Importance of Metastasis Site in Survival of Patients with Breast Cancer

Purpose: The purpose of this study is to analyze the survival rate of patients with metastatic breast cancer according to the location of metastases and to identify factors related to survival in these patients. Methods: The data of 184 patients who were treated for metastatic breast cancer at the Cumhuriyet University Oncology Center between 2006 and 2013 were retrospectively reviewed. Results: One hundred eighty-one patients (98%) in the study were female and three were male (2%). The median age at diagnosis was 51 years (range: 18-83 years). Following development of the first metastasis, median survival of the patients was 27 months (1-177 months), two-year survival was 55%, and five-year survival was 27%. The longest survival duration was in the patients with bone metastases, and the shortest survival was noted in patients with brain metastases. Age, menopausal status, diabetes mellitus, performance status, number of metastases (single organ vs. multiple organs), localization of the metastases (bone, liver, and brain metastasis), ER receptor status, grade, lymphovascular invasion, Ca 15.3 levels, and hemoglobin levels were the prognostic factors included in the univariate analyses. Based on the multivariate analyses, the independent prognostic factors affecting survival were diabetes mellitus, lymphovascular invasion positivity, high grade, hemoglobin levels < 12 g/dL, bone metastasis, and multiple organ metastases. Conclusion: The duration of survival in patients with metastatic breast cancer greatly varies based on the site of metastasis. The study results showed that among all the prognostic factors that play significant roles on the survival of patients with metastatic breast cancer, post-menopause, presence of diabetes mellitus, lymphovascular invasion positivity, high disease grade, and multiple organ metastases represent the poor independent prognostic factors; whereas presence of bone metastasis is a good independent prognostic factor.