Women with breast cancer that has not yet invaded the lymph nodes may have new treatment options, according to four major clinical studies - one of which included investigators at the Utah Regional Cancer Center at the University of Utah Hospital.

The trial reports, published in The New England Journal of Medicine, show that women receiving chemotherapy or hormonal therapy are more likely to remain disease-free during the first three or four years after primary therapy - mastectomy, or lumpectomy and radiation therapy.Of the approximately 142,000 American women who are diagnosed with invasive breast cancer each year, about half are node-negative, meaning the cancer has not spread to nearby underarm lymph nodes, according to the National Cancer Institute.

And of the 70,000 women who are node-negative, 25 to 30 percent will have a disease recurrence, said Dr. Harmon J. Eyre, an oncologist at the U. School of Medicine and immediate past president of the American Cancer Society.

Eyre was a principal investigator in one of the three trials funded by the National Cancer Institute. The fourth trial was an international study, headquartered in Switzerland.

The four experiments sought ways to reduce the mortality rate among those women, Eyre said. And in all four studies, treated women did better.

"Two things can reduce a woman's risk of dying from this disease," Eyre said. "One is finding the tumor early, by physical examination or mammogram screening. The second - and this is where the trial findings are especially significant - is getting good treatment afterward.

"Women diagnosed with node-negative breast cancers should be encouraged to discuss the options for additional treatment with informed physicians, with the understanding that each case must be assessed on an individual basis," he said.

The investigators said node-negative women generally have received only surgery or surgery and radiation because it was thought that cancer spread in an orderly fashion from the breast to adjacent lymph nodes and then to other parts of the body.

Now it is understood that, even if cancer is not detected in underarm lymph nodes, cancer cells may have gone to distant parts of the body and may cause illness years later. And systemic treatments, such as hormone therapy or chemotherapy, are the only way such scattered cells can be reached.

The American Cancer Society, however, said further studies are necessary to determine the survival increase versus the toxicity of the therapy.

The NCI said more time is needed to determine if the additional treatment is responsible for the improved survival rate in addition to reduction of disease recurrence.

Women with non-invasive breast cancers were not included in the trials because additional therapy is not considered necessary for them, according to the NCI.

Also excluded were patients with tumors so small that hormonal receptor status could not be determined. Current data in these cases is insufficient to indicate whether additional therapy is beneficial.