Media playback is unsupported on your device Media caption Kris Hallenga told BBC Breakfast about her charity CoppaFeel!

Diagnosed with terminal breast cancer in her early 20s, Kris Hallenga is determined the disease is not seen as something that affects only older women. Through her charity, CoppaFeel!, she is fighting to raise awareness of breast cancer in young people.

"I don't think I'll ever forget the minor details of that day," says Kris Hallenga.

"The weather was beautiful. I can remember exactly what I wore - this miniskirt with tights. My mum said it was way too short, but I wore it anyway.

"The doctor just walked into this tiny little room and in a roundabout way just spat out the fact that I had breast cancer," says Hallenga.

A week after the diagnosis, scans revealed the cancer had spread to her spine.

That was five years ago, when Hallenga was 23.

Find out more Kris: Dying to Live will be broadcast on Wednesday 26 March at 21:00 GMT on BBC Three Or catch up later on BBC iPlayer

"I had stage four cancer, there is no stage five. I know the drugs can stop working at any time, so until then I've got a lot of living to do."

Cancer staging is used by doctors to describe the size of the tumour and the extent to which the disease has spread.

At stage one, the cancer tends to be smaller and contained within the area it started in. By stage four the cancer can be any size and has spread to another area of the body.

Hallenga discovered she had metastatic, or advanced breast cancer, in 2009 after a late diagnosis.

"That was end of innocence really," says her mother, Jane.

"All of a sudden you have to realise and start fighting against what's been handed to you, this fate."

Hallenga says she will never know whether she would now be free of breast cancer if she had been diagnosed earlier.

Image caption Kris Hallenga has received radiotherapy for a brain tumour

The cancer has since spread to her pelvis, liver and hips and she also has a tumour in her brain. She has hospital visits every month, body scans every three months and takes a range of medication to help slow the spread of the disease.

"When I was diagnosed I read that my life expectancy was just two and a half years. Thanks to treatment, I'm still here five years later, but so is my cancer," says Hallenga.

She is determined that other young people should be trained to spot the early warning signs of the disease and check their breasts regularly.

Breast cancer: What to look out for Any sign of a lump or thickening in the breast

A swelling or lump in the armpit or near the collar bone

Discharge from the nipple

Change in the shape or size of the breast

A change in the shape of the nipple, for instance becoming inverted

A rash on the nipple or nearby area

Changes to the skin on the breast such as dimpling

Incessant pain in the breast or armpit Sources: CoppaFeel! and Cancer Research UK

A month after her diagnosis, Hallenga set up a charity called CoppaFeel! with her twin sister, Maren, to help raise awareness at schools and music festivals about the importance of early diagnosis.

The chance of developing breast cancer before the age of 30 is around 0.05% or one in 2,000, which increases to one in 50 or 2% before the age of 50.

One in three women diagnosed with breast cancer in England is aged over 70.

Although the risk of getting the disease does increase with age, some studies suggest the types of breast cancer diagnosed in younger women can be more aggressive. Therefore, survival rates can be lower for younger women with breast cancer than for those in their 50s or 60s.

In 2005-09, 90% of women in England aged 50-69 were alive five years after diagnosis, compared with 84% of females aged 15-39.

The earlier the diagnosis, the less chance the cancer will have spread to another part of the body. Approximately 10% of women with stage four, or advanced tumours, live for more than 10 years, compared with 85% of women with stage one breast cancers.

Young women who have been diagnosed late after an emergency referral often contact Hallenga for advice and support. She has come to see herself as a voice for those who are going through the same thing.

Image caption Kris Hallenga (left) works with her twin sister Maren to alert young people to the risks of breast cancer

Her family, however, wish she would just sometimes take a break.

"She's like this superwoman who is taking on the world, trying to save lives, trying to beat this cancer," says her sister, Maren.

"I think sometimes she just needs to have a good cry about it or just get [angry] about it."

According to Kris Hallenga there is no real respite when living with advanced cancer.

"You can never predict what's going to happen from one day to the next, and you can never say, 'Oh I'm fine, I'm in remission,' none of that exists.

"This is incurable and it's going to happen at some stage. I just wish it happens a few million years in the future, or never," says Hallenga.

However, she is making the most of everything in her life and says that every day she enjoys and is grateful for is "another level of acceptance".

"Cancer has given me a life and given meaning to what I do with my life.

"I'd really hope and like to think that I would have that same appreciation of life even if I didn't have cancer, but this has just made it all the more important."

As she stresses on her Twitter feed, she does not want to be described by anyone as "fighting," "suffering" or "battling". She would rather be known as "simply living".

Kris: Dying to Live will be broadcast on Wednesday, 26 March, at 21:00 GMT on BBC Three. Or catch up later on BBC iPlayer