Tanya ended an affair with Max back in the summer after she suffered a health scare. Since then, she has been battling cervical cancer with only her daughter Lauren (Jacqueline Jossa) aware of what she is going through.
However, Max (Jake Wood) returns to Albert Square later this week and is keen to support Tanya when he hears about her condition.
Joyner told TV Times of the storyline: "Tanya and Max's relationship has always been based on her having to be sexy and attractive, to keep him on his toes. Now she's in a situation where she hasn't got the energy or the ability to be like that, so the terms of their reunion are utterly different.
"Them being back together is like Marmite. Some people hate the idea, others love it."
The actress said that she is keen to stress the importance of early detection after researching Tanya's illness.
Joyner said: "The thing about cervical cancer is that the earlier it's diagnosed, the easier it is to treat. No woman enjoys having a smear test but undergoing cancer treatment is a lot worse. The NHS provides women with regular smears and that's something we should all make the most of."
EastEnders' big week for the Brannings continues tonight at 7.30pm on BBC One.
> EastEnders' Max to return in huge Branning week
> EastEnders Max return is lovely, says Jo Joyner
> EastEnders actor Jake Wood chats to Digital Spy
> Read more EastEnders spoilers and news
Watch the EastEnders 'Branning Week' trailer below: