Today is Rare Disease Day. The aim of the day is to raise awareness about rare diseases and their impact on people’s lives. In this blog, information development nurse Ali explains some key facts about rare cancers.

What is a rare cancer?

A rare cancer is a cancer that is diagnosed in fewer than 6 in 100,000 people a year.

Rare cancers are more common than you might think

About 1 in 5 cancers (22%) diagnosed in the UK each year are rare cancers. There 198 different types of rare cancer.

Some rare cancers are much rarer than others

Rare cancers include some cancers you may have heard of, such as thyroid cancer, which affects about 3,500 people in the UK each year.

But there are also lots of very rare cancers that most of us haven’t heard of. Some of these affect fewer than 10 people a year.

There are different reasons why a cancer might be rare:

  • Most cancers start in cells that cover organs inside the body or make up the skin. A rare cancer might start in a different type of cell, for example in a bone cell or a nerve cell.
  • A rare cancer might be a subtype of a more common cancer. For example, breast cancer is the most common cancer in women, but some subtypes of breast cancer (such as inflammatory breast cancer or breast cancer in men) are rare.
  • The cancer may be in an unusual part of the body for that type of cancer. For example, melanoma (a type of skin cancer) that starts in the in eye.
  • Rare cancers  may affect a child or teenager. All cancers in children and teenagers are considered rare cancers.

Having a rare cancer can bring extra challenges:

  • It can take longer for the cancer to be diagnosed.
  • Some people need to travel to a specialist centre for treatment.
  • It can be more difficult to meet other people with the same type of cancer.
  • Other people may not have heard of the cancer you have or understand what you are coping with.
  • Getting information about the cancer and its treatment can be difficult.

Where you can get help and support

Your cancer team are the best people to answer any specific questions you have about the cancer or your treatment. They can tell you if there are patient organisations for the type of cancer you have.

Patient organisations may know about new treatments and research trials that are being run. They may also have contact with the leading specialists for that cancer in the UK. Cancer52 is an alliance of over 80 patient organisations for less common cancers in the UK. 

Some patient organisations have online communities where you can read other people’s experiences, ask questions and share how you feel. Macmillan’s online community has groups for several rare cancers.


Check our website for information on many types of rare cancer. It also has general information on coping with cancer such as coping with side effects or symptoms, how to deal with work or money worries, and how to talk with family and friends about cancer.

If you can't find information on the type of cancer you have, the website Orphanet may be helpful. Remember that there might be other names used for the type of cancer you have. This can be helpful when you are searching for information.

To see what else Macmillan's cancer information team has been blogging about, please visit our blog home page! You can subscribe to receive our blogs by email or RSS too.

We're with you every step of the way
The Macmillan team is here to help. Our cancer support specialists can answer your questions, offer support, or simply listen if you need a chat. Call us free on 0808 808 00 00.
Comments? Feel free to add them below (you need to be logged in).
Keep in touch Follow Macmillan’s cancer information team on Twitter @mac_cancerinfo