Abstract P2-08-26: Tumor-associated macrophages and platelet-derived growth factor C as a prognostic marker for breast cancer patients

Abstract

Abstract Introduction: Tumor related inflammation plays an important role in breast cancer progression, tumor-associated macrophages (TAMs) being a crucial part of this microenvironment. Platelet-derived growth factor-C (PDGF-C) is abundant in the breast cancer microenvironment having an anti-apoptotic effect on macrophages. Previous reports suggest that tumor cell derived PDGF-C promotes TAM survival, enhancing tumor progression. In this study we analyzed the prognostic value of PDGF-C density associated with TAM infiltration in human breast cancer. Materials and Methods: TAM and PDGF-C density was evaluated by immunohistochemistry of CD163+, CD68+ and PDGF-C myeloid cells in tumor stroma. Tissue microarrays from 140 invasive breast cancer cases were used. Survival analysis to evaluate the impact of TAM and PDGF-C density on disease free survival (DFS) was done using Kaplan-Meier and Cox regression analysis. Results: Infiltration of CD163+ and CD68+ macrophages into tumor stroma had a tendency, but not significant, for reduced DFS (p=0.204, p=0.314 respectively). Whereas PDGF-C strong density was significantly associated with worse DFS (p=0.024). This inverse correlation with DFS was demonstrated stronger when PDGF-C density was combined with CD163+ and CD68+ macrophage infiltration (p=0.008, p=0.018, respectively). But, CD163+ or CD68+ infiltration with strong PDGF-C density did not demonstrate as an independent prognostic factor when adjusting for tumor size, lymph node metastasis, hormone receptor and histologic grade. This result is probably due to small number of patients having both TAM infiltration and strong PDGF-C density. Conclusion: Our results show that PDGF-C infiltration adversely affects DFS and also enhances the inverse correlation between tumor-associated macrophages and DFS. To support these results, a study with larger numbers is on progress. Citation Format: Yoo T-K, Lee K-M, Jung H, Na YR, Seok SH, Han W. Tumor-associated macrophages and platelet-derived growth factor C as a prognostic marker for breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-26.