Treating unknown primary cancer

Sunday 1 May, 2016

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On this page: ChemotherapyRadiotherapyHormone therapy | Surgery | Palliative care | Linda's story | Key points


When tests have been unable to find the primary cancer, a diagnosis of CUP is given. This is often a difficult time and it can be hard to accept that the primary cannot be found. Some people may feel relieved that the tests are over and that the focus can now be on treatment options.

Your doctors will recommend treatment based on:

  • what will give you the best outcome
  • the location of the secondary cancer
  • test results
  • how likely it is to be a certain type of cancer
  • your general health
  • your preferences.

The most common treatment for CUP is chemotherapy. You may also have radiotherapy, hormone therapy, surgery or targeted therapies. Different types of treatment may be combined.

For many people, CUP is diagnosed at an advanced stage and treatment is unlikely to cure it. However, treatment may be able to control the cancer and improve your symptoms. It is possible that treatment may make you feel better and also help you live longer. This is called palliative treatment.

"I found it complex to talk to people about my cancer. I can explain it, but they find it hard to understand. It does seem incomprehensible to have a cancer that has spread but no named starting point." - Jane

Chemotherapy

Chemotherapy is the treatment of cancer with anti-cancer (cytotoxic) drugs. It aims to kill cancer cells while doing the least possible damage to healthy cells.

Medical oncologists and sometimes other specialists prescribe chemotherapy to shrink tumours, and to relieve symptoms caused by the cancer. It can also be used in combination with radiotherapy or surgery to try to kill any local collections of cancer cells in the body. Different cancer cells respond to different chemotherapy drugs. People with CUP may have a combination of drugs.

Generally, chemotherapy is given by injecting the drugs into a vein (intravenously), often through a drip. The drugs circulate through the bloodstream and can kill cancer cells throughout the body (systemic treatment). Some types of chemotherapy are taken by mouth as tablets.

Chemotherapy cycles

Chemotherapy is given in courses known as cycles. Each cycle consists of a treatment period followed by a recovery period. You may be able to have treatment as an outpatient, but sometimes a short stay in hospital is required.

The number of treatment cycles you have depends on your situation. With CUP, it is recommended that your doctors test how the cancer responds to the chemotherapy after two or three cycles. This will allow you to weigh up the benefits of continuing against the effect on quality of life.

Side effects of chemotherapy
  • Most chemotherapy drugs cause side effects. Different drugs have different side effects. Your medical oncologist or nurse will discuss them with you.
  • The most common side effects include feeling sick (nausea), vomiting, mouth sores, tiredness, loss of appetite, diarrhoea, and some thinning or loss of hair from your body and head. Most side effects are temporary, and can be prevented or reduced.
  • Chemotherapy weakens the immune system, making it harder for your body to fight infections. You will have regular blood tests to check your immune system. If your temperature rises to 38°C or above while receiving chemotherapy, contact your medical team or hospital immediately.
For more information see Understanding Chemotherapy or call Cancer Council 13 11 20.

Radiotherapy

Radiotherapy uses x-ray beams to kill cancer cells. For most people with CUP, the purpose of radiotherapy is to relieve symptoms, such as bleeding, difficulty swallowing, breathlessness, blocking of the intestines, compression of blood vessels or nerves by tumours, and pain caused by cancer spreading to the bones.

You will have an x-ray of the treatment area to help with planning your treatment. To ensure that the same area is treated each time, the radiation therapist will make a few small dots (tattoos) on your skin that may be temporary or, in some cases, permanent. Talk to your radiation oncologist if you are concerned about the tattoos.

You may have external or internal radiotherapy. External radiotherapy is given from a machine outside the body. For internal radiotherapy, a radiation source is put inside the body on or near the cancer. Radiotherapy treatments are painless. The total number of treatments and their duration will depend on your situation. You might need only a couple of treatments, or you may need them every weekday for several weeks.

Some people with localised squamous cell carcinoma in the lymph nodes of the neck may have a combination of chemotherapy and radiotherapy (chemoradiation) to try to treat the disease.

Side effects of radiotherapy
  • The side effects of radiotherapy depend on the area of the body being treated and the dose of radiation.
  • Common side effects include nausea, loss of appetite, diarrhoea, tiredness and shortness of breath. It can also make your skin dry and itchy in the area treated. Your skin may look red or sunburnt.
  • Side effects tend to develop as you go through treatment, and most improve or go away after treatment is finished. Talk to your doctor or nurse about ways to manage them.

For more information see Understanding Radiotherapy or call Cancer Council 13 11 20.

