Correlations between Serum Monocyte Chemotactic Protein-1 Levels, Clinical Prognostic Factors, and HER-2/neu Vaccine-Related Immunity in Breast Cancer Patients

Purpose: We studied serum monocyte chemotactic protein-1 (MCP-1) levels in breast cancer patients in relationship to their clinicopathologic variables and immune response to a / neu E75 vaccine. Experimental Design: We measured MCP-1 levels in 32 / neu + breast cancer patients before and after vaccination with a / neu E75 peptide + granulocyte macrophage colony-stimulating factor vaccine. Clinical prognostic variables were collected. Vaccine-specific immunologic responses were monitored. Results: Serum MCP-1 levels >250 pg/mL (MCP-high) correlated with favorable prognostic variables. MCP-high patients compared with MCP-low (50% increase in MCP-1 levels (response-high) had worse clinical prognostic variables compared with patients with 30% postvaccination MCP-1 increase also showed significant increases in E75-specific CD8 + T-cells (0.05% versus 0.38%; P = 0.03) in response to vaccination. Conclusions: High serum MCP-1 levels in breast cancer patients correlate with favorable prognostic variables and increased preexisting / neu immunity. E75 vaccination induces the largest MCP-1 response in patients with unfavorable clinicopathologic variables. Therefore, low serum MCP-1 levels may identify patients with worse prognosis and those most likely to benefit from this vaccination.