Every woman with advanced breast cancer, meaning 55 percent of all who get it, should have two years of chemotherapy after surgery, three leading cancer doctors said yesterday.

They recommended this not only to women who have not yet reached menopause -- where it has been applied for the past few years -- but also to women past menopause, a far larger group.

One woman in 11 develops breast cancer. Of those who do, three of four do so after menopause.

"Advanced" breast cancer means that some has spread or "disseminated" to nearby lymph nodes, which means that it is likely to spread elsewhere.

Latest statistics presented to the nation's cancer specialists indicated that only 40 percent of women with disseminated disease can expect to live five years after surgery alone. With chemotherapy, this number should reach 60 percent, according to doctors conducting cooperative trials of many methods at scores of hospitals.

Until this week, most cancer experts were saying that "adjuvant chemotherapy" -- use of anticancer chemicals after surgery -- had been proved effective only for women who have not yet passed through menopause. Now it is clearly "the" treatment for post-menopausal women too, said Drs. James Holland of Mount Sinai Medical School in New York, Bernard Fisher of the University of Pittsburgh and Saul Rivkin of Swedish Hospital in Seattle.

Not every doctor agrees. "We still enter post-menopausal women into studies" with some getting chemotherapy after surgery and some having surgery alone, said Dr. Charles Moertel of the Mayo Clinic in Rochester, Minn. "We still want more information."

But Holland, Fisher, Rivkin and doctors from several other centers gave optimistic reports on adjuvant chemotherapy to the American Society of Clinical Oncology (cancer treatment) meeting here. They said the picture in breast cancer treatment is changing fast and all the latest evidence points to the need for more chemotherapy.

"What has happened in this field is extraordinary," Holland said, "and it has almost all happened in the last 10 years. The concept of surgery alone is no longer an adequate concept for [disseminated] breast cancer."

Holland said a five-drug combination tested at 30 centers has proved superior to a widely used three-drug combination. The three drugs are cyclophosphamide, methotrexate and 5-fluorouracil. Holland and others added vincristine and prednisone, a combination first used by Dr. Richard Cooper of Buffalo General Hospital.

However, Fisher, a leader in many of the most important cooperative trials, said these combinations have not yet been proved universally better than still another two-drug treatment or, sometimes, treatment with a single drug.

"I think we're still in the process of finding out if more drugs are better," he said.

"The main point," he added, is that breast cancer is a complicated and "heterogeneous" disease, depending on the number of lymph nodes involved and other factors. Different women need different approaches.

"There are two things a woman with this disease must do now," he concluded.

"First, breast cancer can no longer be treated by the casual doctor who treats a few patients a year, and a woman must find out" whether her doctor makes treating cancer a main effort.

"And, second, I'd ask the doctor, 'Do you participate in clinical trials [comparative studies of treatment methods]?' I wouldn't imply that some good persons don't participate. But if the answer is yes, this doctor is more likely to be at the leading edge."