Multicenter Italian bone metastasis database: First prospective data on breast cancer patients.

Abstract

e13072 Background: Bone Metastases (BM) are still the main cause of morbidity and morbility in cancer patients because of their complications defined as skeletal-related events (SREs).SREs reduce pts quality of life and are associated with an increasing in social and health costs. At present, data concerning BM are mainly obtained retrospectively from monocentric experiences. Methods: We performed a multicentre prospective observational study of patients with BM from breast cancer (BC) with at least 6 month (m)'s follow-up who were registered in a prospective BM database (BMDB). Detailed information on patients at first diagnosis of BM was recorded in a custom-built software system, updated every 6 m by participating centres and reviewed by the coordinator centre.All pts have signed an informed consent. Results: Since October 2014,618 pts with BM from solid tumors were enrolled of whom 220 have BC as primitive site with a 6 m follow-up. Median age was 62 y (range 26-86). Median Follow up was 34 m (6-149). At enrolment 109 (50%) had only BM and 109 (50%) pts had concomitant visceral and BM. Median time to first BM was 47 m (range 0-312) in Bone only disease and 78.6 m in pts with visceral bone metastases. Disease Free interval (DFI) was different according to BC molecular subtypes and stage. The univariate hazard ratio (HR) for visceral or bone metastasis was higher in luminal B tumors (1.56, 95% confidence interval [CI]:1.1-2.3) (p = 0.002), basal-like (2.50, 95% CI:1.1-6.0) (p = 0.043), and HER2-enriched tumors (1.37, 95% CI:0.78-2.4) (p = 0.273). DFI for pts with stage I disease at diagnosis of primary BC was longer than that for stage III pts (median 67.2 m, 95%CI:53.1-96.1, vs. 58.1 m, 95%CI:41.9-73.4), with a HR of 1.84 (95% CI:1.1-3.0) (p = 0.015) for the stage III group, and 0.98 (95% C.I.:0.6-1.5) (p = 0.930) for the stage II group. During BM disease, 98 pts had at least 1 SREs . Zoledronate was used in 69.1% and Denosumab in 28.3% of cases. First line treatment was hormone-based (n = 105, 50.7%) chemo-based therapy (n = 80, 38.7%) and chemo+ormono based (n = 20, 9.7%). During follow up progression disease occurred in 167 pts. Median progression-free (mPFS) and overall survival calculated from metastatic disease diagnosis (mOS) were 15.1 m (95%CI 12.6-18.4) and 66.8 m (95%CI 52.1-79.2),respectively. Conclusions: This study presents prospective data about a cohort of BC pts enrolled at the first BM occurrence and followed over the time, extrapolated by the multicentric observational BMDB in order to better understed the clinical history of breast cancer and bone metastases.