- Histological confirmation of node positive (any T stage N1-3) proximal esophageal, distal esophagus or gastroesophageal (GE) junction adenocarcinoma (Siewert I, II, or III) after completing preoperative chemoradiation and surgery; supporting pathology report sufficient for registration; available tumor tissue from endoscopic biopsies prior to preoperative chemotherapy (chemo)/radiation therapy (RT), and tumor from surgical specimens will be submitted to Academic and Community Cancer Research United (ACCRU), but not be required prior registration; Note: if tissue is depleted, patient will still be eligible after discussion with the physician