Role of breast surgery in T1-3 breast cancer patients with synchronous bone metastases

The impact of breast surgery on survival of metastatic breast cancer (MBC) patients is controversial. We addressed the question in a mono-institutional series of MBC patients with synchronous bone metastases. We identified 187 consecutive women diagnosed between 2000 and 2008 with locally operable (T1–T3) MBC, synchronous bone metastases, with no other distant sites being involved. Progression-free survival (PFS) and overall survival (OS) were compared between operated and non-operated patients. Median age was 51 years; 92 % of the women had a hormone-positive tumor. At the time of diagnosis, 131 patients out of 187 (70 %) underwent surgery. Operated and non-operated patients differed in terms of number of bone metastatic sites: a single metastasis was detected in 35 (28 %) operated, and 6 (11 %) non-operated cases (P = 0.01). No other significant differences were observed. The multi-adjusted hazard ratio was 0.63 (95 % CI 0.43–0.92) for PFS and 0.64 (95 % CI 0.41–0.99) for OS in favor of surgery. The 5-year cumulative incidence of ipsilateral breast skin progressions among non-operated patients was 18 %. In this large and homogeneous series of MBC patients with synchronous bone metastases, the role of breast surgery had a favorable impact on both disease progression and mortality.