Comparing Dosing Intervals of Nivolumab or Pembrolizumab in Locally Advanced or Metastatic Cancers

Inclusion Criteria: * Patients with locally advandced or metastatic cancer whose physician has determined they are candidates for treatment with nivolumab or pembrolizumab * 18 years old or older * Measurable disease per RECIST criteria Exclusion Criteria: * Patients who have previously received immune checkpoint inhibitors or investigational monoclonal antibody therapy. * Patients whose treatment plan is to receive ipilimumab or other anti-CTLA4 monoclonal antibody in combination with either nivolumab or pembrolizumab. * Ipilimumab and nivolumab combination are not eligible for this trial. * (Note: Patients whose planned treatment is the combination of anti-PD-1 and tyrosine kinase inhibitor such as pembrolizumab-axitinib or the combination of traditional cytotoxic chemotherapy and anti-PD-1 are eligible)