R. Burcombe (QQ, United Kingdom)
Kent Oncology CentreAuthor Of 1 Presentation
142P - Bone mineral density (BMD) after three years of adjuvant zoledronic acid (ZA) in postmenopausal oestrogen receptor positive (ER+) early breast cancer (EBC): an observational single centre study.
Abstract
Background
Adjuvant bisphosphonate therapy is recommended in postmenopausal women with intermediate or high risk EBC. Bisphophonates improve breast cancer outcomes and also protect against bone loss from adjuvant aromatase inhibitors (AI). The increasing use of extended adjuvant AIs beyond 5 years has implications for bone health. There is currently no specific guidance for BMD monitoring in patients on extended endocrine therapy.
Methods
Women with ER+ EBC who had completed 3 years of adjuvant intravenous ZA and continued on adjuvant AI attended for a single DEXA (dual-energy X-ray absorptiometry) to evaluate BMD. DEXA scan T-scores of lumbar spine and neck of femur were recorded; femoral neck scores are presented here. The UK National Cancer Research Institute (NCRI) Breast Cancer Study Group and National Osteoporosis Society management of bone loss in EBC guidelines were used to guide subsequent bone management. BMD was categorised based on T-score: <-2.0, <-1.0 but >-2.0 and >-1.0.
Results
54 patients attended for DEXA scans having completed 3 years of adjuvant ZA. 33 patients (61%) had femoral neck BMD of T >-1.0, 14 (26%) T<-1.0 but >-2.0 and 7 (13%) T<-2.0. 6 patients had a previous DEXA scan documented (for osteoporosis or other reasons). Of these, BMD had improved (4), was unchanged (1) or worsened (1).
Conclusions
It has always been assumed that adjuvant ZA ameliorates AI-induced bone loss. This small study indicates that a significant proportion (39%) of patients have a BMD that requires intervention (osteoporosis treatment or DEXA monitoring) based on the UK EBC BMD monitoring guidelines, after 3 years adjuvant ZA treatment. The use of FRAX (Fracture Risk Assessment Tool) has not been well documented in this cohort; collection of FRAX data in these patients is underway for future analysis. Given the increasing use of extended AI therapy in EBC, a post-ZA BMD DEXA scan after ZA treatment is complete should be considered. Guidelines are required for the management of bone health after adjuvant bisphosphonate therapy, particularly in patients continuing AI treatment.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
C. Harper-wynne: Honoraria (self), Advisory/Consultancy: Pfizer; Honoraria (self), Advisory/Consultancy: Lilly; Honoraria (self), Advisory/Consultancy: Roche; Honoraria (self), Advisory/Consultancy: AstraZeneca; Honoraria (self): Myriad; Honoraria (self), Advisory/Consultancy: Genomic Health; Honoraria (self): Everything Genetic; Honoraria (self): Eisai; Honoraria (self): Novartis. R. Burcombe: Honoraria (self), Advisory/Consultancy: Pfizer; Honoraria (self), Advisory/Consultancy: Novartis; Honoraria (self), Advisory/Consultancy: Lilly; Honoraria (self), Advisory/Consultancy: Roche; Honoraria (self), Advisory/Consultancy: Eisai; Honoraria (self), Advisory/Consultancy: Genomic Health; Honoraria (self), Advisory/Consultancy: Myriad; Honoraria (self), Advisory/Consultancy: Everything Genetic.