RADIATION TREATMENT OK TO AVOID.

Byline: Phil Davis Daily News Staff Writer

Thousands of women with a common form of breast cancer don't have to undergo radiation treatments to prevent the cancer from recurring, a University of Southern California researcher reported.

Simply cutting one centimeter of tissue around a cancerous area can spare women with ductal carcinoma in situ (DCIS) from the unpleasant side effects of radiation treatments, said Dr. Melvin J. Silverstein, lead author of the study to appear in today's New England Journal of Medicine.

``It's a big deal,'' said Silverstein, director of the USC Breast Center. ``We are changing the way we treat a certain kind of breast cancer. We're doing less treatment and getting the same results. That's a win-win scenario.''

DCIS is breast cancer at its earliest stage. It has not yet developed the ability to spread to other parts of the body. About 40,000 women a year are diagnosed with DCIS, roughly 18 percent of all breast cancer cases. The numbers are on the rise as more women have mammograms and are diagnosed earlier.

Surgeons have long suspected that simple surgery could treat DCIS, but until Silverstein's study there was no hard data to go on. The only study on the topic, written 14 years ago when DCIS was not known to be as prevalent, recommended radiation treatment following an excision or lumpectomy.

Silverstein and his colleagues at the Van Nuys Breast Center and St. Mary's Hospital in San Francisco began their research in 1979 with the hopes of discovering a less invasive treatment. Since then, the scientists have studied more than 500 DCIS cases where the cancerous lesion was removed with varying margins of healthy tissue.

Their research found that, in the group of patients where one centimeter of healthy tissue was removed along with the mutated cells, only three of 133 patients suffered a recurrence of the cancer. That outcome is statistically as good as patients who received follow-up radiation treatment. That led the researchers to conclude radiation is unnecessary as long as the cancer removed is bordered on all sides by a wide margin of healthy tissue.

Women who have large DCIS tumors may still need a masectomy. And patients whose excisions remove less than the one centimeter of healthy tissue should still consider radiation treatment, the study found. One centimeter is .4 inches.

Many women opt to skip the radiation, anyway, fearing they might need the one-time only treatment if a more aggressive and lethal cancer invaded their bodies. Radiation therapy, which can cost $15,000, also hardens tissue and makes breast reconstruction difficult.

Silverstein's challenge to the conventional wisdom that all DCIS patients need radiation promises to fuel an ongoing debate. Dr. Lawrence D. Wagman, chairman of the division of surgery at City of Hope Cancer Center, said the study fell short of convincing him to stop advising radiation for DCIS patients who chose excision over masectomy.

``The study is too small to make sweeping conclusions,'' Wagman said. ``I agree with the conclusion that we can identify women who might not need radiation. But there are elements that need to be clarified in a larger study.''

But in its editorial, the New England Journal of Medicine praised the study as a model of efficiency. The study demonstrates ``important medical goals can be achieved without a multicenter clinical trail if strict case definitions and precise guidelines are used,'' the editors wrote.

The news that radiation isn't always necessary is a welcome relief to patients like Jean O'Leary, a Northridge businesswoman and Democratic National Committee official who had a small DCIS cancer lesion removed at USC in December.

``It's peace of mind. It's such a relief to not have to be always looking over your shoulder,'' she said. ``Why pull out all this big artillery on a tiny little cancer? The lesson here is to get a mammogram.''

The surgery - as described in Silverstein's study - can be tricky, though. Surgeons at USC use guide wires to help them remove the proper amount of tissue. The tissue is then checked in the operating room and more is removed if the first cut failed to achieve the desired margin.

``The cosmetic impact should be minimal,'' Silverstein said. ``The surgeon must know how to make the breast look good when he or she is finished.''

O'Leary is pleased with the results of her surgery.

Silverstein ``did a wonderful job,'' she said. ``Even though he took out quite a piece there is no indentation.''