Hormone therapy

Hormones are substances that occur naturally in the body, but some cancers are stimulated by particular hormones – for example, breast cancer by oestrogen. Hormone therapy uses hormones made in a laboratory (synthetic) to block the effect of the natural hormones that are helping the cancer to grow.

If tests show that the CUP may have started as a cancer that is hormone dependent, your doctor might suggest hormone therapy. The treatment may be given as tablets or injections. It is sometimes used with other treatments, e.g. to shrink a tumour before surgery.

Side effects of hormone therapy
  • The side effects vary depending on the hormones you are given.
  • General side effects include tiredness, nausea, diarrhoea, constipation, appetite changes, weight gain, mood changes, hot flushes, pain in the joints, thinning of the bones, hot flushes (for women) and erection problems (for men).
Targeted therapies

Targeted therapies are a new group of drugs that destroy or stop the growth of cancer cells while minimising harm to healthy cells. It is not yet clear how useful targeted therapies are for CUP, but clinical trials are testing combinations of chemotherapy and targeted therapies. Most targeted therapies are injected into a vein, but some are given by mouth as tablets.

Surgery

Surgery is a common treatment for many types of cancer if they are found at an early stage. With CUP, the cancer has already spread beyond the site where it started, so surgery may not be used as a treatment or it may remove only some of the cancer.

If the cancer is found in only one area (e.g. in the lymph nodes in the neck, underarm or groin), it may be possible to remove it with an operation. Surgery may be followed by radiotherapy or chemotherapy to kill any cancer cells left in the body. Sometimes surgery can help with symptoms – for example, to relieve pain caused by the cancer pressing on a nerve or organ.

Side effects of surgery
  • Some people experience pain after surgery but this is often temporary. Talk to your doctor or nurse about painkillers.
  • If you’ve had lymph nodes removed, you may develop lymphoedema. This is swelling caused by a build-up of fluid in part of the body, usually in an arm or leg. For more information, speak to your nurse or visit lymphoedema.org.au.

Palliative treatment

Many people with CUP receive palliative treatment, which can be used at any stage of advanced cancer to improve quality of life. Palliative treatment aims to slow the spread of cancer and manage symptoms without trying to cure the disease. It is one aspect of palliative care, in which a team of health professionals aim to meet your physical, emotional, practical and spiritual needs. Palliative care is not just end-of-life care and does not mean giving up hope. Rather, it is about living for as long as possible in the most satisfying way you can. It also provides support to families and carers.

It is best to make contact with the palliative care team as early as possible. You can find out what the different team members do and work out which services might be useful now or in the future. Call Cancer Council 13 11 20 for free booklets about palliative care and living with advanced cancer, or download digital versions from your local Cancer Council website.

Linda’s story

"My husband, Steve, was diagnosed with cancer of unknown primary. It started off with a sore back. Then he had trouble walking and the pain became unbearable. Steve had some scans, which showed a mass. He was referred to the hospital for further tests.

They never found the location of the primary cancer; they only found the secondary tumours on Steve’s spine and in his lungs and liver. The doctors said the cancer was inoperable and untreatable. He had chemotherapy and radiotherapy to relieve his pain and to reduce the size of the secondary tumour on his spine.

I cared for Steve at home but took him to hospital for chemo. I was able to give him injections to help control his pain. We also had an excellent palliative care nurse visit every day."

Key points

  • Treatment can help control the symptoms of CUP, but it may not cure the disease.
  • CUP treatment may include chemotherapy, radiotherapy, hormone therapy, surgery and targeted therapies. The best treatment for you will depend on the type of cancer cell, the suspected primary site, the location of the secondary cancer(s), and your general health.
  • Chemotherapy treats cancer with drugs. Most of the drugs used for chemotherapy cause side effects, such as nausea, vomiting, mouth sores, tiredness, loss of appetite, diarrhoea and hair loss. There may also be an increased risk of infections. Side effects depend on what kinds of drugs you are given.
  • Radiotherapy treats cancer by using x-ray beams to kill cancer cells. It is painless but radiotherapy may cause side effects such as skin irritation or shortness of breath. Other side effects include nausea and tiredness.
  • Hormone therapy is sometimes used to treat CUP by slowing the growth of the cancer or shrinking it.
  • Surgery may be used to remove lymph nodes in the neck, underarm or groin. It’s not always a treatment option for CUP, and sometimes only part of the cancer can be removed.
  • Targeted therapies are a new group of cancer drugs. Clinical trials are testing their usefulness for CUP.
  • The goal of palliative treatment is to manage symptoms to improve quality of life. If possible, get in touch with the palliative care team early.

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.