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Understanding Rare and Less Common Cancers

Page last updated: August 2024

The information on this webpage was adapted from Understanding Rare and Less Common Cancers - A guide for people with cancer, their families and friends (2024 edition). This webpage was last updated in August 2024.

Expert content reviewers:

This information was developed with the help of a range of health professionals and people affected by rare and less common cancers:

Emeritus Professor Phyllis Butow, Psychologist, The University of Sydney, NSW
Alison Danis, Consumer
Dr Michelle Harrison, Medical Oncologist, Chris O’Brien Lifehouse, NSW
Dr Damien Kee, Medical Oncologist, Austin Health and Peter MacCallum Cancer Centre, and Clinical Research Fellow, Walter and Eliza Hall Institute, VIC
Jess Pike, Senior Social Worker, Westmead Hospital, NSW
Trish Taylor, Consumer
Lesley Woods, 13 11 20 Consultant, Cancer Council WA

A cancer diagnosis is a life-changing event, and it is common to feel shocked or upset. Being told that the cancer is rare or less common may be particularly challenging.

A rare or less common (RLC) cancer may take longer and be more difficult to diagnose than other types of cancer. It may also be found at a late stage (advanced).

Any cancer affecting children and teenagers is considered rare. This is because it is unusual for younger people to have cancer. The same type of cancer found in an adult may not be considered rare.

Find out more about the risk factors, symptoms, diagnosis and treatment of specific rare and less common cancers including:

See the full A-Z list of cancer types

Get support

Call Cancer Council 13 11 20 for more information about rare and less common cancers. Our experienced health professionals can listen to your concerns, link you with services and send you our free booklets.

Contact cancer support

You can find many useful resources online, but not all websites are reliable. These websites are good sources of support and information:

About rare or less common cancer

An RLC cancer is a type of cancer that affects a small number of people.

Common cancers – Breast, bowel, prostate and lung cancer are examples of common cancers. Many people are diagnosed with these types of cancers.
Rare or less common cancers – Small bowel and gall bladder cancer are examples of rare or less common cancers. Few people are diagnosed with these types of cancers.

A cancer may be considered an RLC cancer when it:

is a subtype of a more common cancer (e.g. lymphoma is common; T-cell lymphoma is rare)
is a common cancer in an unusual part of the body (e.g. melanoma is common, but melanoma found in the eye, called ocular melanoma, is rare)
is in a part of the body where it is unusual to find cancer (e.g. the bones)
started in a different type of cell than usual
is more common to find this cancer type in the opposite sex (e.g. breast cancer in males)
is found in a person younger than expected (e.g. prostate cancer in someone under 40).

How common are rare cancers?

A rare cancer means fewer than 6 out of 100,000 people who are diagnosed with cancer have this type. A cancer is less common if 6–12 out of 100,000 people are diagnosed with this type.

There are a large number of different types of rare or less common cancers. Although only a small number of people are diagnosed with each RLC cancer type, together, they all add up to a large number.

Each year, it’s estimated about 52,000 Australians are diagnosed with a cancer that is considered to be rare or less common. Almost 1 in 3 people diagnosed with cancer will have an RLC cancer.

The number of people diagnosed with an RLC cancer is increasing. While the incidence of certain RLC cancer types may be on the rise, this overall increase in numbers may also be partly due to:

improvements in diagnosing different types of cancer
advances in testing (including genetic testing), and
early detection thanks to more accurate cancer screening.

Diagnosis

The process of diagnosing a rare or less common cancer may be quite different to that of diagnosing a common cancer. It may take longer to get an exact diagnosis, and involve more doctors and tests.

An RLC cancer type may be more difficult to diagnose because:

Some RLC cancers have symptoms that are less well known compared with the symptoms of more common cancers.
Symptoms may be similar to some common conditions. And these conditions are usually ruled out first, before a rare cancer is investigated.
Sometimes cancer develops in a person who is not expected to get cancer (e.g. due to their age or sex). This can lead to delays in looking for cancer.
Several tests may be needed, or more than one specialist involved, before getting a diagnosis.
Another diagnosis, or general cancer diagnosis may be made first, before the final diagnosis is confirmed (e.g. an initial finding of breast cancer, before a final diagnosis of metastatic triple negative breast cancer).
The pathologist may need to do a number of specialised tests on your tissue or blood sample, or they may have to send the sample to a specialist laboratory for testing.

Challenges in diagnosing an RLC cancer may mean it is found at a later stage. See Living with advanced cancer for more information.

The length of time it takes to accurately diagnose an RLC cancer can be upsetting and frustrating. You may also have tests to see if the cancer is hereditary, which can be worrying and stressful for your family.

For help with this, see Coping with a rare or less common cancer diagnosis.

“Being diagnosed with a rare cancer can make you feel totally isolated. When I began my treatment, I started meeting people who had also been diagnosed with a rare or less common cancer. I soon began to realise that although my cancer was rare, I wasn’t alone.” Nicole

Tests you may have

To find out what type of cancer you have, you may need several tests to look for the cause of your symptoms. Doctors will use the results of these tests to help work out the type of cancer you have and the best treatment for you.

Some specialised tests, including blood tests, may not be covered by Medicare or health insurance. Ask about the cost when booking or having these tests.

Physical examination – Your doctor may listen to your heart and lungs, look into your mouth or eyes, or feel your body to check for lumps, enlarged organs or other signs of cancer.
Scans and scopes – Tests might include an ultrasound and scans such as a CT (computerised tomography), a PET (positron emission tomography) or an MRI (magnetic resonance imaging). Tests could also include an endoscopic examination, which allows doctors to see inside your body using a small camera.
Blood tests – You will usually have blood tests to measure your white blood cells, red blood cells and platelets, and check how well your kidneys and liver are working. Blood tests can also look for infection and tumour markers (proteins produced by cancer cells). Urine tests may also check organ function or other markers.
Biopsy – To diagnose many cancers, a doctor may need to remove a sample of tissue from the affected area. The cells are then examined under a microscope by a specialist doctor called a pathologist. This is called a biopsy. The type of biopsy you have will depend on your symptoms and which part of the body is being checked.

Waiting for test results

Be prepared for results to take time

It may take days, a couple of weeks, or even longer to get your test results. This can be an anxious time.

You may feel like the future feels very uncertain, that something serious might be found, or that you have no control over what is happening to you. You may feel like you keep having tests and not getting any answers.

Try to focus on other things

There is no right or wrong way to deal with the anxiety of waiting.

Some people find it helpful to keep doing their usual activities, such as going to work, as this is a good distraction from worrying about the test results. But others may find it hard to concentrate on anything else.

Let others know how you are feeling

While you are waiting, it might help to talk to a close friend or relative about how you feel.

You can also call Cancer Council 13 11 20, where experienced health professionals can listen to your concerns, answer questions about cancer, and provide you with helpful resources and links to support services.

Molecular and genetic testing

Every cell found in the human body has about 20,000 genes, which tell the cell what to do and when to grow and divide. Cancer starts because of changes to the genes (known as mutations).

Some people are born with a gene change that increases their risk of cancer (inherited faulty gene), but most gene changes that cause cancer happen during a person’s lifetime (acquired gene changes).

For some people with an RLC cancer, doctors may recommend extra tests to look for acquired gene changes (molecular tests) or inherited gene changes (genetic tests).

For some cancers, molecular or genetic tests may help make a diagnosis, or guide your doctor to the most effective treatment.

Molecular testing

You may be offered extra tests on a biopsy sample known as molecular or genomic testing.

This looks for gene changes and other features in the cancer cells that may help your doctor decide which treatments to recommend.

Medicare may or may not cover molecular testing, depending on the cancer type.

These tests can be expensive, so check the cost and how helpful they would be. If you are having molecular testing as part of a clinical trial, the costs may be covered.

Genetic testing

If your doctor suspects the RLC cancer is linked to an inherited or faulty gene, they may refer you to a family cancer clinic for more tests and genetic counselling.

These tests, known as genetic or germline tests, may help your doctor work out what treatment to recommend.

The tests can also provide important information for your blood relatives, who may also have inherited a faulty gene.

Genetic counselling can help you understand what tests are available, and what results mean for you and your family. You may also want to be included on a hereditary or familial cancer registry in your state.

Medicare covers some genetic tests, but others have a cost. Ask your treatment team what you will pay.

Question checklist

It is important to ask your doctors questions, especially if you feel confused or uncertain. You may want to make a list of questions before appointments and include some of these questions:

What type of cancer do I have? Why is it considered a rare or less common cancer?
Where is the cancer and has it spread? If so, where to? How fast is it growing?
Can you explain the test results to me?
What are my treatment options?
Is there a patient organisation or support group for the type of cancer I have?
How many patients with this type of cancer have you treated before?
Can you give me an idea of my prognosis?
How often will I need check-ups?
If the cancer returns, how will I know? What further treatment could I have?