Rare cancers

Rare cancers affect a small number of people. Doctors might also call a cancer rare if it starts in an unusual place in the body. Or if the cancer is an unusual type and needs special treatment.

What is a rare cancer?

There are more than 200 different types of cancer, including leukaemias and lymphomas. They develop from the different types of cells in different parts of the body. Cancers are often classed as common, less common and rare.

Breast, prostate, lung and bowel cancer are the top 4 most common cancers. Examples of less common cancer include:

  • melanoma skin cancer
  • kidney cancer
  • brain tumours
  • non-Hodgkin lymphoma
  • pancreatic cancer

Experts have different ideas about what makes a cancer rare. In Europe and the UK experts say it is rare if fewer than 6 in 100,000 people are diagnosed each year. This makes up about 24 out of every 100 (about 24%) of all cancer cases diagnosed in Europe and the UK per year. This also includes children and young people’s cancers.

Other experts say that a type of cancer is rare if doctors diagnose fewer than 2 in 100,000 people each year.

Subtypes of more common cancers

Doctors and researchers are learning more and more about cancer. They are looking at particular features that divide some cancers into subtypes. They think that some of these subtypes are rare.

Doctors treat some rare subtypes in the same way as other cancers of that type. Other subtypes get treated differently. For example, they treat small cell cancer of the cervix in a different way to most other cervical cancers.

Why can it take longer to diagnose rare cancers?

It can take longer for doctors to diagnose a rare type of cancer because the symptoms might be unusual and less recognisable than more common types. You might also need to have more tests than people with more common cancers.

The tests first work out whether you have a cancer. Then they find out exactly what type it is.

The pathologist Open a glossary item might need to do a number of different tests on your biopsy sample or blood test. Or they might need to send the sample to a specialist laboratory for examination. This might be for a specialised test to find out your type of cancer. Depending on the test, it could take quite a few days and sometimes weeks to carry out and get the results. This means it could take longer to reach a diagnosis.

For very rare types of cancer your doctor may need to get other expert advice from across the country or world to talk about your symptoms and test results before they can give you any information. This can be quite frustrating and worrying as you don’t know what you are dealing with. You might feel like your doctor is hiding something, but it’s all part of them trying to work out what they can do to help you.

Once they confirm your diagnosis they then need to work out a treatment plan. They may refer you to a specialist cancer centre. They may need time to research and speak with other professionals who have treated people with this type of rare cancer.

Questions to ask your doctor about getting diagnosed with a rare cancer

You are likely to have a lot of questions to ask your doctor. It might help to write them down so you don't forget. It’s also a good idea to take someone with you like your partner, family member or a close friend. They will help provide you with support and help remember what the doctor has said.

Your doctor might not be able to answer all your questions straight away. They may need the results of some tests first or want to ask other professionals for advice.

Here is a list of things you could ask:

Before you have a diagnosis:

  • When will you know if I definitely have cancer?
  • Which tests do I need?
  • How long will it take before I get the results?
  • How will I be told the results?
  • Do you have someone I can contact while I am waiting for the results to come back?
  • What emotional support can I get?

After you have a diagnosis:

  • What type of cancer do I have?
  • Where is the cancer?
  • Are there signs the cancer has spread?
  • What happens if the results show the cancer has spread? Do I need other tests?
  • What chance do I have of surviving this cancer?
  • How rare is this cancer?
  • If I have a rare type of cancer, will the treatment be different from the commonest type of that cancer?
  • When will I start treatment?
  • What are the expected side effects of this treatment?
  • What if I don’t have treatment?
  • How will we know the treatment is working?
  • How long is the treatment?
  • Where do I go for treatment?
  • When am I likely to see you again?
  • Should I get a second opinion? How do I get the second opinion?
  • What am I likely to feel like during treatment? Will I be able to work or look after my children?
  • What help is available to me financially?
  • Are there support groups, or anyone else I can talk to about this type of cancer?

Getting a second opinion

You might feel that you would like to get an opinion from a second doctor before deciding about your treatment. If so, ask your specialist to refer you to a doctor specialising in this cancer.

It’s better to arrange a second opinion through your specialist because they can send all your notes and test results with you.

Ask your doctor how they came to this diagnosis. With rare cancer they will have discussed your case with other health professionals to work out the best treatment plan for you. This may mean you have probably had a second and third opinion without even knowing.

Do remember that a second opinion does not necessarily mean that the second doctor will take over your care. Your treatment will usually still be managed by your original specialist.

Treatment for rare cancer

A team of doctors and other professionals discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).

The treatment you have depends on several factors including:

  • where the cancer is
  • how big it is and whether it has spread (the stage)
  • how abnormal the cells look under a microscope (the grade)
  • your general health and level of fitness

Your doctor will discuss the treatment, its benefits and the possible side effects with you.

Some of the types of treatments for rare cancers include:

  • surgery
  • chemotherapy
  • radiotherapy
  • hormone therapy
  • targeted cancer drugs
  • immunotherapy
  • stem cell or bone marrow transplant
  • having treatment as part of a clinical trial

You may have more than one of these types of treatments. Your doctor and nurse are the best people to speak to about your particular cancer.

You might also be able to find information for your type of cancer from our A to Z list. 

Preparing for treatment

There are things you can do to help you feel more in control of your physical and mental health during this time.

Research says that focusing on certain lifestyle changes in whatever time you have before treatment starts can help you cope better with its side effects and improve your long term health.

In the hospital, preparing for treatment is also called prehabilitation or prehab.

