Treatment options


Treatment and care of people with cancer is usually provided by a team of health professionals, both medical and allied health, called a multidisciplinary team. [3]

Because the primary cancer is unknown, treatments may differ from person to person. Treatment for cancer of unknown primary depends on: 

  • the type of cell that the cancer started from  
  • where it has spread to in the body 
  • the number of organs that the cancer has spread to 
  • your signs and symptoms of cancer 
  • the results of your tests and scans 
  • your general health 
  • your personal preferences. 

Treatment options may include surgery, chemotherapy, radiation therapy, hormone therapy and targeted therapy. 


If the cancer of unknown primary is a solid tumour, your doctor may try to remove it with surgery. Your doctor may also remove lymph nodes. Because the tumour is of unknown primary, you will likely need other treatments other than just surgery, to try to destroy any remaining cancer cells in the body. 


Most cancers of unknown primary will be treated with chemotherapy. This is because chemotherapy is often used for cancers that have metastasised (spread), because chemotherapy can treat many different types of cells and organs at once. 

Chemotherapy may be used to make the tumour smaller before surgery (neoadjuvant treatment) or remove any remaining cancer cells after surgery (adjuvant treatment). 

For more information see chemotherapy

Radiation therapy

You may receive radiation therapy for cancer of unknown primary. 

Radiation therapy may also be used to make the tumour smaller before surgery or to remove any remaining cancer cells after surgery. 

Radiation therapy may also be used to relieve symptoms of the cancer, such as pain. 

Hormone therapy[4]

Hormone therapy may be useful if there is an indication that the primary cancer is breast or prostate cancer. These are cancers that respond to oestrogen (such as some breast cancers) or androgens (such as many prostate cancers). Hormone therapy either blocks oestrogen or androgen receptors on the cancer cells, or lowers the levels of hormones in your body as a way to slow cancer growth. 

Targeted therapy[5]

Targeted therapy may be used if your cancer cells have a certain characteristic for the therapy to target. Laboratory testing is done to check if there are any targeted therapies that may benefit you.