While the crew on the forthcoming Sex and the City: The Movie has spent the past 18 months desperately trying to keep the plot under wraps, one cast member has been struggling with a far weightier secret: Cynthia Nixon, who plays lawyer Miranda Hobbes, has been battling against breast cancer. Speaking on a recent American chat show, the 42-year-old actress revealed that during a routine mammogram in 2006 a tumour was diagnosed. She went on to say that she didn’t want her scare to become public knowledge while she had surgery to remove the lump.

It was while starring in the off-Broadway production of The Prime of Miss Jean Brodie that she received the diagnosis. “I felt scared,” she has said, “but I was very cognisant of the fact that if it’s going to happen, this is the best way for it to happen – it’s found so early and we can just get right on it.”

Her partner, Christine Marinoni, was a vital source of support. The couple went public in 2004, when they revealed a year-long relationship that stretched back to Nixon’s split from the musician Danny Mozes, the father of her two children (Samantha, 11, and Charles, 5). According to reports, Nixon and Marinoni hope to get married this autumn.

“I have to say that in terms of the particular person I’m with I guess I do feel that the ideal man is a woman,” laughs Nixon. “I feel like she’s much more intuitive about what’s going on with me. She’s much more willing to treat it like a partnership. We eat together, shop and cook together, raise children together. And there’s much more sense of the task at hand and we both fit in. I’m in love with her because she’s her; it’s hard to know if I’d be in love with her if she were a man. If she were a man, would she be differ-ent? Would she still be this intuitive? Would she still be this devoted?

“Certainly the kids were fine with our relationship. This is New York City – a very multicultural world where gay people are not so shocking!”

Nixon was herself born in New York and her first acting role came at the age of 12, when she starred in a 1979 Afterschool Special for ABC. Her parents divorced before she hit her teens, and when she was 13, and had just completed her first big movie, Little Darlings, her mother found out she had breast cancer. “I remember there were a number of hushed conversations between my mother and her boyfriend,” she says. “I know she told me, but I can’t remember the actual moment. It was very matter-of-fact. My mom is just very streamlined – she doesn’t believe it’s good to make a fuss.”

The young actress appeared simultaneously in two Broadway plays directed by Mike Nichols, Tom Stoppard’s The Real Thing, and David Rabe’s Hurlyburly, and also starred in the Best Picture winner Amadeus, playing Mozart’s tearful maid. She still lives in New York, on the Upper West Side, and says that she feels it is easier for an actress to age on the East Coast rather than in Hollywood. “It’s much easier to be in New York because there’s a higher level of reality as to what people should look like,” she says.

However, Nixon concedes that the tabloid frenzy that accompanied her confession to a lesbian relationship was rather startling. “Certainly the attention was a wild, crazy thing. It was like a fire; it flared for a bit and then died down to a slow burn. And the nice thing about it was that really there wasn’t much to say, once we’d said it. People had a week or two talking about it.” She laughs. “And sometimes they had a hard time separating me from Miranda in Sex and the City. Honestly, people wrote to papers saying things like ‘I don’t understand; Miranda kissed a girl and didn’t like it!’

Also, part of the initial hysteria was that because the four characters are seen as saying something about modern American womanhood, somehow my decision was also saying something about modern American womanhood. Really I was just saying something about me, but people are so used to thinking of us as archetypes.”

Indeed, Michael Patrick King, the show’s producer and the writer-director of the long-awaited movie, believes that the four Sex and the Citycharacters all represent different aspects of a woman’s personality, allowing viewers to connect with different characters depending on their mood. “They are all facets of one person,” he says. “There’s a side who’s very demonstrative and confident, like Samantha, and then there’s the dreamy Charlotte side, and then the Miranda character, who’s cerebral and pragmatic. So they all reflect something that women often wish they were.”

“The storylines were strong, and with the girls, I think people liked that you see their strengths but you also see their weaknesses,” says Nixon. “Also, in Candace Bushnell’s book, dating can be very bleak and hard. In a humorous and, sometimes, a sad way we did show that, but there was always this safety net, which wasn’t in the book. Here, whatever happens we’re all there for each other.”

This group bonding is called into play in the new movie. It picks up four years after the show left off and, while the girls have all built separate lives, they are reunited for Carrie’s wedding to long-time lover Mr Big (Chris Noth). Then she suffers heartbreak – the details have not been released, but it seems that a major character dies.

“Basically, we’re all older when the film starts,” explains Nixon. “Two of us are married [Miranda and Charlotte], the way that we were at the end of the show, and now Charlotte has a daughter. Carrie’s with Big, and Sam is with her guy in LA, and even though we all come together, there’s a thing that happens when you get older: we all become more wrapped up in our men, our children and our lives. We’re like four queens in our queendoms and then we come together to support someone.”

In truth, the film almost didn’t happen at all. It was originally planned for 2004, when the series ended, but Kim Cattrall, who plays Samantha, refused to come on board. She had issues in her personal life – her father developed dementia, and Cattrall spent more time at home in Canada – and wanted something approaching fiscal parity with star performer Sarah Jessica Parker.

The financial wrangling has now been resolved and Nixon is happy with the outcome. “Honestly, I would say whatever relief I felt when the show finished was minimal,” she smiles. “For many years we only filmed for three or four months a year, so it was a dream job. I knew it was coming to an end and had made my peace with that, but I certainly did miss it.”

Nixon has just started shooting the film Lymelife, alongside Alec Baldwin and Holly Hunter, and will return to the stage next season in New York with a production of Distracted.

Is the film the final final curtain for Sex and the City? “I don’t know,” says Nixon. “We’ve not talked about anything else.” The unspoken issue is, can the four characters make the leap from small to big screen and retain the charm that kept audiences hooked. Has their time passed? Or is there life yet in the bright, shiny Manolos?

Sex and the City is released nationwide on May 28 2008

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