Developing Plasma DNA as a Surrogate for Tumor Biopsy to Identify Tumor Genetic Alterations in Patients With Advanced Breast Cancer

There are three major subtypes of breast cancer: 1. Hormone receptor positive (contain cells that express the estrogen receptor or progesterone receptor). 2. Tumors that express the epidermal growth factor receptor gene ( HER-2) 3. Triple negative (cancer cells that lack the hormone receptors and the epidermal growth factor receptor gene HER-2. While effective therapies exist for most cases of breast cancer at first occurrence, many patients eventually exhibit disease that does not respond to all standard breast therapies, particularly in the metastatic setting. There are therapies that are used to treat other types of cancers with genetic mutations that are in the process of being evaluated for use in breast cancer. The current techniques used for detecting mutations in the genes of breast cancer patients, which can be treated with drugs specific for the genetic mutations, are invasive and identifying effective diagnostic non-invasive procedures are the next challenge for physicians. This study will compare the ability to detect genetic mutations samples from non-invasive procedures such as a blood draw, to more invasive procedures such as tissue taken from a biopsy sample. There is also a concern with current techniques used to detect genetic mutations that cells from a single tissue sample may not be representative of the types of cells present in all the tumors in the body and therapies selected using a single tissue sample may not be effective for all of the cancer in the body. This study will use blood drawn from participants prior to any drug therapy and compare the genes from this blood to tissue samples from multiple sites of disease. The study will also compare the genetic profile of the metastatic tumors to the genetic profile of the original breast cancer to determine if there are any changes in the genetics of the tumor cells. The participants that have newly diagnosed metastatic disease will provide tissue from their primary site of disease via a