The actress's character Tanya Jessop will be diagnosed with the illness later this month. Tanya's new plot begins next week when she learns that she has abnormal smear test results.
EastEnders bosses officially announced the storyline in June, confirming that the show had worked closely with various experts and charities including Macmillan Cancer Support for research purposes.
Meanwhile, speaking to All About Soap about how she has personally researched the plot, Joyner commented: "I've talked to a lot of survivors of cervical cancer through a charity called Jo's Trust - the name's just a coincidence! They also have a great website, which is very informative and has helped me a lot.
"It's a privilege to be given any sort of serious storyline and a real responsibility. I'm going to make it as honest and true to life as I possibly can."
Tanya receives the worrying news about her smear test results just as she is preparing to tell husband Greg (Stefan Booth) that she wants to be with her ex Max Branning (Jake Wood).
Asked whether it makes Tanya question who she wants to be with all over again, Joyner replied: "Definitely. She remembers her mum looking at her dad with pity [when he was ill] and she'd hate that happening to her. She has some serious thinking to do about her future now."
> Read our full spoilers for next week's EastEnders episodes
Watch some of Tanya's EastEnders best bits in the video below: