Platinum for Triple-Negative Metastatic Breast Cancer and Evaluation of p63/p73 as a Biomarker of Response

This study is a Phase 2 study designed to evaluate cisplatin/carboplatin as first or second line therapy in metastatic triple negative (ER negative, PR negative, Her2 Negative) breast cancer and to evaluate the expression of p63/p73 as a biomarker to predict response. * Participants will be given a cisplatin or carboplatin infusion intravenously on the first day of each treatment cycle. Each treatment cycle will last 3 weeks. Treating physician will select agent up to 41 patients in each cohort. Final primary endpoint analysis will use combined cis/carbo results. * During all treatment cycles participants will have a physical exam (including weight and vital signs) and they will be asked general questions about their health and any medications they may be taking, as well as specific questions about any side effects they may be experiencing while receiving study treatment. * During every treatment cycle participants will have standard blood tests to check blood counts, liver and kidney function, and a blood marker for you particular type of cancer. * CT scans will be taken of the participants tumor every 2 to 3 cycles to assess the response of the tumor to cisplatin. * Participants will be in this study for as long as they tolerate the study treatment and their disease does not get any worse. * Participants will be required to have a sample of their original tumor sent to Massachusetts General Hospital for correlative studies, or a sample from a metastatic diagnostic biopsy. * Patients with accessible tumor will be asked to provide an optional metastatic tumor biopsy for correlative studies.