Original Research

Calcified Tissue International

, Volume 88, Issue 3, pp 223-230

Does Anastrozole Affect Bone Resorption Similarly in Early and Late Postmenopausal Women?

  • Diane E. PowellAffiliated withCharles Salt Centre for Human Metabolism, Robert Jones & Agnes Hunt Orthopaedic & District Hospital NHS Trust Email author 
  • , Richard A. CochraneAffiliated withBreast Unit, Wrexham Maelor Hospital
  • , Michael W. J. DavieAffiliated withCharles Salt Centre for Human Metabolism, Robert Jones & Agnes Hunt Orthopaedic & District Hospital NHS Trust

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

The aim of this study was to determine whether the bone-resorption response to anastrozole differed according to initial patient age in postmenopausal women with breast cancer in a cross-sectional study. Second-morning void urines were collected for measurement of urinary cross-linked N-telopeptide of type I collagen (uNTx, corrected for creatinine and log-transformed) from postmenopausal women, 99 with breast cancer on anastrozole (ABC), 88 with newly diagnosed breast cancer (NDBC), and 137 community-dwelling healthy control (HC) women. Bone mineral density (BMD) was also measured at the lumbar spine (LS, L2–L4) and the femoral neck (FN) in the ABC group. uNTx (nanomole bone collagen equivalents/millimole creatinine) levels increased with age in HC subjects. In patients <70 years, anastrozole treatment led to a significant increase in uNTx compared with age-related HC subjects (1.74 vs. 1.55, P < 0.005). Patients >70 years showed no such increase compared to HC (1.72 vs. 1.69, nonsignificant); however, NDBC women >70 years had uNTx levels significantly lower than HC women (1.59 vs. 1.69, P < 0.05). There was no difference in uNTx levels above and below the age of 70 years in NDBC women (1.56 vs. 1.59, nonsignificant). ABC women were more likely to have a positive LS BMD z score than age-matched controls. Anastrozole treatment increases bone turnover more in younger postmenopausal women with breast cancer than in older women compared to healthy controls. Higher LS BMD in ABC patients may help protect against fracture.

Keywords

Aromatase inhibitor Elderly Bone resorption Breast cancer Postmenopausal