The specialist will arrange extra tests to work out whether you have primary or secondary cancer. If the tests show that the cancer is secondary, more tests will be done to try to find the primary cancer. The tests you have depend on your health and symptoms, the location of the secondary cancer and the suspected location of the primary cancer.
If the tests find where the cancer started, the cancer is no longer an unknown primary. It will then be treated like the primary cancer type. For example, bowel cancer that has spread to the liver will be given the treatment for advanced bowel cancer.
Tests used to find where the cancer started
| blood and urine tests | samples of your blood and urine are sent to a laboratory to be checked for abnormal cells and chemicals called tumour markers |
| biopsy | a tissue sample is taken from a tumour, enlarged lymph node or bone marrow and sent to a laboratory for examination; tests on the sample can suggest the primary site |
| endoscopy | uses an instrument to look inside the body and take small tissue samples |
| imaging tests | x-rays, ultrasounds and and other scans create images of the inside of the body; PET-CT scans have been shown to help find the primary site in new cases of CUP |
The diagnosis and treatment of CUP can be complex and you might need to travel to a specialist centre. Call Cancer Council 13 11 20 to ask about patient travel assistance that may be available to you.
→ READ MORE: Blood and urine tests
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Key resource
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More resources
Prof Chris Karapetis, Network Clinical Director (Cancer Services), Southern Adelaide Local Health Network, Head, Department of Medical Oncology, and Director, Clinical Research in Medical Oncology, Flinders Medical Centre and Flinders University, SA (Clinical review); Dr Amey Aurangabadkar, Radiologist, Illawarra Radiology Group, NSW; Clare Brophy, Consumer; Prof Katherine Clark, Clinical Director of Palliative Care, NSLHD Supportive and Palliative Care Network, Northern Sydney Cancer Centre, Royal North Shore Hospital, NSW; Prof Wendy Cooper, Senior Staff Specialist, Tissue Pathology and Diagnostic Oncology, NSW Health Pathology, Royal Prince Alfred Hospital, NSW; A/Prof Richard Gallagher, Head and Neck Surgeon, Director of Cancer Services and Head and Neck Cancer Services, St Vincent’s Health Network, NSW; Dr Chloe Georgiou, Oncology Research Fellow, Australian Rare Cancer Portal, and Oncology Trials Fellow, Bendigo Health Cancer Centre, VIC; Dr Susan Harden, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC; Justin Hargreaves, Medical Oncology Nurse Practitioner, Bendigo Health Cancer Centre, VIC; Dr Laura Kirsten, Principal Clinical Psychologist, Nepean Cancer Care Centre, NSW; Prof Linda Mileshkin, Medical Oncologist, Peter MacCallum Cancer Centre, VIC; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA.
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