Peter Andre and his family cannot bear to talk about his brother's death nearly six years ago because it is "still so raw".
The 45-year-old singer lost his sibling Andrew to kidney cancer in 2012 aged 54 after a 10-month battle with the disease, and the family are still "so devastated" about his passing, which "tore [them] apart".
Speaking at a Jog On To Cancer event in London's Café de Paris, he said: "It came out of the blue. He was healthy, he was active. But not only did he get this terrible disease but he lost his life shortly afterwards. And it tore us apart.
"Early detection is key. Do I think my brother's life would have been saved it was detected earlier? Sure.
"The bigger picture here is that millions of people are going through this right now.
"As a family, we're still so devastated by this loss we can't sit down as a family and talk about it because it's still so raw."
Peter - who has daughter Amelia, four, and 16-month-old son Theo with wife Emily MacDonagh - is a "very proud" ambassador of Cancer Research UK, but when the charity first approached him about a role following the death of his brother he turned them down because he was "angry" at the disease.
According to The Sun Online, he said in the speech: "I remember when we first lost Andrew and Cancer Research got in touch to see if I wanted to get involved.
"I told them, no. I was angry at cancer. I said I wouldn't support something that took my brother's life."
Peter - who also has son Junior, 12, and 10-year-old daughter Princess from his marriage to Katie Price - previously revealed his brothers, Chris, Danny and Michael, couldn't bear to read the chapter in his book 'Between Us' which discusses how he felt during Andrew's cancer battle and following his death.
He explained: "I was nearly two weeks late delivering [the book] because that was the only chapter I couldn't do. My brothers won't read it. They said, 'Bro I hope you don't mind, but we don't really want to read it.' "