Types of breast cancer and related breast conditions

Rare types of breast cancer

Doctors have developed ways of grouping breast cancers into different types. They sometimes call rarer breast cancers special type, and the more common breast cancers no special type.

Types of breast cancer

Most invasive breast cancers have no special features and are classed as No Special Type (NST) or not otherwise specified (NOS). Between 70 and 80 out of 100 breast cancers (between 70 and 80%) are this type. 

Rarer breast cancers are called special type breast cancers as they have cells with particular features. These are seen when the doctor looks at the cells under the microscope.

Some breast cancers might have some areas that are special type and some that are no special type. This is called a mixed invasive cancer.

Coping with a rare type of breast cancer

Coping with a diagnosis of cancer can be difficult, both practically and emotionally. It can be especially difficult if you have a rare cancer. Being well informed about your cancer and its treatment can make it easier to make decisions and cope with what happens.

Talking to other people who have the same thing can help. But it can be hard to find people who have had a rare type of cancer.

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

Find out about how to cope with cancer

Cancer Chat is Cancer Research UK’s discussion forum. It is a place for anyone affected by cancer. You can share experiences, stories and information with other people who know what you are going through.

Look at Cancer Chat

Support and information

There are rare cancer organisations that provide support and information, these include:

EURACAN

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

Visit the EURACAN website

Cancer52

This is an alliance of over 100 organisations working to address inequality in funding for rare cancers and improving outcomes for patients.

Email : info@cancer52.org.uk

Visit the Cancer52 website

Finding information on rare breast cancers

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.

You can also contact our Cancer Research UK information nurses. They can give advice about who can help you and what kind of support is available. Freephone: 0808 800 4040 - Monday to Friday, 9am to 5pm.

Research and clinical trials

There may be fewer clinical trials for rare types of cancer than for more common types. It is hard to organise and run trials for rare cancers. Getting enough patients is critical to the success of a trial. The results won't be powerful enough to prove that one type of treatment is better than another if the trial is too small.

Find out more about research and trials

Last reviewed: 22 May 2026

Next review due: 22 May 2029

The Dangoor Education logo.

Dangoor Education

About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education

Patient Information Forum. Trusted Information Creator.
Plain English Campaign award.

Help and Support

An icon of a hand shake.

Find a Clinical Trial

Search our clinical trials database for all cancer trials and studies recruiting in the UK.

An icon of two speech bubbles, indicating a conversation.

Cancer Chat forum

Connect with other people affected by cancer and share your experiences.

An icon of a landline phone.

Nurse helpline

Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.