Olaparib In Metastatic Breast Cancer

* This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific cancer. "Investigational" means that the study drug, Olaparib, is being studied for use in this setting and the research doctors are trying to learn more about it-the side effects it may cause and if the drug is effective in treating this type of cancer. * What is a DNA repair gene mutation? \-- In order to survive, all cells, even cancer cells, must be able to repair their genetic material (DNA) when it gets damaged. A mutation is an alteration or change in a gene- either inherited from a parent or acquired over time- that prevents the gene from working properly. Faulty genes (or genes that carry a mutation) have been linked to increased risk of hereditary breast and ovarian cancer. * What is Olaparib? * Olaparib is a drug that may stop cancer cells from growing. Olaparib is a PARP inhibitor which means that it blocks an enzyme (proteins that help chemical reactions in the body occur) in cells called PARP. PARP helps repair DNA when it becomes damaged. It has been shown that the tumors in individuals who have inherited or acquired a mutation in the BRCA1 or BRCA2 genes are often sensitive to killing by PARP inhibitors. * In normal cells and many other tumors, repair of damage to the DNA requires pathways of genes that work with BRCA1 and BRCA2. Therefore, when a drug that inhibits PARP from working is given to people with a BRCA mutation, or a defect in another gene that works with BRCA1 and BRCA2, both ways of repairing damaged DNA no longer work. The combined effect of knocking out both DNA repair mechanisms is so severe that the cancer cells could die. This might stop the growth of type of breast cancer, but this is not known. * The FDA (U.S. Food and Drug Administration) has approved Olaparib for use in advanced ovarian cancer with a BRCA1 or BRCA2 mutation. Olaparib is not approved for breast cancer.