Background: Tumor microenvironment is composed of a largely altered extracellular matrix with different cell types. The complex interplay between macrophages and tumor cells through several soluble factors and signaling is an important factor in breast cancer progression. Methods: We have extended our earlier studies on monocyte and macrophage conditioned medium (MϕCM) and have carried out proteomic analysis to identify its constituents as well as validation. The 8-gene signature identified through macrophage-breast cancer cell interactions was queried in cBioportal for bioinformatic analyses. Results: Proteomic analysis (MALDI-TOF and LC-MS/MS) revealed integrin and matrix metalloproteinases in MϕCM which activated TGF-β1, IL-6, TGF- βRII and EGFR as well as its downstream STAT and SMAD signaling in breast cancer cells. Neutralization of pro-inflammatory cytokines (TNF-α. Il-1β, IL-6) abrogated the MϕCM induced migration but invasion to lesser extent. The 8- gene signature identified by macrophage-tumor interactions (TNF-α, IL-1β, IL-6, MMP1, MMP9, TGF-β1, TGF-βRII, EGFR) significantly co-occurred with TP53 mutation, WTAPP1 deletion and SLC12A5 amplification along with differential expression of PSAT1 and ESR1 at the mRNA level and TPD52and PRKCD at the protein level in TCGA (cBioportal). Together these genes form a novel 15 gene signature which is altered in 63.6% of TCGA (1105 samples) data and was associated with high risk and poor survival (p<0.05) in many breast cancer datasets (SurvExpress). Conclusions: These results highlight the importance of macrophage signaling in breast cancer and the prognostic role of the15-gene signature. General significance: Our study may facilitate novel prognostic markers based on tumor-macrophage interaction.Keywords: Gene signature; MMP; Macrophages; Proteomics; TCGA.