Breast Cancer Subtypes Predispose the Site of Distant Metastases

Objectives: The distant organs to which breast cancer preferentially metastasizes are of significant clinical importance. Methods: We explored the relationship between the clinicopathologic factors and the common sites of distant metastasis in 531 consecutive patients with advanced breast cancer. Results: Breast cancer subtype as a variable was significantly associated with all five common sites of relapse by multivariate analysis. The luminal tumors were remarkable for their significant bone-seeking phenotype and were less frequently observed in lung, brain, and pleural metastases and less likely to be associated with multiorgan relapse. The HER2 subtype demonstrated a significant liver-homing characteristic. African Americans were significantly less likely to have brain-only metastasis in patients with brain relapse. Conclusions: These findings further articulate that breast cancer subtypes differ not only in tumor characteristics but also in their metastatic behavior, thus raising the possibility that this knowledge could potentially be used in determining the appropriate strategy for follow-up of patients with newly diagnosed breast cancer. (C) American Society for Clinical Pathology