With a movie candidly called "My Breast," you might expect a straightforward story. And you'd be right. What you might not expect is a story about breast cancer that has a lot of wit and very few tears, a rocky romance and a reasonably happy ending.

In retrospect, Joyce Wadler, a funny and hip and somewhat irreverent New Yorker, calls it "my little adventure."

The movie about her experiences airs Sunday at 9 on CBS, starring Meredith Baxter as Wadler, Jamey Sheridan as Nick DiStefano and James Sutorius as her pal Herb.

Wadler adapted the teleplay from her own book. As the story opens, Wadler, 43, a writer for People magazine, is involved in a relationship with DiStefano, a newspaperman she's known since they worked at the old New York Post. They've had some good times. They love '40s and '50s show tunes. They can repeat dialogue from favorite old black-and-white movies. They run away for romantic weekends and go dancing in the posh Rainbow Room. She feels comfortable with his big Italian family.

But he can't quite break off from a romance that lingers on, and he never mentions marriage.

Fortunately for Wadler, there is another pal from the Post, Herb, a humor writer and former boyfriend who appears to live part of his life on Wadler's sofa. Herb (Wadler changed his name for the story) proves to be the best of friends: He is there, through doctors' appointments, out-patient and surgery and hospitalization. He and another writer-friend, Eva (Sara Botsford), help Wadler gather information so that she knows what her options are.

Wadler has been praised for her zeal in informing herself about her cancer and the medical procedures proposed to deal with it. But she sees nothing unusual about that. "Any person can do this," she said. "You just have to have the attitude that you have the right to do this."

"My Breast" has two storylines: One is Wadler's discovery in 1991 that she has a lump the size of a robin's egg in her breast, despite having had a recent mammogram that indicated nothing awry. The other is her ongoing relationship with DiStefano.

In the film, Baxter, like Wadler a full-breasted woman, does not use a body double for the scenes involving breast examination. Actors play the doctors, but the close-up of a surgeon's hand examining Baxter's breast is that of a real physician.

"We all thought that was best," said Baxter, who is the movie's co-executive producer with Diana Kerew. "There's nothing sexual about this.

"When I read the script, I never visualized it any other way except with me and my breast. We decided this well ahead of time, when we started talking about the approach {to Wadler's story}. I didn't want to cut to some body double -- this was about the whole woman. Breasts have achieved this dubious stature of being this symbol of femininity, and it's very important this story is about the whole woman."

The movie was filmed in Toronto, where Betty Thomas ("Hill Street Blues") directed.

Wadler visited the set and noticed it included "an extraordinary kitchen for someone who doesn't cook."

She also had a look at the prop tumor, to see if it looked like the real one.

"The prop guys were talking about a guy who makes his living making body parts," she said. "They said to make the tumor, he'd gone to the medical books. I was very pleased with his work."

Wadler's tumor was a gray-looking mass, larger than she had expected. "It's called medullary cancer because it looks like medullary brain tissue," she said.

"{Actor} Dennis Potter, who played 'The Singing Detective,' he spoke of his cancer as a demon that was invading him and taking over. He named it Rupert. His was still inside his body, unseen and devouring him, but I had seen mine and there it was, lying like a lump. It was less frightening, afterward, when I knew what it was. I'm really glad I saw it."

Even though she had written the script, Wadler said the first time she saw the film was a bit unsettling. "I watched it first alone," she said, "and it made me nervous. I was surprised that I was crying. I didn't think that I was upset."

Any encounter with cancer has psychological effects beyond the tumor itself. People deal with that in different ways; often, writers write as a form of therapy for themselves and to inform readers through their own first-hand experiences. Wadler's account appeared first as a two-part article in New York Magazine, then as a book published in 1992 and recently reissued in paperback.

Wadler said when she decided to write, she had some decisions to make.

"There was the ethical thing," she said. "I don't do undercover stuff, but this was about my personal life, so I first had to go to everybody involved and say, 'How do you feel about this?' People were basically good about it. My first doctor was not crazy about it, so I changed his name. When I went to Nick and said, 'I want to write about this,' he said, 'Whether I'm an angel or {not}, I'll never tell you what to do.'"

Confronting one's mortality sometimes has a way of clarifying one's life. Wadler had begun to realize that friends who advised her to part from Nick may have been right.

"When I picked up the literature about breast cancer, I'd see a picture of a woman who'd had a mastectomy and there was a man who was gazing at her lovingly. And I had a guy who never gazed at me like that, not any time," she said.

Her nagging worry -- "Did I want everybody in New York to know I was involved in a neurotic relationship?" -- gave way to the pragmatic: She would tell the story.

She wrote while undergoing chemotherapy.

"The book came out a few months later, in the fall. We had an amazing response. We got hundreds of letters. They said they liked it because it was funny, it had a happy ending."

Susan M. Love, a physician who specializes in breast cancer and author of "The Breast Book," served as technical adviser to the movie. She also wrote the afterword to Wadler's book, saying, "The hardest time psychologically is after the treatments are completed."

But Wadler disagreed. "Wrong," she said. "Not for me. Of course, for the first few months, if I got a twinge in my breast, I was right there. But you do realize that time is finite. I somehow had in my head that everybody had 70 years. My father died of cancer at 67. So this is astonishing that something happened to me at 43."

"There is a positive effect in a strange way," said Baxter. "Any major trauma in your life that will bring you to your senses can be beneficial."

Wadler's love affair with DiStefano ended about the time her oncologist called to say she was going to have to have chemotherapy.

"Nick called up and said, 'Let's be a couple.' I didn't immediately say no. I think I had hoped that he would say that when I was faced with the possibility that I was dying. But that doesn't make people love you or people would be lining up to get it. This was a problematic relationship."

On the other hand, she and Herb are still the best of friends.

"Herb's mother had a run-in with breast cancer last summer. She wanted him to be the intermediary and make all the decisions. He said he should write a book called 'My Mother's Breast.' "

Wadler said she sees herself now as "living a normal life. I don't want to be like the poster girl. I don't define myself as a breast cancer survivor. Life goes on perfectly normally. There have been no lasting effects. I was really lucky: I had access professionally, good connections, medical care and time to make decisions."

Last year, Wadler received the Award of Hope from the Canadian Breast Cancer Association for the book. The piece she wrote on the subject for New York Magazine was a finalist in two categories of the 1993 National Magazine Awards. She was awarded the Guttman Breast Diagnostic Center's Breast Cancer Awareness Award, the Newswomen's Club of New York Award for Best Magazine Feature, and the Deadline Club's Award for Magazine Feature Writing.

Near the end of the book and the movie is Wadler's remark: "If the tulips are particularly yellow, I buy them."

On the day in late April when she called to talk about her movie, she had just bought herself an armful of lilacs.