Blackpool born Coleen Nolan has revealed that her sister Linda has been diagnosed with secondary cancer.
The singer and performer, 58, who found fame with The Nolans in the 1970s, had been cancer-free after being treated in 2006 for breast cancer.
But Coleen revealed on Loose Women that Linda had been diagnosed with secondary cancer, which is "not curable" but is "treatable", after falling up the stairs around three weeks ago.
"Linda wants to get it across she's not dying of cancer. She's living with cancer. They've said it is treatable, she could have years. We have to focus on that," Coleen said.
"She actually broke her hip. She went to hospital and while they did the scan of her hip, they found secondary cancer ... It was earth-shattering for us initially."
Coleen and Linda lost their sister Bernie to breast cancer in 2013.
Coleen had been on an extended break from Loose Women because the sisters wanted the news to remain private until now.
"She didn't want it to be out there at the time. We all had to get our head around it," she said.
Linda's husband Brian died in 2007 following a battle with skin cancer.
Coleen said the diagnosis came just as Linda had turned her life around.
"She'd had her great face lift, turned a corner from losing her husband," she said.
She added: "The positive thing is, although they've said it's not curable, it's treatable and it's not spread anywhere else.
"That's the positive attitude she wants me to get across, obviously it's going to be compared to Bernie".
Speaking of sister Bernie's death, Coleen said: "That was in Linda's mind when they first said it.
"But it was a completely different cancer and Bernie's had spread. Linda's hasn't. Like Bernie, Linda's so strong."
Fighting back tears, she said: "I went through such terrible anger, I was angry at the world, angry at cancer, angry for her. I just thought it's so unfair, she's just got it all together.
"It's taken her 10 years to finally get her life back and then it goes 'whack, here you go, now face this'."