Immunotherapy shows satisfactory effectiveness and safety in patients with esophageal cancer. Immunotherapy-based regimens have a better survival benefit compared to previous chemotherapy and radiotherapy. Patient-reported outcomes (PRO) provide a reliable assessment of patients' functional status during treatment. However, the spectrum of symptoms in esophageal cancer patients receiving immunotherapy is uncertain, and there are no studies applying the symptom bank based on PRO to the immunotherapy model for esophageal cancer. In this prospective study, the investigators aimed to preliminarily screen for symptoms associated with immunotherapy for esophageal cancer through a systematic literature review and expert evaluation, and build a symptom item bank for esophageal cancer patients receiving immunotherapy. Adverse symptoms in esophageal cancer patients treated with immunotherapy were collected prospectively. The distribution and severity of the symptoms, as well as the trajectory of symptom change were further analyzed to demonstrate the validity and reliability of the symptom item bank. It would refine the spectrum of symptoms for esophageal cancer patients receiving immunotherapy and provide a foundation for assessing the specific symptom burden in patients with esophageal cancer receiving immunotherapy regimens.

Inclusion Criteria:

• Pathologically confirmed resectable, locally advanced, advanced metastatic esophageal cancer
• Having received or undergoing an immunotherapy-based treatment regimen
• Age 18-75 years
• ECOG PS of 0-2
• Adequate organ function
• Life expectancy > 6 months
• Participants are fully informed about the whole study and are willing to sign the informed consent

Exclusion Criteria:

• Absence of immunotherapy regimen, or recieving radiotherapy.
• Presence of primary tumours elsewhere, such as gastric cancer, lung cancer or cervical cancer
• Severe organ function deterioration and intolerance to immunotherapy
• Pregnant or breast-feeding women
• Previous autoimmune disease
• Any other conditions that may affect patients' safety and compliance
• Psychological, family, social and other factors leading to inability to inform consent

The target population of the study is patients with esophageal cancer who have received or are receiving immunotherapy-based regimens in various stages, including resectable, locally advanced, and advanced stages.