England and Tottenham striker Bethany England said "cancer is riddled through" her family as she backed a charity event raising funds for new treatments.
The 29-year-old's aunt was diagnosed with leukaemia and died aged 42 when England was a child.
The Tottenham captain also lost her grandad to skin cancer and her great-grandmother died of throat cancer.
"We've got a lot of cancer on both sides of my family," said England.
Her two grandmothers are survivors of the disease, while another aunt also had breast cancer.
"My mum ended up giving my auntie a bone marrow transplant," added England, speaking at a Stand Up To Cancer fundraiser.
"That gave her a few more years of life but sadly, in the end, her body rejected what mum had given her. It was really sad to see my mum go through losing her sister after everything she'd done to try to help save her life."
England added: "Cancer is riddled through our family unfortunately."
Tottenham team-mate Kit Graham also revealed her sister Kelli had been diagnosed with a rare cancer at 24.
"I think I heard the word 'cancer' and just kind of shut down," Graham said. "But thankfully Kelli had surgery and radiotherapy and she is here with us still. So thankfully that is a good cancer outcome."
More than 375,000 people are diagnosed with cancer every year in the UK, according to Cancer Research UK.
The charity's Stand Up To Cancer campaign with Channel 4 aims to raise funds to accelerate research into new treatments.