In Sunday's editions, captions were reversed for Donald C. McIlrath and Oliver Beahrs, two physicians involved in First Lady Nancy Reagan's cancer surgery. (Published 10/20/87)

The report from Nancy Reagan's doctors that her breast tumor was less than a quarter-inch across and had not started to invade nearby tissues was interpreted by experts yesterday as a virtual guarantee that her cancer has been surgically cured.

The news "is just about as good as it could have been," said Dr. John E. Martin, a professor of radiology and mammography expert at the University of Texas M.D. Anderson Hospital Tumor and Cancer Institute. He added, "I imagine there's going to be a stampede in the next month" of women wanting mammograms.

"The big message of this situation is the fact that mammography can find a cancer when it is too small to be felt by the most experienced physicians," said Dr. Arthur I. Holleb, chief medical officer of the American Cancer Society.

The tumor was described as a noninvasive, intraductal adenocarcinoma, which means that it was a cancer of the cells lining one of the breast's many milk ducts and that it had not spread outside the duct or tube where it originated. "It's a very small, very early cancer," said Dr. William F. Feller, an associate professor of surgery at Georgetown University Medical Center.

With this size and type of tumor, Feller estimated that the chances were less than one percent that any of the lymph nodes removed from the armpit would be found to contain cancer cells.

Experts yesterday said the favorable report could be attributed to a combination of good luck and regular medical care, particularly the fact that Nancy Reagan has had annual mammograms, special X-rays of the breasts to check for cancer.

Martin said that the cancer, which measured 7 millimeters in diameter -- less than one-quarter inch -- probably showed up on the mammogram as a collection of tiny white flecks called calcifications. He said an expert mammographer can sometimes spot calcifications in a cancer when it is only 1 or 2 millimeters across.

Feller said that less than 5 percent of all breast cancers are found at such an early, curable stage, although the proportion is gradually rising as more women have regular mammograms. Nancy Reagan's breast cancer was seen on a mammogram when it was so small that doctors could not feel it.

In contrast, 70 percent of breast cancers are discovered by women themselves, showing up as a lump in the breast. If a tumor is large enough to feel, it is more likely to have spread to the lymph nodes or elsewhere in the body.

The American Cancer Society recommends that women obtain their first mammogram between age 35 and 39, that they have a mammogram every one or two years from 40 to 49 and that the test be done yearly in women 50 or older. The National Cancer Institute is considering adopting the same guidelines.

Holleb of the American Cancer Society said that when mammograms were first introduced, they delivered substantial radiation doses to the breasts, raising concerns that a woman's risk of breast cancer might rise because of radiation exposure if she had the test done frequently. But he said improvements in mammography in the last two decades had reduced the X-ray dose by more than a hundredfold, and that experts no longer believe radiation from mammograms affects breast cancer risk.

Breast cancer is the second most common cause of cancer deaths among women, following lung cancer. More than 130,000 new cases of breast cancer will be reported in the United States this year, and about 41,000 women will die of the disease, according to the National Cancer Institute.

The five-year survival rate for all breast cancer patients is 75 percent, according to the NCI. But the five-year survival rate in a recent study for women with intraductal, noninvasive cancers like Nancy Reagan's was 98 percent.

So favorable is the prognosis in such small, noninvasive tumors that many experts believe removal of the entire breast in such cases is unnecessary.

"It gets down to a very personal decision" by the woman and her doctor, said Dr. Martin Abeloff, chief of medical oncology at Johns Hopkins University Medical School. "No one knows the best way . . . . Mastectomy is probably still the most standard approach for this."

Abeloff said two other treatments, both of which preserve the breast, are being compared in a randomized trial of patients with intraductal cancers by Dr. Bernard Fisher of the University of Pittsburgh. He said half the patients in that trial receive a "lumpectomy," surgery to remove only the tumor and a small margin of surrounding, normal tissue. Then they are closely observed to see if the cancer recurs. The other half receive a lumpectomy followed by a series of radiation treaments of the breast.

Rose Kushner, executive director of the Breast Cancer Advisory Center in Kensington, said recent evidence suggests that Nancy Reagan could have been effectively treated with less extensive surgery than a mastectomy. She said she advises women with suspected breast cancer to undergo a biopsy first, then to discuss their options with their doctors before deciding how the cancer should be treated.

But she added that many women over 65 prefer to have a single procedure, as Nancy Reagan did, in which the biopsy and definitive surgery are performed at the same time.

"She did what I've been fighting that women should be allowed to do, and that is, she did what she wanted to do," Kushner said yesterday.

Once a woman has had even a small, noninvasive breast cancer, her risk of developing a new cancer is about 1 percent per year, according to Georgetown's Feller. He said Nancy Reagan's surgeons will probably examine her about every six months, and that she should have mammograms done every six months or every year. He said she should also have regular chest X-rays. BREAT BIOPSY AND MASTECTOMY

1

Using local anesthesia, a radiologist inserts a fine needle into the breast to pinpoint the area that has shown a possible cancer on an X-ray. A mammogram, a special X-ray of the breast, will then be taken with the needle in place to be sure it is pointing to the right spot.

With the needle in place as a marker, the patient will be taken to the operating room, and anesthesized. Surgeons then perform the biospy, talking a sample of breat tissue from the are around the needle's tip. A mammogram is done of the sample to make sure it contains the area of possible cancer. Then a pathologist examines frozen sections of the biopsy sample for cancer.

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If cancer is found, most women choose between two equally effective treatments: a modified radical mastectomy or a partial mastectomy ("lumpectomy") and lymph node removal combined with subsequent radiation therapy to the breast.

In a modified radical mastectomy, surgeons remove the entire breast, but leave the underlying chest muscles intact. They also remove the lymph nodes underlying the breast and in the armpit. The nodes will then be examined to determine whether the cancer has spread.