Triple negative breast cancers (TNBC) are aggressive tumors, with high rates of metastatic spread and targeted therapies are critically needed. We aimed to assess the prognostic and predictive value of a 3q 19-gene signature identified previously from lung cancer in a collection of 4,801 breast tumor gene expression data. The 3q gene signature had a strong association with features of aggressiveness such as high grade, hormone receptor negativity, presence of a basal-like or TNBC phenotype and reduced distant metastasis free survival. The 3q gene signature was strongly associated with lung metastasis only in TNBC (P < 0.0001, Hazard ratio (HR) 1.44, 95% confidence interval (CI), 1.31-1.60), significantly associated with brain but not bone metastasis regardless of TNBC status. The association of one 3q driver gene FXR1 with distant metastasis in TNBC (P = 0.01) was further validated by immunohistochemistry. In addition, the 3q gene signature was associated with better response to neoadjuvant chemotherapy in TNBC (P < 0.0001) but not in non-TNBC patients. Our study suggests that the 3q gene signature is a novel prognostic marker for lung and/or brain metastasis and a predictive marker for the response to neoadjuvant chemotherapy in TNBC, implying a potential role for 3q genes in the mechanism of organ-specific metastasis.