DISEASE CHARACTERISTICS: Group I: Local or locoregional primary esophageal or esophago-gastric cancer Planned esophagectomy with or without adjuvant or neoadjuvant chemotherapy and/or radiotherapy OR Planned radical radiotherapy with or without chemotherapy Prior endoscopic procedure to relieve dysphagia allowed No distant liver or bone metastasis if undergoing esophagectomy Group II: Metastatic esophageal cancer or local anastomotic recurrence of esophageal cancer or deemed unsuitable for esophagectomy Prior palliation by endoscopic or open intubation, laser treatment, tumor necrosis with alcohol injection or diathermy, or intraluminal radiotherapy allowed Prior palliative radiotherapy or chemotherapy allowed No cerebral metastases