Bone mineral density in breast cancer patients with positive estrogen receptor tumor status

AimThe aim was to investigate bone mineral density (BMD) in breast cancer patients with positive estrogen receptor (ER) tumor status.MethodsThe participants were 110 postmenopausal breast cancer patients with positive estrogen receptor (ER+) tumor status. Two hundred and sixty-one age-matched, healthy postmenopausal women, all of whom were selected from our pooled data, served as controls. Age, age at menopause, years since menopause (YSM), height, weight, and body mass index (BMI, wt/ht2) were recorded. Lumbar spine (L2–4) BMD and Z-score were assessed by dual-energy X-ray absorptiometry.ResultsBone mineral density in breast cancer patients was significantly higher than that in controls (0.89 ± 0.12 g/cm2 versus 0.84 ± 0.16 g/cm2, P < 0.01). The Z-score in breast cancer patients was also higher than that in controls (110 ± 13.6% versus 100 ± 9.8%, P < 0.001). Higher BMD and Z-score in breast cancer patients remained significant after adjusting for age, YSM, and BMI (P < 0.05).ConclusionsPostmenopausal breast cancer patients with positive ER tumor status have higher BMD. Positive ER tumor status may be associated with higher cumulative exposure to estrogen.