Marvella Bayh looked at the blurb that had been sent out to plug a Good Housekeeping article. "Marvella Bayh is dying," was the opening sentences.

Bayh shakes her head. Her soft, almost babyish voice becomes emphatic, and she speaks in italics. "I have never, ever said I was dying of cancer. I am living with the knowledge that I have cancer.And my life is rather normal.

"There are thousands and thousands and thousands of people out there living reasonably normal lives with the knowledge that they have cancer - and that right now there is nothing that will cure it. But there are now many advances, many ways to keep it under control."

The wife of the Indiana senator stops and thinks of the headlines, the nightly news programs that flashed the words - Marvella Bayh is Dying. "Someone reaching for a headline picked a quote from the doctor and cut it in two so it was not even complete, and lifted that up and put it on the cover of the magazines as if it were quote from me." Next to her picture on the cover, the incomplete sentence says "Just one good year to live . . ." (The rest of the quote inside the magazine says "perhaps five or six years or more with treatment.") Wives of politicians have never been able to keep their illness private. From Joan Kennedy to Betty Ford, from Happy Rockfeller to Margaret Trudeau, the illness have been mirrored publicly.

Bayh, slightly exasperated sighs. "After all, everyone who has been born is dying. . . . I want all the other women out there who are walking this same road to know I have not given up hope and that my life is full and happy and that I don't feel I have just X amount of time to live." The doctors told Bayh February that her cancer was "widespread and inoperable."

She has since swithced from doctors who are not "upbeat" enough. "I think the person's attitude and their own hope and not giving up is so vitally important. I cannot tell you the number of letters I have had from people saying why doctor told me - or my brother or sister or what have you - 15 years ago that they had less than a month to live and now they're sailing or golfing or whatever.

"I believe in the great power of hope and positive thinking and I believe especially in the power of God. And of cause I'm praying for a miracle."

Marvella Bayh looks terrific. She is slim, with a soft fluff of blond hair and an unlimited face - a woman of 45 looking several years younger.Her look always has been deceptively soft. It masks the quick, ambitious mind of a perfectionist with formidable determination. For years she was often regarded in Washington as brighter than her husband: the driving ambitious force behind him, who really wanted to be president herself. She used to say, "Birch is my career."

She has, however, changed greatly, in the seven years since she first learned she had cancer. In 1971, her right breast was removed. Following her mastectomy her husband faced the TV lights and newspaper reporters and in a choked voice moved out of the race for the presidency. In 1976, when Birch Bayh tried again, Marvella, the relentless team player of the past, was no longer at his side.

It has been a startling metamorphosis for the woman who moved out of Enid, Okla. determined to rise as far as she could in politics in the days when the only acceptable political role for women was as a helpmate.

"Politics does not play a part in my life," she says today. The woman who used to be impatient and demanding of the senatorial staff kept to a rigorous schedule of campaign speeches, and dreamed of being first lady now says, "Oh, I sometimes think we wives may have thought we made more difference than we did.

"Politics remains demanding in our family life - but I have learned to do what I want to do." Her husband, campaigning for collegues, calls from Indiana. She says, "I do need to talk to you but I can't now. Well, thank you for calling . . ."

She is quickly back talking about the things that fulfill her now, primarily her campaign as a spokeswoman for the American Cancer Society. She halted her activities last week following a virus attack that left some fluid in her lungs. "It's the same virus half of Washington's had," she says, dismissing it as minor. "I have speeches lined up for spring . I don't want people to think I'm planning on dying in the next few months," she says, laughing. "They're not going to ask me to come and speak."

Bayh says the last seven years have been "the greatest growth period in my life. These years since cancer came to me have been the most rewarding, the most fulfulling, the happiest in my life. I have learned to value life, to cherish it, to put my priorities in order - and to begin my long-postponed dream of being useful in my own right."

That feeling has accelerated since February. A lymph node in her neck, so small that Marvella Bayh had not detected it, was malignant. As she wrote with Mary Lynn Kotz in Good Housekeeping, she picked up the phone in her kitchen to hear these awful words from her doctor. "I'm afraid I have bad news. The cancer has spread to your bones. It is inoperable. It will be terminal in the future."

Sitting in her flowered and chintzed immaculate office in her home, Bayh talks almost matter-of-factly about that shattering day. She remembers sobbingM "I feel so well I look so well. How could it be in me?"

She pauses. "I had gone over six years. I had done all the things you were supposed to do. I thought it was just history. Then when they told me there was treatment but no cure at this time, I dropped to my knees. Two things from out of the past, when I went to church as a child, came back to me. Number one, "Where can I go but to the Lord?" and number two, "I am weak but he is strong."

"The third feeling I had was, "When life comes down to basics, really how little control we all have over our own lives." And it also came to me how, even if we live to be 100, how really short life here is. And therefore, it's important to enjoy it and not rush so fast and take time to smell the roses . . . And if there is something important for you to do, to do it, and not put it on the back-burner. If it's important to you to take art lessons, then you take them. If it's important to you to tell somebody you love them, then you tell them.

"I'm not dearly so much the perfectionist anymore into perspective. I mean those things that seemed so important before - w hether it's a trip to climb the Matterhorn . . . or your child getting into a certain college, or what the things that we really important are your relationship with your God and your relationship with your fellowman.

"Another thing I learned is that each and every person out there can make such an overwhelming difference in the lives of other people" Marvella Bayh recalls the hundreds of former patients who supported her through these years. And one anonymous note that kept her going, seven years ago when she was undergoing daily radiation treatments at George Washington Hospital.

