Before CUP is diagnosed, you will usually see your GP, who will examine you, send you for tests and refer you to a specialist doctor. The specialist will ask you about your general health and any previous medical problems.
This section describes the various tests that your doctors may arrange. Initially, the purpose of the tests is to work out whether you have cancer, and whether it is primary or secondary. If the tests show that the cancer is secondary, you will have further tests to try to find the primary cancer.
The recommended tests for CUP vary depending on your general health, the location of the secondary cancer and the presumed location of the primary cancer. Often several different tests are needed to look for the primary cancer. You may have questions about the tests your doctor suggests – see our Question Checklist.
These tests will look for abnormal cells and measure the levels of certain chemicals (tumour markers).
In this procedure, samples of tissue are removed from a secondary tumour or an enlarged lymph gland and sent to a laboratory for examination under a microscope.
This procedure uses an instrument called an endoscope to look inside the body and remove small tissue samples.
X-rays, ultrasounds and CT, PET-CT, MRI and bone scans create images of the inside of the body.
If these tests find where the cancer started, the cancer is no longer an unknown primary and is treated like the primary cancer type.
A complete blood count checks the levels of red blood cells, white blood cells and platelets. Urine may also be tested for any abnormal cells or substances and to see if there are any problems with organs such as the kidneys or bladder.
Tumour markers are chemicals made by some cancer cells. Some are found in the blood, but others are found in urine or other body fluids. Your symptoms and sex help the doctor decide if it would be helpful to check for any of these markers. Tumour markers include:
A biopsy is the removal of a tissue sample for examination in a laboratory. It is usually the most important test in the diagnosis of CUP because it can show what type of cell has changed, and this indicates where in the body the cancer may have started.
The tissue sample is often removed under local anaesthetic, but it may sometimes be removed under general anaesthetic. You may have one of the following types of procedures:
At the laboratory, a specialist doctor called a pathologist will run a series of stains on the sample to see if they can work out the type of cancer. These stains may show specific changes in the cells or highlight proteins (antigens) that are linked to various types of cancer. It may be a week or more before results are available.
Some labs can test a biopsy for genetic changes or patterns linked to specific types of cancer. These may be called cytogenetic tests or gene expression-based profiling (GeBP). As it is not yet clear how useful these tests are, their availability is still limited.
A biopsy may not be helpful if the cancer is too difficult to reach or if you’re too unwell for the procedure. Talk to your doctor if you have any questions about this.
This procedure is used to look inside the body for any abnormal areas. A thin, flexible tube with a light and camera on the end, called an endoscope, is inserted through a natural opening (such as the mouth, anus or vagina) or through a small cut made by the surgeon. The endoscope has a small cutting instrument on the end so a biopsy can be taken at the same time if something suspicious is seen. The most common types of endoscopies are listed in the table below.
|Type of endoscopy
|| Part of the body tested
||Where the tube is inserted
||lungs or respiratory tract|| mouth or nose
||colon (large bowel)
||vagina and cervix
|| organs are viewed from outside the vagina
||stomach and small bowel
||stomach, liver, female reproductive organs
|| small cuts in the abdomen
||larynx (voice box)
||colon (large bowel)
||lungs|| small cut in the chest
Prognosis means the expected outcome of a disease. You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for any doctor to predict the exact course of your disease.
To come up with your prognosis, your doctor will consider test results, the type of CUP you have, the rate and depth of tumour growth, how well you respond to treatment, and other factors such as your age, fitness and medical history.
Although most cancers of unknown primary can’t be cured, treatment can keep some cancers under control for months or years. For example, some people with a localised deposit of CUP (e.g. in a lymph node in the neck) are able to achieve long-term control, or sometimes even a cure, with surgery or high-dose chemoradiation (a combination of chemotherapy and radiotherapy).
Whatever the prognosis, palliative treatment can relieve symptoms such as pain to improve quality of life. It can be used at any stage of advanced cancer.
"I’ve been having palliative treatment for five years. I’m not trying to get rid of the disease, just keeping it under control. My quality of life is excellent." - Kate
"At the time of my diagnosis, I was working as a senior lawyer. One morning, I was on the phone to a client and looking out the window. I was running a hand over my chin when I felt a lump. I actually said to the client, 'I’ve just felt this lump, so I’m going to see my GP. Goodbye.'
"I had to have a needle biopsy the next day and the results of that were significant. It was squamous cell carcinoma and it was metastatic.
"The doctors did another couple of biopsies to look for the primary, but they couldn’t find it. They guessed the cancer had started in my mouth, but I had a fair complexion and red hair, so it might also have started somewhere on my skin.
"I had surgery to take out most of my molars, then more surgery to remove all the lymph nodes down one side of my neck.
Even though we hadn’t found the primary cancer, I talked about the treatment options with my doctors and we agreed to forge ahead. I was 51 and fit, so we decided on a broad approach with a combination of strong chemotherapy and radiotherapy.
"The cancer diagnosis knocked me for six. I went into a deep black hole. The fact that it was CUP didn’t affect me at the time – I didn’t grasp what metastatic meant.
"I like to think that I’m a fairly optimistic and together person, but after the treatment was over, I struggled with anxiety about the cancer recurring. The fact that the primary cancer wasn’t found added to that anxiety – it was an extra element.
"I ended up seeing a psychiatrist about a year after my treatment, but it would have been better to get that sort of help earlier."
Reviewed by: A/Prof Linda Mileshkin, Medical Oncologist, Peter MacCallum Cancer Centre, VIC; Dr Sarwan Bishnoi, Medical Oncologist, Adelaide Cancer Centre, SA; Dave Clark, Consumer; Dr Jan Maree Davis, Area Director, Palliative Care Service, Calvary Health Care and St George Hospital, NSW; Linda Tompsitt, Cancer Nurse 13 11 20, Cancer Council WA; Catherine Trevaskis, Gastrointestinal Cancer Specialist Nurse, The Canberra Hospital, ACT.