Patients with cancer and concurrent autoimmune diseases (AID) have been universally excluded from clinical trials evaluating immunotherapy. Data on the safety and efficacy of checkpoint inhibitors in patients with underlying AID is limited. The investigators performed a retrospective multicenter review of medical records of patients with diverse tumor types and underlying AID who received checkpoint inhibitors at Departments of Oncology, affiliated with the Hellenic Cooperative Oncology Group (HeCOG). The primary endpoint was progression-free survival (PFS).

Inclusion Criteria:

• 18 years or older
• Patients with cancer
• Patients with autoimmune disease
• Treated at HeCOG-affiliated Departments of Oncology
• Early-stage or metastatic

Exclusion Criteria:

• diagnosis of the autoimmune disease after initiation of immunotherapy

Patients with diverse tumor types (early-stage or metastatic) who had received checkpoint inhibitors at HeCOG-affiliated Departments of Oncology Eligible patients had a history of AID, and had received treatment with checkpoint inhibitors as any of line of treatment