Most women with breast cancer about to initiate aromatase inhibitors already have bone loss

Abstract Women with breast cancer who receive aromatase inhibitors (AI) are at risk of bone mass loss and bone fracture. Many of these women have been previously treated with chemotherapy and/or tamoxifen, also with known deleterious bone effects. We studied the bone mineral status of a group of postmenopausal women with non-advanced breast cancer about to initiate AI treatment. Between 2007 and 2010, 127 women aged 63 ± 9 years were prospectively included. Clinical, epidemiological, analytical, radiological, and densitometric data were collected. Prior to initiating AI treatment, the patients exhibited a high prevalence of bone mass loss (62.2%): 16.5% had osteoporosis and 45.7% osteopenia by OMS criteria. Besides, 7.4% of their dorso-lumbar spine x-rays revealed one or more vertebral fractures, all of which were found in patients with densitometry-defined osteoporosis or osteopenia. Surprisingly, 25-OH-vitamin D levels were normal (≥30 ng/ml) in 87.4% of the women. Obesity was prevalent (BMI 30 ± 5). Their most common tumour was infiltrating ductal carcinoma (76.4%). The women who had received adjuvant chemotherapy (50%) were younger (59.1 ± 8.3 vs. 66.2 ± 8.2, p  This study shows that more than 60% of women about to initiate aromatase inhibitors for non-advanced breast cancer have low bone density and so high risk of fracture or re-fracture. These facts underscore the importance of screening their bone mass status and propose them preventive treatment.