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Managing symptoms and side effects

Symptoms and side effects vary from person to person – you may have none or only a few. Below are the most common symptoms and side effects experienced during treatment for CUP. You may experience others not mentioned here. Most symptoms and side effects can be relieved and some can even be prevented.

Many people with CUP worry that they will be in pain. Not everyone will experience pain, and those who do may find it comes and goes. Pain depends on the location of the cancer and its size.

There are many options for relieving pain. These include:

  • pain medicines, such as paracetamol; ibuprofen and other non-steroidal anti-inflammatory drugs; and opioids
  • an injection of pain-relieving drugs into the spinal column (epidural or spinal block)
  • relaxation therapies, such as massage, meditation, mindfulness meditation or hypnotherapy
  • treating the cause of the pain with chemotherapy, radiation therapy and surgery.

You may need to use more than one method to relieve pain. It may take time to find the right pain-control measure for you. If one method doesn’t work, you can try something else.

Treatments used to relieve pain

Chemotherapy, radiation therapy and surgery are common cancer treatments. They may also be used as palliative treatment for pain.

Chemotherapy – This treatment can shrink the size of a tumour that is pressing on nerves or organs and causing pain.

Radiation therapy – This treatment can be used to relieve most types of pain. The most common form of radiation therapy for pain is external beam radiation therapy. If cancer has spread to many places in the bone and is causing pain, another form of radiation therapy may be used. In this case, the doctor gives you an injection of a radioactive form of the metal strontium, which then settles in the bones near the cancer.

Surgery – Surgery can sometimes remove an isolated tumour. It can also be used to treat a serious condition such as a bowel blockage (obstruction) that is causing pain, or to reduce the size of the cancer and improve the effectiveness of chemotherapy and radiation therapy.

Pain management experts

Your GP or oncologist may be able to suggest effective medicine for your pain, but if you are still uncomfortable, you can ask to see a palliative care specialist. Good pain control is one of the major ways a specialist palliative care team can help someone whose pain is difficult to manage.

How and where the pain is felt, and how it affects your life, may change. Regular check-ups with pain management experts can help keep the pain under control. It’s better to take your pain medicine regularly, rather than waiting for the pain to occur.

Download our booklet ‘Understanding Cancer Pain’

For many people, extreme and constant tiredness (fatigue) can be the most difficult symptom to manage. It can be very distressing both for the person experiencing it and for those around them.

Tiredness can be caused by a range of things, such as:

  • the cancer itself or cancer treatments
  • low levels of red blood cells (anaemia) or high levels of calcium in the blood (hypercalcaemia)
  • drugs such as pain medicines, antidepressants and sedatives
  • infection
  • poor nutrition causing loss of weight and muscle tone
  • anxiety or low mood
  • lack of sleep
  • poorly managed pain.

Tips for managing fatigue

  • Pace yourself. Spread your activities throughout the day with rest periods in between.
  • Try to do gentle exercise. Research shows this reduces tiredness and preserves muscle strength. Even walking to the letterbox or getting up for meals can help.
  • Have a short nap of no more than 30 minutes during the day. This can refresh you without making it hard to sleep well at night.
  • Speak to an occupational therapist about ways to conserve energy.
  • Talk to your doctor if you often feel anxious or sad or if you are having trouble sleeping at night.

Download our fact sheet ‘Fatigue and Cancer’

Lack of appetite is a common problem faced by people with CUP. Some people don’t feel like eating because of stress from the diagnosis and treatment. The treatment may also change the way food tastes or smells. You might also not want to eat much if you are feeling sick (nauseated) or have a sore mouth. These problems can often be treated, so let your treatment team know.

You may go through periods of having no appetite. These may last a few days or weeks, or be ongoing. During these periods, it may help to have liquid meal substitutes. These are high-kilojoule drinks containing some of the major nutrients needed by your body. Drinking these may help keep your energy levels up during periods when your appetite is poor.

