For more information regarding Bristol-Myers Squibb Clinical Trial participation, please visit www.BMSStudyConnect.com  Inclusion Criteria:  Adult participant (≥18 years of age) enrolling into the squamous cell (including adenosquamous) oesophageal cancer early access to medicines scheme (EAMS) and plans to initiate treatment with nivolumab Willing and able to comply with the study requirements and provide informed consent  Exclusion Criteria:  • Does not receive at least one dose of nivolumab as part of the EAMS  Other protocol-defined inclusion/exclusion criteria apply