Bone metastases in breast cancer: Frequency, metastatic pattern and non-systemic locoregional therapy

BACKGROUND The study evaluates the frequency of and indications for bone-metastases (BM)-related surgery and/or radiotherapy in the palliative breast cancer (BC) situation and analyzes in which phase of the palliative disease course surgery and/or radiotherapy was applied. METHODS 340 patients who developed distant metastatic disease (DMD) and died (i.e. patients with completed disease courses) were analyzed. RESULTS From the entire study cohort, 237 patients (69.7%) were diagnosed with BM. Out of these, 116 patients (48.9%) received BM-related radiotherapy and/or surgery during the palliative situation. RADIOTHERAPY 108 patients (45.6%) received 161 series (range: 1-5) with 217 volumina (range: 1-8) on 300 osseous sites. At 75.3% of the radiated sites, the spine was the most frequent radiated location. Eighty-eight series (54.7%) were performed in the first third of the metastatic disease survival (MDS) period. The median survival after radiotherapy was 14 months (range: 0.2-121 months). SURGERY In 37 patients (15.6%), 50 procedures (range: 1-4) were necessary to stabilize BM. The femur predominated with 56.0% of the procedures. Twenty procedures (40.0%) were performed in the first third of survival follow-up. The median survival after surgery was 13.5 months (range: 0.5-49 months). BC patients with BM had a significantly improved MDS when radiotherapy and/or surgery for skeletal metastases was embedded in the palliative approach (27.5 months vs. 19.5 months, p<0.001). From the 118 patients who had a MDS of ≥24 months, the majority (54.2%) had BM-related radiotherapy and/or surgery during the palliative course. CONCLUSIONS Metastatic BC has become increasingly viewed as a chronic disease process. In a general palliative therapy approach, which allows for treatment according to the principles of a chronic disease, non-systemic therapy for BM, in particular radiotherapy, has a clearly established role in the therapy concept.