Clinical Stage IV Esophageal Adenocarcinoma AJCC v8Clinical Stage IV Esophageal Squamous Cell Carcinoma AJCC v8Clinical Stage IV Gastric Cancer AJCC v8Clinical Stage IVA Esophageal Adenocarcinoma AJCC v8Clinical Stage IVA Esophageal Squamous Cell Carcinoma AJCC v8Clinical Stage IVA Gastric Cancer AJCC v8Clinical Stage IVB Esophageal Adenocarcinoma AJCC v8Clinical Stage IVB Esophageal Squamous Cell Carcinoma AJCC v8Clinical Stage IVB Gastric Cancer AJCC v8Metastatic Colon CarcinomaMetastatic Esophageal CarcinomaMetastatic Gastric CarcinomaMetastatic Liver CarcinomaMetastatic Malignant Digestive System NeoplasmMetastatic Malignant Small Intestinal NeoplasmMetastatic Malignant Thoracic NeoplasmMetastatic Pancreatic CarcinomaMetastatic Rectal CarcinomaPathologic Stage IV Esophageal Adenocarcinoma AJCC v8Pathologic Stage IV Esophageal Squamous Cell Carcinoma AJCC v8Pathologic Stage IV Gastric Cancer AJCC v8Pathologic Stage IVA Esophageal Adenocarcinoma AJCC v8Pathologic Stage IVA Esophageal Squamous Cell Carcinoma AJCC v8Pathologic Stage IVB Esophageal Adenocarcinoma AJCC v8Pathologic Stage IVB Esophageal Squamous Cell Carcinoma AJCC v8Postneoadjuvant Therapy Stage IV Esophageal Adenocarcinoma AJCC v8Postneoadjuvant Therapy Stage IV Esophageal Squamous Cell Carcinoma AJCC v8Postneoadjuvant Therapy Stage IV Gastric Cancer AJCC v8Postneoadjuvant Therapy Stage IVA Esophageal Adenocarcinoma AJCC v8Postneoadjuvant Therapy Stage IVA Esophageal Squamous Cell Carcinoma AJCC v8Postneoadjuvant Therapy Stage IVB Esophageal Adenocarcinoma AJCC v8Postneoadjuvant Therapy Stage IVB Esophageal Squamous Cell Carcinoma AJCC v8Stage IV Colon Cancer AJCC v8Stage IV Hepatocellular Carcinoma AJCC v8Stage IV Pancreatic Cancer AJCC v8Stage IV Rectal Cancer AJCC v8Stage IV Small Intestinal, Esophageal, Colorectal, Mesenteric, and Peritoneal Gastrointestinal Stromal Tumor AJCC v8Stage IVA Colon Cancer AJCC v8Stage IVA Hepatocellular Carcinoma AJCC v8Stage IVA Rectal Cancer AJCC v8Stage IVB Colon Cancer AJCC v8Stage IVB Hepatocellular Carcinoma AJCC v8Stage IVB Rectal Cancer AJCC v8Stage IVC Colon Cancer AJCC v8Stage IVC Rectal Cancer AJCC v8