A DEVOTED sister who lost her "best friend" to cancer has taken on an ambitious challenge - to raise £1million in her memory.

Roseann Gallagher's long ­battle with the disease came to an end in February, last year.

The Glasgow mum-of-one was first diagnosed in November 1999 and was given a 48% chance of survival over the next five years but fought on for 12.

In August 2011, Roseann, from Sandyhills in the east of the city, was given the news she had been dreading, the cancer had returned and this time was in her lungs, bones and latterly, her liver.

She passed away at home in February last year, at the age of 51, with her sister, Debbie Dean, and her son Billy Linton by her side.

And now Debbie, 43, has taken up the challenge first started by Roseann - to raise £1m for other cancer sufferers. Debbie, who lives in Springboig, has already collected more than £2150 and is now preparing to cycle 380km through Yosemite ­National Park in California.

Following her initial diagnosis, Roseann, who was a project manager with Bield Housing, wanted to be as prepared as ­possible for what lay ahead.

She tried to find personal ­accounts written by people who had lived through the disease but was unable to do so.

So, she decided to write a book about her experiences, called Cancer No Not Me!

Debbie, a care worker, said: "Roseann wanted to use the book to help people going through cancer treatment, like she was, but also to raise money.

"She was a very determined person and once she put her mind to something she was incredibly focused on it."

But her efforts were put on hold when her husband John Gallagher suffered a massive heart attack while out walking the couple's dogs in Mount ­Vernon Park, in January 2009, and died. He was just 46.

Roseann, who was in ­remission at the time, was devastated.

Debbie added: "It came as a massive shock. John had been feeling unwell but nothing could have prepared the family for this."

Roseann published her book in 2010 and set herself the ambitious fundraising target, vowing that proceeds from every sale would go to cancer charities - including Breast Cancer Care.

But tragedy sadly hit again when Roseann returned from a holiday in Palma Nova, Majorca, in August 2011, feeling unwell.

Debbie said: "Roseann went to the doctors and was ­referred to hospital.

"Doctors said they thought the cancer had returned and carried out more tests before telling her it was in her lungs and bones. It then spread to her liver."

Debbie added: "Roseann had been through so much but she stayed brave.

"She would say to doctors 'just be honest and tell me how bad it is so that I know what I have to fight'.

"She was so strong. She said to me 'I am not scared to die, I am just not ready'."

When it was revealed that ­Roseann's cancer was terminal, Debbie stepped in to provide her sister's palliative care.

Debbie added: "In the end she was given two to three months but died three weeks later in February, last year.

"I moved in to care for her. It was hard but I know she would have done it for me. We were not just sisters, we were best friends. She is the bravest person I know."

And Roseann will be the inspiration when Debbie takes on her ambitions challenge to cycle 380 km around Yosmite National Park, over mountainous terrain.

She sets off for the trip on ­October 5 and will complete the cycle alongside Roseann's son Billy, 37, and her sister Janet MacGregor, 50. She said: "I am a bit apprehensive but I know ­Roseann will be in my mind pushing me along. She would have been right up for it - she would try anything."

Debbie has already taken part in the Great Scottish Run half marathon and has organised a Zumbathon which takes place on April 27 at Penilee Community Centre from 11.30am.

She added: "I want to finish what Roseann started and ­continue with her pledge.

"I don't know how long it will take me but I'm going to give it a really good try for my sister, my best friend Roseann."