With survival prolongation, the number of breast cancer patients with bone marrow metastases (BMM) has increased. However, pathological diagnosis of BMM is rare and its features remain unclear in clinical practice. The prognosis of BMM is generally poor, so there is a struggle in the therapeutic strategy due to the serious complications. The objective of this study was to assess the clinico-pathological characteristics and prognosis of breast cancer with BMM at our institution.
BMM was defined as presence of juvenile neutrophils and erythroblasts in peripheral blood. Among the 187 breast cancer patients treated for bone metastases therapy between 2010 and 2014, 47 patients diagnosed with BMM were retrospectively analyzed.
Bone was the first site of metastasis in majority of patients (n = 42, 89.4%). Scirrhous carcinoma was the most frequent (n = 22, 69%). Forty-two patients (89.4%) were ER-positive, and six patients (14.3%) were HER2-positive. Grade 3 or more hematological findings were thrombocytopenia (n = 9, 19.1%), anemia (n = 13, 27.7%), and leukopenia (n = 6, 12.8%). In biochemical findings, ALP and LDH were increased in 15 patients (31.9%), and 20 patients (42.5%) respectively. Twenty-seven patients received systemic therapy, whose clinical benefit rate (CBR) was 29.8% (14/27). Alhough significant prognostic factors were not determined, higher ALP and LDH tended to be associated with poor prognosis. There was no association between the period from first recurrence to BMM diagnosis and the treatment outcome. The median survival time (MST) after BMM diagnosis was 3.5 months. Among those who received systemic therapy, MST was 13.5 months in CBR group, and 4.0 months in the progressive disease group. The no-treatment group had significantly poor prognosis with 0.8 months.
BMM is associated with poor prognosis: however, our findings suggest that it is possible to improve BMM prognosis by systemic therapy. Peripheral blood findings is a simple and significant diagnostic tool for BMM, which is observed before appearance of cytopenia that should not be missed in clinical practice.
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All authors have declared no conflicts of interest.