 - Previously obtained tumor sample exhibits a hypermutator phenotype. For the purposes of this trial, a hypermutator phenotype is defined as tumors harboring 30 mutations non-synonymous somatic point or indel mutations detected by the MSK-IMPACT or comparable next generation sequencing performed in a CLIA environment. Contingent to approval by the MSK Principal Investigator, patients with less than 30 mutations may be eligible if they display a mutation in a mismatch repair gene or other mutations in genes known to be associated with hypermutator phenotypes or microsatellite instability, including but not limited to MLH1, MSH2, MSH6, PMS2, POLE, POLD as determined by validated methods, or if microsatellite instability is present, as identified by polymerase chain reaction PCR or other validated methods. 