Kris Hallenga, the founder of the charity CoppaFeel!, which raises awareness of the importance of young women checking their breasts for early signs of cancer, has died aged 38 after being diagnosed with the disease 15 years ago.

The campaigner, from Cornwall, was 23 when she was given the news she had stage 4 cancer that had spread to her spine.

She started the charity CoppaFeel! in a field at a festival. It became one of the leading cancer awareness charities, encouraging millions of young women to check their breasts and creating checking tools. Its message was projected on to the Houses of Parliament and also included the showing of the first nipple on an advertising billboard.

In an interview with the Guardian in 2021, Hallenga said she had been motivated by being “confused and baffled” when diagnosed.

“I kept thinking: ‘This is bullshit. Why didn’t anyone tell me to check my boobs? Why didn’t I know I could get breast cancer at 23? I’m pretty sure my friends don’t know either, and, if none of us do, then literally no young person in this country fucking knows this secret. This needs to change.’ And I got this wave of energy,” she said.

Together with her twin sister, Maren, Hallenga saw the charity grow to become the third most recognised cancer charity in the UK, and one that was “actually saving lives, which blows my mind all the time”, she said in the interview.

Hallenga won a Pride of Britain award for her campaigning, after being nominated by Cancer Research UK. In 2017, she stepped aside as chief executive of CoppaFeel! to move to Cornwall and spend more time with her sister and write a memoir, Glittering a Turd.

In a statement, CoppaFeel! said: “We share the sad news that our founder, boob chief, colleague, friend and queen of glittering turds, Kris, has died. Kris was the biggest promoter of being ‘alive to do those things’. She approached life in a wildly creative, fun and fearless way, and showed us that it is possible to live life to the full with cancer.

“In 2009 Kris was diagnosed with secondary breast cancer at the age of 23, after being turned away from her GP for over a year. By the time she was diagnosed, it was terminal. Kris’ ambition was for no one else to find themselves in her position and so CoppaFeel! was born, to ensure breast cancers are diagnosed early and accurately.

“Kris has reached millions of people with her message of health advocacy and empowerment, successfully campaigned for cancer education to be included in the school curriculum, won the women of the year outstanding young campaigner award, received an honorary doctorate in public administration from Nottingham Trent University and wrote a Times bestselling book: Glittering a Turd.

“Kris’ life mission was that CoppaFeel! would no longer need to exist, with late diagnosis of breast cancer eradicated in her lifetime. We are committed to continuing Kris’ legacy, to ensure that everyone has the best chance of living a happy and healthy life. If you’d like to support this mission, you can donate here.

“For 15 years Kris had been living with secondary breast cancer. She hasn’t lost a battle, she wasn’t in a fight and she certainly wouldn’t want you to see her death as tragic. She was simply living. She was 38 and died with fulfilment and a heart full of love.

“Please remember the amazing life Kris led and the things she achieved, but above all else honour her memory by checking your chest … it could just save your life.”

• Breast cancer
• Health
• Cancer
• Charities
• Voluntary sector
• news