey respondents (n = 408/732, 55.7% response rate), self-reported uptake of tamoxifen at 3-month follow-up was reported in 258 (63.2%). Sixteen women participated in semi-structured interviews.ResultsOne in seven (38/258 = 14.7%) women initiated tamoxifen. Women who had children were more likely to report use of tamoxifen than those without children (OR = 5.26; 95%CI: 1.13–24.49, p = 0.035). Interview data suggested that women weigh up risks and benefits of tamoxifen within the context of familial commitments, with exposure to significant other’s beliefs and experiences of cancer and medication a basis for their decision.ConclusionsUptake of tamoxifen is low in clinical practice. There were no socio-demographic differences in uptake, suggesting that the introduction of breast cancer preventive therapy is unlikely to create socioeconomic inequalities in cancer incidence. Women’s decision-making was influenced by familial priorities, particularly having children.Electronic supplementary materialThe online version of this article (10.1007/s10549-018-4775-1) contains supplementary material, which is available to authorized users.