Sheridan Smith
Actress Sheridan Smith was eight when she lost her older brother Julian to cancerANDREW COWIE/AFP/GettyImages

The C Word actress Sheridan Smith has opened up about losing her brother to cancer 25 years ago, admitting that his untimely passing has made her "value life".

The one-off BBC drama will see the 33-year-old portray her close friend Lisa Lynch, who died from cancer in 2013.

The West End star says the challenging role brought back difficult memories of losing her brother Julian to the disease in 1990 when she was eight-years-old and her sibling was 18.

The BAFTA-winning actress told the Radio Times: "Of course I've been affected by my brother's death... It makes me value life, cherish my loved ones and be grateful for every day I have with them.

"But it's not something I'd want to dwell on now. Because this project isn't about me.It's all about Lisa, and I wouldn't like to lose that focus. It's true, though, that losing someone to cancer really resets your perspective."

Lynch was diagnosed with breast cancer at the age of 28 and heroically documented her battle in a blog, which was eventually turned into a book.

The blogger died in 2013 aged 33 after the cancer spread but before losing her life, personally contacted Smith via Twitter to state that she only wants the actress to play her in the series.

Smith admitted to the publication: "I was always going to do it. And the least I could do was show Lisa's experience as truthfully as possible. Lisa's blog was her way of dealing with it, so that when she was around her family they didn't have to constantly talk about 'it' but at the same time, it raises awareness of breast cancer in a really positive way.

"I'm hoping the film will raise an even wider awareness, because if people haven't been affected by cancer, they might not pick the book up, but if it's on television there's a chance they'll tune in and get the message."

Smith is currently filming the TV film and says that she has been inspired by Lynch's "courage and bravery".

The actress explained: "I couldn't help but love her. That's why I want to tell her story. For Pete, for her family and for everyone whose lives are touched by cancer. I'm so sad that Lisa won't see the finished drama, having been so involved in the development of it. Lisa's story is the most important thing at the moment. I'm honoured she wanted me to play her on screen."