Variation in bone health management in older women with breast cancer: A secondary analysis of the Age Gap study

Abstract

Introduction: Physiological age-related bone loss is common, with 50% of women aged ≥80 having osteoporosis. Bone loss is exacerbated in women receiving aromatase inhibitors (AIs) for early breast cancer (EBC), increasing fracture risk. This study explored the management of bone-health in older women (≥70 years) with EBC and factors influencing clinical decision-making.

Materials and methods: This was a sub-study of a larger United Kingdom multicentre observational study into practice variation and outcomes in older women (≥70) with EBC (Age Gap study). Participants were aged ≥70 years with EBC; data were collected on health status, treatments, and outcomes. This sub-study focused on patients recruited at five hospitals, where more detailed data on bone health and management were collected for women with ER + ve (oestrogen receptor positive) cancers who received adjuvant or primary endocrine therapy treatment. We aimed to determine factors influencing treatment selection and outcomes in this age group.

Results: The main Age Gap study recruited between 2013 and 2018. In this sub-study, 565 patients had ER + ve cancers, of whom 529 (93.6%) received AIs and 26 (4.6%) tamoxifen. The median age of participants was 77 years (70-98 years). A baseline dual energy x-ray absorptiometry (DEXA) scan was performed in only 354/529 (67%) of the AI group. Bisphosphonates were prescribed for 226/529 (43%). Baseline DEXA scans were more likely to be requested if patients were fit for surgery and were < 80 years old. Of those scanned (n = 354), 148 (42%) were osteopenic and 64 (18%) osteoporotic. Bisphosphonate prescription was associated with younger age (<80 years old) (p = 0.02). From recruitment to 2022, fractures were diagnosed in 23% of participants (122/529), of whom only 38% (46/122) had received prior bisphosphonates. Frailty or prefrailty (Rockwood scale) were present in 94% (431/461), but there was no correlation between frailty and baseline hip (r² = 0.0098) or spine (r² = 0.00007) T-scores. Rates of DEXA scanning varied between centres from 36% to 76% (p < 0.001) for unknown reasons.

Discussion: Age and general health influenced bone-health management decision-making, but there was considerable variation between centres, highlighting the need for standardised bone-health care for older women with EBC.

Keywords: Aromatase inhibitors; Bisphosphonates; Bone health; Breast cancer; DEXA; Older age.