Research into rare cancers

Researchers around the world are looking at better ways to diagnose and treat rare cancers.

Ask your cancer specialist or specialist nurse about trials. They might be part of a research group if they have particular expertise in your type of cancer. 

You can look at our searchable database if you are looking for a trial for a rare cancer in the UK. You can choose from the list of cancer types, or type the name of your cancer into the search box. Talk to your specialist if there are any trials that you think you might be able to take part in.

Challenges in research for rare cancer

There might be fewer clinical trials for rare types of cancer than for more common types of cancer. This is because it is hard to organise and run trials for rare cancers. For example, it can take a long time to recruit the number of patients needed.

Getting enough patients is critical to the success of a trial. The results wouldn't be powerful enough if the trial involves too few people. For example, results won't be able to prove whether one type of treatment is better than another.

Our research into rare cancer

We’ve contributed to several advances for people with rare cancers. We ran some of the first trials for people with uveal melanoma and neuroendocrine tumours. And we set up and continue to support the International Rare Cancers Initiative (IRIC), which is developing clinical trials worldwide to find new treatments for rare cancers.

The International Rare Cancers Initiative (IRCI)

The IRCI aims to develop more research into new treatments for people with rare cancers. They are focusing on certain types of cancer including:

  • anal cancer that has come back or spread
  • rare melanoma
  • penile cancer
  • salivary gland cancer
  • small bowel adenocarcinoma
  • sarcoma of the female sex organs, such as sarcoma of the womb
  • merkel cell carcinoma (a type of skin cancer)

The IRCI designs trials that involve several countries, including the UK. This means that more people will be available to enter the trials. 

Research into genomics

Genomics means to study the complete set of genes Open a glossary item (genome). The genome is made of DNA Open a glossary item (genetic code) and is the body’s instruction manual. It tells the body how to make, run and repair itself. Almost every cell in the human body has a complete set of genes.

Scientists link cancer to changes in the genome. Researchers are looking at cancer cells, as well as healthy cells in each person.

The Department of Health and Social Care is running the 100,000 Genome project. Its role is to understand what genes play in health and disease. An area of focus within this project is cancer, including rare cancer. 

There are other research studies looking at rare cancers and those that affect people at a young age to find out more about cancer genetics and if they can develop further tests.

Rare Cancers Europe

Rare Cancers Europe is a partnership between:

  • a variety of different research organisations
  • professional societies
  • charities
  • rare cancer networks

This initiative was set up to raise the awareness of rare cancers and their work includes:

  • improving the quality of clinical trials into rare cancers
  • increasing the number of trials available
  • the development of more successful treatments for rare cancers

Coping with a rare cancer diagnosis

Many people feel isolated if they have a rare type of cancer. It might take longer to get a diagnosis and to start treatment. And you may not know anyone else with this type of cancer.

You might need to go to a specialist hospital for treatment. This could involve travelling a bit further than your local hospital. But it can be reassuring to know that a specialist team is caring for you. You are also more likely to meet someone else with your cancer type.

Give yourself time to cope. Ask your doctor or nurse what help and support are available to you and your friends and family.

There are things you can do, people who can help and ways to cope with a diagnosis of cancer.

Rare cancer organisations

Cancer 52

This is an alliance of 90 organisations working to address inequality in funding for rare cancers and improving outcomes for patients.

Email : info@cancer52.org.uk

The Rare Cancer Alliance

The Rare Cancer Alliance offer support and information to people affected by rare cancers. It has a forum where you might be able to meet others with the same cancer as you. 

The Rare Cancer Forum

The Rare Cancer Support Forum has several message boards so people with less common or rarer cancers can get in touch with each other. Friends and families of people with rarer cancers can also use the message boards to share their experiences, give support or get advice from people in similar situations.


RareCan allows people with rare cancer types to share their information with researchers. By doing this they hope to speed up the finding of new treatments and ways to diagnose people with rare cancer. RareCan also allows people to connect with other people who have a rare cancer.


EURACAN connects patients who have rare adult solid cancer to expert health care centres across Europe.

Finding information

It can be hard to find useful information about a rare type of cancer. Ask your doctor or specialist nurse if they know of any suitable information. You could ask about the best term to use if you want to look for information online.

Check if we have information on your cancer. Type the name in the search box at the top of each page. Or look for your cancer type on our A to Z list.

You can also contact the Cancer Research UK information nurses on 0808 800 4040 9am to 5pm Monday to Friday
  • First results of the EORTC-SPECTA/Arcagen study exploring the genomics of rare cancers in collaboration with the European reference network EURACAN
    M Morfouace and others
    ESMO Open,2020.  Volume 5, Issue 6, Page e001075

  • Burden and centralised treatment in Europe of rare tumours: results of RARECAREnet—a population-based study
    G Gatta and others
    The Lancet Oncology, 2017. Volume 18, Pages 1022 to 1039

  • Rare cancers: Challenges & issues
    R Pillai and K Jayasree
    Indian Journal of Medical Research, 2017. Volume 145, Issue 1, Pages 17 to 27

  • Rare Cancers Europe: joining forces to tackle a common problem
    R Schaefer
    Rare Tumors. 2012. Volume 4, Issue 2, Page e24

  • What is a Rare Cancer? 
    G Eslick
    Hematology/Oncology Clinics of North America, 2012. Volume 26, Issue 6, Page 1137 to 1141 

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
01 Dec 2022
Next review due: 
01 Feb 2025

Related links