"It's not life's happiest time. And I got to the point where I was feeling pretty . . ." she pauses to choose the right word, "listless. And I thoought, 'I don't know if I want to finish these anymore.' Our car is easy to identify because of the Senate license plate. One day I came out of the hospital and there was a note under the windshiled, on spiral paper, scribbled with pencil: 'I see your car parked here almost every day, Mrs. Bayh. Hang in there, Others are thinking of you.' I brought that note home and kept it by my bedside until I finished those radiation treatments. You don't have to be a president of the United States or a senator to make a difference in peoples' lives. You can touch them all around you every day."

Marvella Bayh's life has been shaped by tragedy and success. "The peaks have been unbelievable," she says, "but the valleys have been pretty bad." Marvella Bayh is a survivor.

Her mother was ill all her life; her father, whom she worshipped as a child, became an alcoholic after her mother's death, remarried and then one night shot and killed her stepmother and then himself. Marvella was in a car accident while in college which left her with double vision for months. Both Marvella and Birch Bayh were in a plane crash with Ted Kennedy, an accident that killed two people. And now, her cancer.

From her earliest days she has a need and a flair to excel in the farm world of Enid. Her mother's spine was ruptured when Marvella was born and her health grew increasingly worse. Though ill with a "heart and nervous condition," Marvella says, "my mother did a lot for me." At 3, Marvella was already taking elocution lessons and entering speech contests at 4. Her mother had to teach her the readings, because she could not yet read.

"I never got the feeling I was being driven, but my parents always made me feel I could accomplish everything anyone else could. I was never "just a girl. I was their boy and girl together," she once said.

On the walls of her office hang the memorabilia: signed photos from Lyndon and Lady Bird, a picture of Birch "to the girl of my dreams," pictures of her son, Evan, a law student at the University of Virginia. She points to a pen on a table sent the other day by President Carter after the signing of the ERA extension, for which she had lobbied. And on the wall in one corner is her Pride of the Plainsmen Award, given to her by her hometown when Marvella Bayh was the 1950 President of Girls' Nation.

"I went to the White House to meet President Truman; he met with us in the Rose Garden and we were so excited," she recalled a few years ago. "We all brought gloves to wear for the occasion. I presented him with a citation and, oh, do you remember how they had the 'News of the Week' at movie houses? When I went back to Oklahoma and I went to the movies and they ran that newsreel, there I was on the film. When I came home from Girls' Nation, they had a big parade for me to welcome me back home. If I had lived in a big city like Detroit or Chicago or Washington, D.C., that never would have happened."

Her sunny life continued - winning debates, beating another student named Birch Bayh (He often says, "She won te contest, but I won the girl"), the long climb off the farm, through law school, then urging Burch to run for the Senate.

But throughout those early striving days in Washington when the Bayhs were entertaining all the right people and working hard with the White House as their goal, there was a major sorrow in her life. Her father's alcoholism.

"To lose the closeness with my father, that was worse than the death," she once said. "When I was growing up, he was a fantastic teetotaler. But shortly after I married he became a total alcoholic. Then he remarried very quickly after Mother's death. Too quickly. It was a bad match. After about five or six years of that his mind went. He shot her and himself on the last night in March (1970).

"Dad would call me on the phone, drunk. My heart was racing, just racing. It would wake me up at night. He and I were so close, but for the sake of my own health and family I got to a place where I put him out my heart." When he died, Marvella Bayh was in Europe and read the glaring headlines; political prominence again provided no shelter from a public accounting of private disasters. Nor was her husband at the airport to meet her, because on the ongoing Senate debate on the appointment of G. Harold Carswell.

"When I spoke at daddy's funeral, I said the man people knew for the last seven years was not the real man they knew. If there was a shut-in on the block, he'd be there. He was always the one driving the kids to school things. He never missed any of my performances. When I was a little girl every vehicle on the farm - the combine, mower, trailer - every one had a little seat on it for me."

Today, as she looks back over the trials in her life, Marvella Bayh says, "I had this survival instinct. Not with my father, not even at the time of my mastectomy did I turn to God. With my father, it was more of an intellectual acceptance. I knew I had to accept it or break. But I carried everyone of those loads without God sharing it with me. And when I think that I carried it alone needlessly! I hunt myself a lot. But this time, I realized that determination and a sense of survival was not enough."

Marvella Bayh - who refers to her helpmate days with some residual bitterness as a "fulltime, unpaid assistant to my husband" - has some longing that she did not push earlier for a career of her own. "But then I was a product of the time." Since she has moved into her own career with the American Cancer Society, "Birch has been very, very supportive. Like many people, he had lot of growing to do. I can remember him once saying to me before my cancer experience, "What is it you want that I haven't given you?" He'd never say that today. He takes happiness in my fulfillment."

There seems to be a genuine serenity and fulfillment to Marvella Bayh that transforms her from the woman of the '60s with the perpetual and ubiquitos political smile.

"It comes from my faith in God," she says. "Would I call it 'born again?' It depends on how you define born again. I didn't have any flash of lightning or drums rolling in the background or anything like that. But I had a moment. I had a moment of great need. And God was just waiting for me and it began at that moment. It has been a growth process. I spent a lot time reading religious literature, reading the Bible. There's a ministry center in Indiana that I call on the telephone when I have questions as I am reading.I'm in the 'first grade' and I'm learning.

"My walk with my God is growing each day. You know that you are not alone. That you will never be left alone. That God is always the same. Yesterday, today - and tomorrow."