Important information

A person with a suspected cancer of unknown primary should be referred to a specialist who is a member of a relevant multidisciplinary team. 

All specialists listed on Canrefer are members of a multidisciplinary team.


What is cancer of unknown primary?

Cancer of unknown primary (CUP) is a term used when cancer has been diagnosed but the original (primary) place where the cancer started cannot be found. In people with a CUP, symptoms are caused by a cancer that has spread (metastatic cancer).

Approximately 5% of cancer diagnoses are cancers of unknown primary.

Graphic of a body with a question mark


What tests are needed?

Common tests used to diagnose cancer of unknown primary include:

  • physical examination
  • blood tests
  • urine and/or faeces tests
  • imaging - X-ray, ultrasound, CT scan, MRI scan and/or PET scan
  • biopsy
  • endoscopy.


What treatment options are there?

Treatment for cancer of unknown primary may include one or more of the following:

  • surgery
  • chemotherapy
  • targeted therapy
  • hormonal therapy
  • radiotherapy.

If treatment is specialised and complex, patients may need to travel to have a part of their treatment. The local health district will have an arrangement in place for this.


How common is cancer of unknown primary in NSW?

Cancer of unknown primary was diagnosed in:

  • 2015
    957 people in NSW
  • 2014
    1037 people in NSW
  • 2013
    1087 people in NSW
Data source: Cancer statistics NSW portal (sourced from Institute Data Warehouse, Cancer Institute NSW. Available at:


Last updated: 22 February 2019.