Survival in Breast Cancer Patients with Bone Metastasis: A Multicenter Real-World Study on the Prognostic Impact of Intensive Postoperative Bone Scan after Initial Diagnosis of Breast Cancer (CSBrS-023)

SIMPLE SUMMARY: The bone scan (BS) is widely used in follow-up to detect bone metastasis (BM) in breast cancer (BC) patients presenting bone-related symptoms after surgery. However, it remains controversial whether asymptomatic BS (intensive postoperative BS) screening could be translated into a survival benefit. Therefore, we conducted this multicenter real-world study to understand the prognostic impact of intensive postoperative BS screening among 1059 Chinese patients with BM during the years 2005–2013. This study showed that intensive postoperative BS screening was an independent prognostic factor and prolonged the survival in patients with BC with BM. The prognostic value of intensive BS screening was consistently favorable for survival in patients at clinical high-risk. These findings suggested that intensive BS screening was important for improving survival, and should be recommended for postoperative surveillance, especially for patients with a high risk of recurrence and metastasis. ABSTRACT: The prognostic value of intensive postoperative bone scan (BS) screening, which is performed in asymptomatic patients with breast cancer (BC) after surgery, remained unclear. Patients diagnosed with BC with bone metastasis (BM) from five medical centers in China during the years 2005–2013 were retrospectively collected. Propensity score matching (PSM) was performed to balance the baseline characteristics. The survival outcomes were overall survival (OS) and overall survival after BM (OSABM). Among 1059 eligible patients, 304 underwent intensive postoperative BS while 755 did not. During a median follow-up of 6.67 years (95%CI 6.45, 7.21), intensive postoperative BS prolonged the median OS by 1.63 years (Log-Rank p = 0.006) and OSABM by 0.66 years (Log-Rank p = 0.002). Intensive postoperative BS was an independent prognostic factor for both OS (adjusted HR 0.77, 95%CI 0.64, 0.93, adjusted p = 0.006) and OSABM (adjusted HR 0.71, 95%CI 0.60, 0.86, adjusted p < 0.001). The prognostic value of intensive postoperative BS was consistently favorable for OS among clinical high-risk patients, including those with ages younger than 50, stage II, histology grade G3 and ER-Her2- subtype. This multicenter real-world study showed that intensive postoperative BS screening improved survival for BC patients with BM and should probably be recommended for postoperative surveillance, especially for patients at clinical high-risk.