Diagnosis, management and clinical outcome of bone metastases in breast cancer patients: results from a prospective, multicenter study

Little information is available about the management and clinical outcome of bone metastases (BM) in breast cancer patients.We prospectively studied 459 breast cancer patients with first diagnosis of BM for at least 2 years to collect information about diagnosis, management and clinical outcome.Two hundred and forty-eight patients (54%) had only BM, 86 (18.7%) had concomitant nonskeletal BM and 125 (27.2%) had previous nonskeletal BM. At enrolment, skeletal-related events were present in 132 patients (28.8%). Cancer treatments consisted of hormones (227/459, 49.5%) or chemotherapy (192/459, 41.8%). Age (< or =70) and nonskeletal BM are inversely correlated with the use of chemotherapy or endocrine treatment (p < 0.0001). Bisphosphonates were used in 67.5% of the cases, alone (62.3%) or combined with other drugs. After a median follow-up of 28 months (range 2-43), 272 patients developed new metastases (59.2%), progression occurred mainly in nonskeletal sites (107/459, 23.3%), except for BM patients, who progressed prevalently at bone (69/248, 27.8%). New skeletal-related events were observed in 122 patients (26.6%). The 2-year probability for disease progression control and survival was 0.19 (95% CI 0.15-0.24) and 0.64 (95% CI 0.58-0.69), respectively. The 2-year probability for death according to the presence of nonskeletal metastases and the time of appearance (previous or concomitant to BM) was 0.74 (95% CI 0.67-0.79) for BM, 0.38 (95% CI 0.25-0.51) for previous nonskeletal BM and 0.56 (95% CI 0.46-0.66) for concomitant nonskeletal BM (p < 0.0001).Clinical outcome is significantly different according to the metastatic sites.