Former Emmerdale star Lisa Riley has taken her share of flak over the years but dancing's transformed her life - and helped her cope with the death of her mother. She tells Hannah Stephenson why she won't let the shadow of cancer hold her back.

Wearing a black sweatshirt emblazoned with the glittering word 'POW', Lisa Riley greets me with that huge, ray-of-sunshine smile.

Her personality is as sparkling as the sequins on her frocks on Strictly Come Dancing, the show that's been her lifeline since the death of her mother last year.

There's little doubt that Strictly has changed her life. Since she reached the semi-finals in 2012, Riley's appeared on the Strictly tour, backstage spin-off show Strictly Confidential, is co-presenting the BBC Two strand It Takes Two and will be hosting the upcoming arena tour as well.

She's also visited schools and dance academies to give motivational talks, and is keen to see dance introduced into the national curriculum.

"My confidence with Strictly rose to gas mark 10," she says. "There had been times when my confidence had been knocked, career-wise. For the first time, the press could not turn round and say, 'You are unhealthy'. I ran up them stairs quicker than Robin [Windsor, her dance partner] and he's been dancing since he was five. They couldn't say, 'You're fat and unfit', because I'm so fit.

"Because of Strictly, I was allowed to have this voice, and for the first time in my life I could wear what the hell I liked and I could be sexy."

Today, she's still buxom and bouncy, but there's noticeably less of her. She says she never consciously tried to lose weight but the pounds melted away because of the sheer volume of training. She's gone from a size 28 to an 18 in little more than a year and would like to stay there, simply because she feels so fit, not because she worries about her weight.

"I didn't feel better [losing weight] because I'm still me, but I became very aware of my ability in dance."

She's now promoting her autobiography, Never Judge A Book By Its Cover, which charts her life from her childhood in Bury and her progression through Oldham Theatre Workshop, which she joined aged nine, to becoming comical tart-with-a-heart Mandy Dingle in Emmerdale, subsequent roles in Fat Friends, a stage production of Calendar Girls and presenting You've Been Framed, right through to her success on Strictly.

Yet, behind all the smiles, there's been the intense sadness of losing her mother Cath to breast cancer in July 2012, two weeks before she joined the hit TV dance contest.

During those last heart-rending months, her mother went from feisty to frail, becoming a shadow of her former self and Riley nursed her at her own home. She says she now associates being thin with death.

"Me and mum were carbon copies of each other. She was the life and soul and would never have wanted me to sit and throw my head in a pillow and cry, but I was dying inside.

"It was devastating. My whole life just felt like it was over, yet on the other side of the coin my mum knew that I'd got Strictly and said, 'Darling, just be you', and that's what I did during the series. I went for it."

Riley, 37, still has what she calls 'baseball bat' moments, when something triggers the grief - like spotting a lady in a yellow jacket in a cafe recently (her mother loved yellow) and feeling as though she'd "just crack".

There are times when she gets lonely, but she tries to surround herself with friends, making the most of Facetime.

"That's probably why I keep myself so busy. The worst times are the mornings in my house in Manchester, when I'm at home pottering around. I can find myself at my kitchen table and I'll just cry."

Many of her relatives have died from cancer and she's the first to admit she has a worrying gene pool, but she won't let the shadow of the disease stand in her way.

"No, I haven't had any genetic testing to see if I'm more susceptible," she declares. "I live every day for today, not longevity, and also I could get knocked over by a bus tomorrow so what's the point worrying about it all too much? And me, Mum and Poppa [her grandfather, who also died of cancer] always laughed at what a terrible gene pool they'd given me."

Up to now, boyfriends have not been her strong point. In the book, she reveals that her partners have included a fraudster who ended up in jail and a married man who dumped her and returned to his wife. For a while she became the talk of the tabloids, and her confidence hit rock bottom.

"My behaviour was severely denting my career, because I couldn't cope. I didn't want to face being pointed at. I never wanted to be the scandal."

Looking back, she admits she'd gone off the rails after joining Emmerdale in 1995 aged 19 - because she simply couldn't handle the fame, and life became one enormous round of drinking and partying.

"At the worst point, I was having five bottles of wine a night and shots. I was verging on alcoholic. I had no 'off button'. I'd be sick and then I'd carry on.

"When you're in a soap," she adds, "people think you are that person, no matter where you go or what you do."

She says her father brought things to a head when he told her sternly that she was a mess and needed to clean up her life. His words prompted her to cut down on excesses.

Today, she says she's more guarded as far as men are concerned, and is tight-lipped about any current relationship.

"I never regret anything. If you make a mistake, it's a learning curve and it's there for a reason. I live my life by that. These things make me stronger."

When she's out and about these days, the public call out 'Foxtrot!', not 'Mandy Dingle!'

She has no intention of returning to Emmerdale. "I've worn that hat," she says. "She was hugely successful. I was so lucky that the writers wrote for me. But there's a lot more out there than soap operas.

"It was my choice to leave. I had six-and-a-half phenomenal years and made friends for life, but as an actor, we put different hats on. We don't play the same part.

"I know you've got people in soaps who've been there for 30-odd years, but to me that's not acting. You might as well work at the HSBC bank."

In the New Year, she'll be hosting this year's Strictly arena tour from early January and is appearing alongside Martin Shaw in a new series of BBC detective drama George Gently.

"As a female actress, you dread the gap between 40 and 47, because there's not many roles and if there are, you play a boring mum - and those roles aren't that much fun.

"But I'm approaching my forties beyond excited, because it's not looking remotely boring."

With that, she gives me that enormous smile again before dashing off to her next interview. I'm sure her mother would be proud.

:: Never Judge A Book By Its Cover: The Autobiography by Lisa Riley is published by Orion, priced £18.99. Available now