Biobanking Upper Gastrointestinal Tumors to Evaluate Response (BURGER With BACON)
The goal of this observational study is to examine genetic changes that may contribute to immunotherapy resistance in gastroesophageal cancer. This information can potentially lead to the identification of new immunotherapeutic targets as well as improve the ability to identify those patients more likely to respond to immunotherapy.

This study does not include any treatment or investigational drugs.

Participants will be asked:

to enroll before beginning standard care of treatment for their cancer
for blood, archived tumor tissue, and fresh tumor tissue Researchers will compare participants who are not getting immunotherapy to identify potential differences in expression levels of a gene.
- EligibilityCriteria: Cohort A (GE Cohort) For this study, a maximum of 40 evaluable patients with gastroesophageal adenocarcinoma and 20 patients with squamous cell carcinoma who will receive anti-PD-1 treatment as standard of care treatment will be enrolled (combination therapy regimen with other agents are allowed). Evaluable patients are those that have received at least one dose of anti-PD-1 treatment. 10 patients who are ineligible for immunotherapy will also be enrolled to meet the exploratory objective.  Inclusion Criteria:  Age > 18 years Ability to understand and the willingness to sign a written informed consent document Diagnosis of gastric, esophageal, or gastroesophageal junction adenocarcinoma or squamous cell carcinoma. Available archival tumor tissue or willingness to undergo research biopsy.  Exclusion Criteria:  Patients unable to comply with the requirements of the study protocol Patients known to be pregnant or nursing Serious pre-existing medical condition, that in the opinion of the investigator, makes the patient unsuitable for the study  Cohort B (Melanoma Cohort)  1. All subjects that consented and enrolled to Pro00059349 will be rolled into this protocol for specimen analysis. See Pro00059349 for eligibility criteria for those subjects.  Cohort C (Retrospective Cohort) Eligibility Criteria  GE subjects must have been treated with an immune checkpoint inhibitor for gastroesophageal adenocarcinoma or squamous cell carcinoma, or have been ineligible for immunotherapy due to low PD-L1 and received chemotherapy.  Melanoma subjects in cohort C must have stage II, III, or IV disease validated by histology or cytology  Primary cutaneous melanomas or melanomas of unknown primary site are eligible Melanoma subjects must have been treated with immunotherapy (combination with other agents not allowed) Patients with intra-cranial disease or disease involving the central nervous system are eligible. - HealthyVolunteers: No - Gender: All - MinimumAge: 18 Years - StdAgeList: Adult, Older Adult - StudyPopulation: This study will be open to men and women of age 18 or above who meet the above patient selection criteria (section 4.0). Once a Cohort A patient is identified, a provider known to the patient will introduce the study, and if the patient is interested, a member of the study team will consent and enroll the patient. Cohort B subjects were already consented for this research under Pro00059349. Cohort C patients will be identified using DEDUCE as described in section 3.0.  Patients will not be compensated for study participation. - SamplingMethod: Non-Probability Sample