Enabling Genomic Testing in Cancer of Unknown Primary

Inclusion Criteria: 1. Aged 16 years or over 2. Written informed consent according to ICH/GCP and national regulations 3. ECOG Performance status 0-2 4. Confirmed diagnosis of CUP as per the ESMO guidelines. Patients must have; 1. The local pathology reports confirming compatibility with CUP diagnosis and the associated slides used for the diagnosis 2. Discussion at a local CUP MDT confirming diagnosis 5. Availability of archival tumour histological report 6. Willingness to provide blood samples on up to two occasions during the study Exclusion Criteria: 1. Patient with an immunohistochemistry profile that provides a definitive clinical indication of a primary cancer with a specific treatment 2. Known HIV, Hepatitis B, C positive, due to the difficulties in handling high-risk specimens 3. Patients who are unable to provide fully informed written consent 4. Presence of any medical, psychological, familial or sociological condition that, in the investigator's opinion, will hamper compliance with the study protocol and follow-up schedule 5. Bleeding diathesis (patients' on anticoagulation are permitted to enter the trial if anticoagulation can be safely managed to enable blood sampling) 6. Conditions in which blood sampling may increase risk of complications for the patients and/or investigator