Patient description: The patient is a 33-year-old woman complained of fatigue, weight gain and abnormal spotting between menses. No hirsutism or nipple discharge was detected. Her BMI was 34. Her lab results were remarkable for high TSH level (13 mU/L) and low free T4 level (0.2 ng/dl). Her anti-TPO levels were extremely high (120 IU/ml). She was diagnosed with Hashimoto's thyroiditis. Her aunt, brother and mother have the same disease. After starting 250 mcg Levothyroxine per day, her symptoms improved significantly and her periods are normal. She is still overweight with BMI of 31. Her most recent thyroid profile revealed all results except for anti-TPO within the normal range: TSH: 2.35 mU/L Free T4: 2.7 ng/dl Anti-TPO: 75 IU/ml

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Estrogen Receptor Negative HER2/Neu Negative Invasive Breast Carcinoma Progesterone Receptor Negative Recurrent Breast Carcinoma Stage IV Breast Cancer Triple-Negative Breast Carcinoma Patients must have histologically or cytologically confirmed metastatic invasive breast cancer that is negative for the estrogen receptor (ER), progesterone receptor (PR) and HER2 by institutional guidelines Patients must have measurable disease (Response Evaluation in Solid Tumors version 1.1 [RECIST 1.1]) Patients must have had exposure to at least 1 and no more than 3 prior chemotherapy regimens for the treatment of metastatic breast cancer Patients must consent to both a pretreatment and a post-treatment mandatory research biopsy prior to enrolling on trial, and therefore, must have tissue (excluding bone or brain) that is amenable to biopsy Eastern Cooperative Oncology Group (ECOG) performance status 0-1 Life expectancy of greater than 3 months Able to swallow and retain orally administered medication and does not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels All prior treatment-related toxicities must be Common Terminology for Adverse Events version 4 (CTCAE v4) grade =< 1 (except alopecia) at the time of enrollment Absolute neutrophil count >= 1,500/mcL Platelets >= 75,000/mcL  History of another malignancy Exception: patients who have been disease-free for 3 years, or patients with a history of completely resected non-melanoma skin cancer and/or patients with indolent secondary malignancies, are eligible History of interstitial lung disease or pneumonitis History of type I diabetes mellitus; if a patient has type II diabetes, they must have a hemoglobin (hemoglobin A1C) =< 8%; patients with a screening fasting glucose > 120 mg/dL will be excluded Uncontrolled hypothyroidism; patients must have a normal thyroid-stimulating hormone (TSH) per institutional standards at baseline Patients who are receiving any other investigational agents Individuals with symptomatic or progressive brain metastases are ineligible; subjects with treated brain metastases are eligible if they have no radiographic or other signs of progression in the brain for >= 3 weeks after completion of local therapy; any corticosteroid use for brain metastases must have been discontinued without the subsequent appearance of symptoms for >= 3 weeks prior to study enrollment History of allergic reactions attributed to compounds of similar chemical or biologic composition to trametinib monotherapy or trametinib in combination with GSK2141795 Current use of a prohibited medication; the following medications or non-drug therapies are prohibited Other anti-cancer therapy while on study treatment (megestrol if used as an appetite stimulant is allowed)