Determination of Copper and Other Trace Elements in Serum Samples From Patients With Biliary Tract Cancers

Inclusion Criteria: * aged ≥18 years * cytologically or histologically verified biliary tract cancer * no prior systemic therapy and no radiation therapy for advanced, inoperable or metastatic disease * WHO performance status 0 - 2 (ECOG criteria) * imaging diagnosis (CT of thoracic and abdominal organs) performed within 4 weeks prior to the first administration of systemic therapy * disease measurable by RECIST or ECOG criteria * signed Consent to Participate in Clinical Research form Exclusion Criteria: * prior systemic treatment and radiation therapy for inoperable, metastatic disease * WHO performance status \> 2 (ECOG criteria) * contraindications to immunotherapy (known immunodeficiency or active immunosuppressive therapy or active autoimmune disease requiring treatment) * other malignancies, except cured basal cell or squamous cell carcinoma of the skin, in situ carcinoma of the cervix or other cured solid tumours without recurrence ≥ 3 years after treatment.