Lamellipodin (Lpd) is a protein that is involved in the migratory ability of cancer cells. These inventors demonstrate that Lpd is required for metastatic spread using in vitro and in vivo metastasis models. In human tumor samples, moderate levels of Lpd protein at the plasma membrane of tumor cells is highly correlated with a greater risk of metastatic dissemination, disease progression, and breast cancer related death. This technology could easily be included alongside the panel of immunohistochemical tests already commonly performed on breast cancer tumors to provide prognostic data on metastatic risk. Finally, the inventors also suggest the potential of targeting Lpd therapeutically, and they demonstrated that knockdown of Lpd leads to decreased metastasis in an in vivo mouse transplant model of breast cancer.