Tips for when you don’t feel like eating

  • Have small meals and snacks frequently throughout the day.
  • Use small dishes so food isn’t “lost” on the plate, e.g. serve soup in a cup.
  • Choose full-fat foods over low-fat, light or diet versions.
  • Use lemon juice, fresh herbs, ginger, garlic or honey to add more interesting flavours to bland food.
  • Sip fluids throughout the day. Add ice-cream, yoghurt or fruit to drinks to increase kilojoules.
  • If you have a sore mouth, eat soft food, such as scrambled eggs or stewed fruit.
  • Ask your dietitian if you can use nutrition and protein supplements to help slow weight loss and maintain muscle strength.

Download our booklet ‘Nutrition and Cancer’

Feeling sick in the stomach (nauseated) is an unpleasant symptom that may be caused by the cancer itself. Nausea can also be a side effect of some types of chemotherapy, but anti-nausea medicines can often prevent or manage this. Other causes of nausea include:

  • treatment with radiation therapy
  • stress or anxiety
  • too much or too little of a mineral in the blood, e.g. calcium
  • drugs used to control other symptoms, e.g. morphine for pain
  • the kidneys not working properly
  • an oral thrush infection, sometimes related to chemotherapy
  • a bowel blockage (obstruction) or constipation
  • increased pressure around the brain as a result of cancer in the brain or cancer affecting the fluid around the spinal cord.

Tips for easing nausea

  • Eat small meals as often as you can.
  • Eat cold foods, such as sandwiches, salads, stewed fruit or jelly.
  • Avoid strong odours and cooking smells.
  • Have food or drink that contains ginger, such as ginger ale, ginger tea or ginger cake.
  • Use stress-reduction techniques such as meditation or relaxation.
  • Talk to your doctor or nurse about anti-nausea drugs or treatments that can help relieve constipation.

Some people with CUP experience shortness of breath. Causes of breathlessness include:

  • fluid surrounding the lungs (pleural effusion)
  • an infection in the lungs
  • blood clot in the lung (pulmonary embolus)
  • pressure from the cancer itself or from a swollen abdomen
  • anaemia (low levels of red blood cells)
  • chronic breathing disorders, such as asthma or emphysema.

Treatment will depend on what is causing the breathlessness. You may need fluid drained from the chest (pleural tap) or medicine for an infection or other lung problem. A low-dose opioid medicine (also used for strong pain) is sometimes prescribed.

Tips to help your breathing

  • Use a fan or open a window to get a draught of air moving near your face. A battery-operated handheld fan may be helpful.
  • Sit up to ease your breathing or lean forward to rest on a table. Try sleeping in a more upright position.
  • Ask someone else to breathe in time with you so you can focus on slowing your breath to their pace.
  • Try relaxation or breathing techniques to see if they help. A physiotherapist can teach you these techniques, or you can listen to a meditation or
    relaxation recording.

Listen to our podcast episode ‘Managing Breathlessness when Cancer Is Advanced’

Featured resources

Cancer of Unknown Primary - Your guide to best cancer care

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Understanding Cancer of Unknown Primary

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This information is reviewed by

This information was last updated June 2020 by the following expert content reviewers: Prof Linda Mileshkin, Medical Oncologist, Clinical Researcher, Peter MacCallum Cancer Centre, VIC; Christine Bradfield, Consumer; Cindy Bryant, Consumer; Dr Maria Cigolini, Head, Department of Palliative Medicine, Royal Prince Alfred Hospital, and Clinical Lecturer, The University of Sydney, NSW; Mary Duffy, Advanced Practice Nurse and Nurse Coordinator, Lung Service, Peter MacCallum Cancer Centre, VIC; Karen Hall, 13 11 20 Consultant, Cancer Council SA; Dr Andrew Oar, Radiation Oncologist, Icon Cancer Centre, Gold Coast University Hospital, QLD; Dr Siobhan O’Neill, Medical Oncologist, Nelune Comprehensive Cancer Centre, NSW; Prof Penelope Schofield, Department of Psychological Sciences and the Iverson Health Innovation Research Institute, Swinburne University of Technology, and Head, Behavioural Science in Cancer, Peter MacCallum Cancer Centre, VIC; Frank Stoss, Consumer.