Mammographic density change in a cohort of premenopausal women receiving tamoxifen for breast cancer prevention over 5 years.

BACKGROUND: A decrease in breast density due to tamoxifen preventive therapy might indicate greater benefit from the drug. It is not known whether mammographic density continues to decline after 1 year of therapy, or whether measures of breast density change are sufficiently stable for personalised recommendations. METHODS: Mammographic density was measured annually over up to 5 years in premenopausal women with no previous diagnosis of breast cancer but at increased risk of breast cancer attending a family-history clinic in Manchester, UK (baseline 2010-2013). Tamoxifen (20 mg/day) for prevention was prescribed for up to 5 years in one group; the other group did not receive tamoxifen and were matched by age. Fully automatic methods were used on mammograms over the 5-year follow-up: three area-based measures (NN-VAS, Stratus, Densitas) and one volumetric (Volpara). Additionally, percentage breast density at baseline and first follow-up mammograms was measured visually. The size of density declines at the first follow-up mammogram and thereafter was estimated using a linear mixed model adjusted for age and body mass index. The stability of density change at 1 year was assessed by evaluating mean squared error loss from predictions based on individual or mean density change at 1 year. RESULTS: Analysis used mammograms from 126 healthy premenopausal women before and as they received tamoxifen for prevention (median age 42 years) and 172 matched controls (median age 41 years), with median 3 years follow-up. There was a strong correlation between percentage density measures used on the same mammogram in both the tamoxifen and no tamoxifen groups (all correlation coeficients > 0.8). Tamoxifen reduced mean breast density in year 1 by approximately 17-25% of the inter-quartile range of four automated percentage density measures at baseline, and from year 2, it decreased further by approximately 2-7% per year. Predicting change at 2 years using individual change at 1 year was approximately 60-300% worse than using mean change at 1year. CONCLUSIONS: All measures showed a consistent and large average tamoxifen-induced change in density over the first year, and a continued decline thereafter. However, these measures of density change at 1 year were not stable on an individual basis.

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

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.

Lifestyle behaviours and health measures of women at increased risk of breast cancer taking chemoprevention.

Women at increased breast cancer (BC) risk are eligible for chemoprevention. Healthy lifestyles are potentially important for these women to improve efficacy and minimise side effects of chemoprevention and reduce the risk of BC and other lifestyle-related conditions. We investigated whether women taking chemoprevention adhere to healthy lifestyle recommendations, how their lifestyle risk factors and health measures compare to women in the general population, and whether these change whilst taking chemoprevention. Lifestyle risk factors and health measures in 136 premenopausal women taking tamoxifen for prevention of BC (Tam-Prev study) were compared to both national recommendations and an age-matched female population from the Health Survey for England 2012. The Tam-Prev population had high rates of overweight and obesity (59.2%) and low adherence to physical activity recommendations (30.6%) which were comparable to the general population (55.2 and 35.1%, respectively). Fewer Tam-Prev participants were current smokers (10.5 vs. 18.2%, P = 0.032), but more exceeded alcohol recommendations (45.0 vs. 18.7%, P < 0.001). Tam-Prev participants had suboptimal diets; proportions not meeting fibre, saturated fat and non-milk extrinsic sugar recommendations were 87.8, 64.9 and 21.4% respectively. Many Tam-Prev participants had markers of cardiovascular disease risk and the metabolic syndrome. Health behaviours did not change during the first year on tamoxifen. Women taking chemoprevention had a high prevalence of unhealthy lifestyle behaviours and health measures, similar to an age-matched English cohort. Improving these measures in women at increased BC risk could significantly decrease rates of BC and other noncommunicable diseases.