Cancer of unknown primary


Treating cancer of unknown primary

Page last updated: October 2024

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When tests have been unable to find the primary cancer, you will be given a diagnosis of CUP. This is often a difficult time and it can be hard to accept that the primary site cannot be found.

On the other hand, you may feel relieved that the tests are over and that the focus can now be on treating the cancer.

The treatment recommended by your doctors will depend on:

  • where the secondary cancer is in the body and how far it has spread
  • where they think the cancer started
  • how quickly the cancer seems to be growing
  • how you are feeling (your symptoms)
  • your general health, age and treatment preferences
  • what treatments are currently available and whether there are any newer treatments available on clinical trials (see previous page)
  • the aim of treatment (whether to remove as much of the cancer as possible, slow the cancer’s growth or relieve symptoms).

The most common treatment for CUP is chemotherapy, and many people also have radiation therapy and surgery. Some cancers may respond to hormone therapy, targeted therapy or immunotherapy. Your doctor may suggest a combination of treatments.

Your guide to best cancer care

A lot can happen in a hurry when you’re diagnosed with cancer. The guide to best cancer care for liver cancer can help you make sense of what should happen.

It will help you with what questions to ask your health professionals to make sure you receive the best care at every step.

Read the guide

Chemotherapy

Chemotherapy uses drugs to kill cancer cells or slow their growth. Medical oncologists and some specialists prescribe chemotherapy to shrink a cancer and relieve symptoms. It can be used with radiation therapy or surgery to try to kill a collection of cancer cells in the body.

How chemotherapy is given

Side effects of chemotherapy

Hormone therapy

Hormones are substances that occur naturally in the body. Some cancers depend on hormones to grow (e.g. oestrogen may help breast cancer grow).

Hormone therapy aims to lower the amount of hormones in the body in order to slow or stop the cancer’s growth. The treatment may be given as tablets you swallow or injections.

If tests show that the CUP may have started as a cancer that is hormone dependent, your doctor might suggest hormone therapy. It is sometimes used with other treatments.

Side effects of hormone therapy

Learn more

Targeted therapy

Targeted therapy is a type of drug therapy that attacks specific features of cancer cells to stop the cancer growing and spreading. Many targeted therapy drugs are given by mouth as tablets, but some are given by injection.

Only a small number of CUP tumours will be suitable for targeted therapy. Your doctors will need to test the cancer to see if the cells have a particular cell change that is helping the cancer grow.

Side effects of targeted therapy

 

Immunotherapy

Immunotherapy uses the body’s own immune system to fight cancer. Sometimes the results of specialised tests on a CUP tumour may suggest that immunotherapy could help to treat the cancer.

More evidence is needed to tell whether immunotherapy works for CUP, so it isn’t funded on the Pharmaceutical Benefits Scheme (PBS) yet.

However, immunotherapy may be accessed if tests strongly suggest you have one of the other cancer types that are funded on the PBS. Immunotherapy may also sometimes be accessed through clinical trials.

Learn more

Radiation therapy

Radiation therapy, also known as radiotherapy, uses a controlled dose of radiation to kill or damage cancer cells. The radiation is usually in the form of x-ray beams.

Most people with CUP have radiation therapy to relieve symptoms, such as pain, bleeding, difficulty swallowing, bowel blockages, shortness of breath, and tumours pressing on blood vessels or nerves or within bones.

Having radiation therapy

Chemoradiation

Side effects of radiation therapy

Surgery

Surgery removes cancer from the body. It is mostly used if cancer is found at an early stage. If CUP has already spread to a number of places in the body, surgery may not be the best treatment. If surgery is used, it may remove only some of the cancer.

Surgery is often followed by radiation therapy or chemotherapy to kill or shrink any cancer cells left in the body. If the cancer is found only in the lymph nodes in the neck, underarm or groin, it may be possible to remove all of it with an operation.

This is called a lymph node dissection or lymphadenectomy. Sometimes surgery can help with symptoms – for example, to relieve pain caused by the tumour pressing on a nerve or organ.

Side effects of surgery

Learn more

“There is still a life to be lived and pleasures to be found and disappointments to be had. Living with advanced cancer is a different life, not just a journey towards death.” Julie

Palliative treatment

Most people with CUP receive palliative treatment. This is treatment that aims to slow the spread of cancer and relieve symptoms without trying to cure the disease.

Cancer treatments such as surgery, radiation therapy, chemotherapy or other medicines are often given palliatively. It is possible that palliative treatment may make you feel better and also help you live longer.

You might think that palliative treatment is only for people at the end of their life, but it may help at any stage of advanced cancer. It is about living for as long as possible in the most satisfying way you can.

What is palliative care?

Get support

Many people feel shocked and upset when told they have cancer. It can be even more distressing if the cancer has spread and the original (primary) site cannot be found.

Cancer Council's experienced nurses can help you connect with other people who are living with advanced cancer, and provide you with information about the emotional and practical aspects of living with CUP.

Contact cancer support

Understanding Cancer of Unknown Primary

Download our Understanding Cancer of Unknown Primary booklet to learn more and find support.

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