Patient description: The patient is a 45-year-old postmenopausal woman with cytologically confirmed breast cancer. A core biopsy revealed a 3 cm invasive ductal breast carcinoma in the left upper outer quadrant. The tumor is HER2-positive and ER/PR negative. Axillary sampling revealed 5 positive lymph nodes. CXR was remarkable for metastatic lesions. The patient is using multivitamins and iron supplements. She does not smoke or consume alcohol. She is not sexually active and has no children. She is a candidate for tumor resection and agrees to do so prior to chemotherapy.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Endometrial Cancer Endometrial Carcinoma Neoplasms, Endometrial Diagnosis of FIGO grade 3 endometrioid cancer, serous, clear cell, or mixed high grade endometrial cancer with confirmation on research-related endometrial biopsy Radiographically confirmed endometrial adenocarcinoma of stages III-IV requiring adjuvant therapy. If stage III disease is suspected, there should be multiple pelvic and/or lymph nodes involved Measurable disease defined as lesions that can be accurately measured in at least one dimension (longest diameter to be recorded) as >10 mm with CT scan, as >20 mm by chest x-ray, or >10 mm with calipers by clinical exam by 1.1 Treatment plan must primary site biopsy followed by resection of the primary tumor site and any metastatic sites at time of surgery At least 18 years of age GOG performance status ≤ 2 Normal bone marrow and organ function as defined below Absolute neutrophil count ≥ 1,500/mcl Platelets ≥ 100,000/mcl Hemoglobin ≥ 9 g/dL  FIGO grade 1 or 2 endometrioid cancer Radiographic imaging demonstrating uterine cancer that is probably stage I or II Prior treatment for endometrial cancer Prior treatment with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent Prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to first dose of MK-3475 or has not recovered (i.e., to ≤ grade 1 or baseline) from adverse events due to agents administered more than 4 weeks earlier Prior chemotherapy, targeted small molecule therapy, or radiation therapy within 2 weeks prior to the first dose of MK-3475 or has not recovered (i.e., to ≤ grade 1 or baseline) from adverse events due to a previously administered agent. Note, subjects with ≤ grade 2 neuropathy are an exception to this criterion and may qualify for the study. Note, if a subject received major surgery, she must have recovered adequately from the toxicity and/or complications from the intervention prior to starting therapy Received a live vaccine within 30 days prior to the first dose of MK-3475. Examples of live vaccines but are not limited to, the following: measles, mumps, rubella, varicella/zoster (chicken pox), yellow fever, rabies, Bacillus Calmette-Guérin (BCG), and typhoid vaccine. Seasonal influenza vaccines for injection are generally killed virus vaccines and are allowed; however, intranasal influenza vaccines (e.g. FluMist) are live attenuated vaccines and are not allowed A history of other malignancy ≤ 5 years previous with the exception of basal cell or squamous cell carcinoma of the skin which were treated with local resection only Known active central nervous system metastases and/or carcinomatous meningitis. Subjects with previously treated brain metastases may participate provided they are stable (without evidence of progression by imaging for at least 4 weeks prior to the first dose of MK-3475 and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroids for at least 7 days prior to trial treatment. This exception does not carcinomatous meningitis which is excluded regardless of clinical stability Diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy in dosing exceeding 10 mg daily of prednisone or equivalent) or any other form of immunosuppressive therapy within 7 days prior to the first dose of MK-3475